Systems and methods for monitoring and controlling air quality in enclosed spaces

Abstract

A system for monitoring and controlling air quality within an enclosed space (S) includes a controller (11), a sensor (12) that monitors environmental parameters inside the enclosed space (S), an air flow distribution balancer (14) that receives an external air flow from outside the enclosed space and an internal air flow from inside the enclosed space, and an air flow generator (16) that generates the external air flow. The controller (11) and the sensor (12) are in operative communication. The controller (11) is configured to receive an input signal from the sensor (12). In response to the input signal, the controller (11) is configured to generate an output signal that is sent to the air flow distribution balancer (14) and / or the air flow generator (16) to control operation of the air flow distribution balancer (14) and / or the air flow generator (16), respectively, thereby controlling one or more environmental parameters related to the air quality inside the enclosed space (S) by adjusting the volume of external air and / or the volume of internal air delivered to the enclosed space (S).

Description

[Technical Field]

[0001] The present invention relates to a system and method for monitoring and controlling air quality within a confined space. Specifically, the present invention monitors and controls one or more environmental parameters related to air quality inside a confined space by controlling air flow into the confined space, thereby controlling the air quality inside the confined space. The confined space may be, for example, a cabin or a cabinet. Examples of environmental parameters within the confined space that can be controlled include dust contaminant levels and levels of undesirable gases, such as carbon dioxide, hydrogen sulfide, and / or sulfur dioxide (CO2, H2S, and / or SO2). Additionally, the present invention relates to an airflow distribution balancer. The airflow distribution balancer can be used in the system of the present invention, i.e., a system for monitoring and controlling air quality within a confined space. [Background technology]

[0002] Throughout this specification, unless the context requires otherwise, the terms "comprises," "comprising," and variations thereof such as "comprises," "comprises," and "comprises" should be understood to imply the presence of a stated integer or group of integers, but not the exclusion of other integers or groups of integers.

[0003] Throughout this specification, unless the context requires otherwise, the word "comprises" and variations such as "comprising" and "included" should be understood to imply the presence of a stated integer or group of integers, but not the exclusion of other integers or groups of integers.

[0004] Headings and subheadings herein are provided for convenience to assist the reader and should not be construed to narrow or limit the scope of the present disclosure in the specification, claims, abstract, or drawings.

[0005] The discussion of the background art, references to documents, and references to publicly known or commonly held information contained in this specification are provided solely for the purpose of facilitating an understanding of the background to the invention, and the references themselves do not constitute an admission or endorsement that any of the material formed part of the common general knowledge in Australia or any other country at the priority date of the related application in which this specification was filed.

[0006] It is a common requirement for HVAC systems to seek to control the circulation of air within the enclosed space in which they are intended to be used. Existing devices may employ, for example, various valve designs, system configurations, and control systems to consider either pressure, CO2 (carbon dioxide), or dust levels within the enclosed space and control the operation of components in response to such levels. However, existing systems are designed to meet the needs of the specific application for which the particular system is intended. Such systems are not necessarily intended to be retrofittable to existing HVAC systems as aftermarket accessories in addition to OEM (original equipment manufacturer) systems. Summary of the Invention

[0007] According to one aspect of the present invention, a system for monitoring and controlling air quality within an enclosed space is provided. According to another aspect of the present invention, there is provided an airflow distribution balancer, which may be a component of a system for monitoring and controlling air quality within an enclosed space.

[0008] Thus, according to one aspect of the present invention, there is provided a system for monitoring and controlling air quality in an enclosed space, the system comprising: A controller; one or more sensors for monitoring one or more environmental parameters inside the enclosed space; at least one air flow distribution balancer for receiving a first air flow of external air from outside the enclosed space and a second air flow of internal air from inside the enclosed space; an air flow generator for generating at least a first air flow of external air; Equipped with The controller and the one or more sensors are in operative communication, and in use, the controller is configured to receive one or more input signals from the one or more sensors, and to generate one or more output signals in response to the one or more input signals, which are sent to at least one of the air flow distribution balancer and the air flow generator to control operation of at least one of the air flow distribution balancer and the air flow generator, respectively, to control one or more environmental parameters related to air quality inside the enclosed space by adjusting at least one of the volume of external air and the volume of internal air delivered to the enclosed space.

[0009] In one or more embodiments, the air flow distribution balancer comprises at least one inlet for air to enter the air flow distribution balancer as an inlet airflow and an outlet for air to exit the air flow distribution balancer as an outlet airflow.

[0010] The air flow distribution balancer described herein comprises a chamber that receives air that enters the air flow distribution balancer via at least one inlet. In one or more embodiments, the airflow distribution balancer comprises at least one door movable to selected positions, wherein the at least one inlet is fully closed when the at least one door is in a first position, fully open when the at least one door is in a second position, and partially open and partially closed when the at least one door is in an intermediate position between the first and second positions. In use, when the at least one door is in the first position such that the at least one inlet is fully closed, air cannot flow through the at least one inlet, and when the at least one door is in the second or intermediate position such that the at least one inlet is fully open or at least partially open, air can flow through the at least one inlet into the chamber and out the outlet.

[0011] In one or more embodiments, the air flow distribution balancer further comprises at least one motor, and the at least one door and the at least one motor are operatively connected such that the at least one motor is operable to move the at least one door.

[0012] In one or more embodiments, the at least one motor is operable to move the at least one door in response to a signal received from the controller. In one or more embodiments, the air flow distribution balancer includes a first inlet, a second inlet, and an outlet. The first inlet and the second inlet each receive an inlet airflow. The first inlet receives a first airflow of external air from outside the enclosed space, and the second inlet receives a second airflow of internal air from inside the enclosed space. The outlet airflow exits the air flow distribution balancer through the outlet.

[0013] In one or more embodiments, the first entrance and the second entrance include respective doors as described above that are movable to selected positions as previously described herein. In one or more embodiments, the air flow distribution balancer comprises first and second motors, each door operatively connected to the first and second motors such that the first and second motors are operable to move the respective door.

[0014] In one or more embodiments, the system includes a first airflow distribution balancer that receives a first airflow of external air and a second airflow distribution balancer that receives a second airflow of internal air.

[0015] In one or more embodiments, the system further comprises a first bypass valve that allows a portion of the air from the enclosed space to return to the enclosed space instead of entering the second air stream. In one or more embodiments, the system further comprises a first filter that filters a portion of the air before it is returned to the enclosed space via the first bypass valve.

[0016] In one or more embodiments, the system further comprises a second bypass valve that directs a portion of the air in the outlet airflow into the enclosed space. In one or more embodiments, the system further comprises a second filter that filters the air before directing a portion of the air through the second bypass valve and into the enclosed space.

[0017] The airflow generator is positioned so as to be able to draw air from at least outside the enclosed space and direct the air into the enclosed space. In one or more embodiments, the airflow generator is located outside the enclosed space. In one or more other embodiments, the airflow generator is located inside the enclosed space.

[0018] Air passing through the airflow generator is directed into the enclosed space. The system further comprises a duct for passage of the airflow through the system. In one or more embodiments, the airflow generator includes an air compressor. In one or more other embodiments, the airflow generator comprises a blower. Depending on the particular implementation of the system, the airflow generator may be in the form of an air compressor or a blower. In one or more embodiments, the blower is provided as a high-volume blower.

[0019] The one or more sensors may include one or more of: at least one pressure sensor for sensing pressure inside and outside the enclosed space (i.e., differential pressure sensing) or inside the enclosed space; at least one dust sensor for sensing the presence of dust particles in the enclosed space; at least one CO2 sensor for sensing the presence of CO2 in the enclosed space; at least one airflow sensor for sensing air flow; and / or at least one gas sensor.

[0020] In one or more embodiments of the system, the one or more sensors include at least one pressure sensor. The at least one gas sensor may include one or more gas sensors that sense the presence of a gas, such as, for example, hydrogen sulfide (H2S), sulfur dioxide (SO2), and / or a refrigerant gas, such as, for example, R-1234YF.

[0021] The system may further comprise an air precleaner for pre-cleaning air received from outside the enclosed space before the air enters the at least one inlet of the air flow distribution balancer.

[0022] In one or more embodiments, the system further comprises at least one particulate filter for filtering particulate matter from at least the first air flow of outside air. In one or more embodiments, at least one particulate filter is provided as a separate filter.

[0023] In one or more embodiments, at least one particulate filter is provided within the air pressurizer. In one or more embodiments, the system further comprises at least one activated carbon filter for filtering undesired gases from at least the first air flow and / or the outlet air flow, hi one or more embodiments, at least one particulate filter is provided upstream of the activated carbon filter.

[0024] According to another aspect of the present invention, there is provided an air flow distribution balancer, the air flow distribution balancer comprising: a casing having at least a first inlet and an outlet; a chamber inside the casing; at least one door movable to selected positions, the at least one entrance being fully closed when the at least one door is in a first position, fully open when the at least one door is in a second position, and partially open and partially closed when the at least one door is in an intermediate position between the first and second positions; In use, when the at least one door is in the first position, air cannot flow through the at least one inlet, such that the at least one inlet is fully closed, and when the at least one door is in the second or intermediate position, air can flow into the chamber through the at least one inlet and out the outlet, such that the at least one inlet is fully open or at least partially open.

[0025] In one or more embodiments, the air flow distribution balancer further comprises at least one motor, and the at least one door and the at least one motor are operatively connected such that the at least one motor is operable to move the at least one door.

[0026] In one or more embodiments, the air flow distribution balancer comprises a first inlet, a second inlet, and an outlet. In one or more embodiments, the first entrance and the second entrance include respective doors as described above that are movable to selected positions as previously described herein.

[0027] In one or more embodiments, the air flow distribution balancer comprises first and second motors, each door operatively connected to the first and second motors such that the first and second motors are operable to move the respective door.

[0028] According to another aspect of the present invention, there is provided a method for monitoring and controlling air quality in an enclosed space, the method comprising: monitoring one or more environmental parameters inside the enclosed space; generating at least a first air flow of external air from outside the enclosed space with an air flow generator; receiving a first air flow of external air and a second air flow of internal air from inside the enclosed space at at least one air flow distribution balancer; delivering air from the at least one air flow distribution balancer to the enclosed space with an outlet air flow; generating one or more input signals indicative of one or more environmental parameters inside the enclosed space; generating one or more output signals in response to one or more input signals; and transmitting one or more output signals to at least one of the air flow distribution balancer and the air flow generator to control operation of at least one of the air flow distribution balancer and the air flow generator by adjusting at least one of the volume of external air and the volume of internal air delivered to the enclosed space, thereby controlling one or more environmental parameters related to air quality inside the enclosed space.

[0029] In one or more embodiments of the methods described herein, receiving a first air flow of external air and a second air flow of internal air from inside the enclosed space at at least one air flow distribution balancer includes receiving the first air flow of external air and the second air flow of internal air at a single air flow distribution balancer.

[0030] In one or more embodiments of the methods described herein, receiving a first air flow of external air and a second air flow of internal air from inside the enclosed space at at least one air flow distribution balancer includes receiving the first air flow of external air at a first air flow distribution balancer and receiving the second air flow of internal air at a second air flow distribution balancer.

[0031] In one or more embodiments of the method described herein, the method further includes returning a portion of the air to the enclosed space via the first bypass valve rather than allowing the portion of the air from the enclosed space to enter the second air stream.

[0032] In one or more embodiments of the method described herein, the method further includes filtering the air before returning a portion of the air to the enclosed space via the first bypass valve. In one or more embodiments of the method as described herein above, the method further comprises directing a portion of the air in the outlet air stream into the enclosed space via a second bypass valve.

[0033] In one or more embodiments of the method described herein, the method further includes filtering the air before directing a portion of the air through the second bypass valve and into the enclosed space. "External air" received from outside the enclosed space is also referred to herein as "fresh air." "Internal air" received from inside the enclosed space is also referred to herein as "recirculated air." A "first air flow" of external air received from outside the enclosed space is also referred to herein as "fresh air flow." A "second air flow" of internal air received from inside the enclosed space is also referred to herein as "recirculated air flow." The inlet air flow to the air flow distribution balancer includes the first air flow and / or the second air flow.

[0034] Dust particles are also referred to herein as particulates or particulate matter. Similarly, dust sensors are also referred to herein as particulate sensors. The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0035] [Figure 1A] 1 is a schematic diagram of a first embodiment of a system for monitoring and controlling air quality in an enclosed space, installed in a vehicle, according to an aspect of the present invention; [Figure 1B] FIG. 1B is a schematic diagram illustrating the inclusion of an additional separate filter in the system shown in FIG. 1A. [Figure 2] 1B is a perspective view of the interior of a vehicle cabin in which the system shown in FIG. 1A is installed. [Figure 3A] FIG. 3 is a rear view of the cabin shown in FIG. 2. [Figure 3B] 3B is a cross-sectional view through a portion of the shell wall of the vehicle cabin shown in FIG. 3A illustrating an embodiment of a differential pressure sensor of the system shown in FIG. 1A. [Figure 4] FIG. 2 is a schematic diagram of a second embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 5]FIG. 10 is a schematic diagram of a third embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 6] FIG. 10 is a schematic diagram of a fourth embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 7] FIG. 10 is a schematic diagram of a fifth embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 8] FIG. 10 is a schematic diagram of a sixth embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 9] FIG. 10 is a schematic diagram of a seventh embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 10] FIG. 10 is a first cutaway view of a return air unit of an HVAC system for use with the systems of the third to seventh embodiments shown in FIGS. 5 to 9. [Figure 11] FIG. 11 is a second cutaway view of the return air unit shown in FIG. 10. [Figure 12] 12 is a first perspective view of a first embodiment of an air flow distribution balancer for use in the system shown in FIGS. 1A-11, according to another aspect of the present invention. FIG. [Figure 13] FIG. 13 is a second perspective view of the air flow distribution balancer shown in FIG. [Figure 14] 13 is a first internal view of the air flow distribution balancer shown in FIG. 12 with a portion of the casing removed. FIG. [Figure 15] 13 is a second internal view of the air flow distribution balancer shown in FIG. 12 with a portion of the casing removed. FIG. [Figure 16] 13 is a third internal view of the air flow distribution balancer shown in FIG. 12 with a portion of the casing removed. FIG. [Figure 17] FIG. 13 is a perspective view of the lower portion of the airflow distribution balancer shown in FIG. 12, showing the motor assembly and motor housing. [Figure 18]FIG. 13 is a perspective view of the motor assembly and closing door of the air flow distribution balancer shown in FIG. 12. [Figure 19] FIG. 19 is an exploded view of the motor assembly and closing door shown in FIG. 18. [Figure 20] 12 is a perspective view of a second embodiment of an airflow distribution balancer for use in the system embodiment shown in FIGS. 1A-11, according to another aspect of the present invention. FIG. [Figure 21] 12 is a first perspective view of a third embodiment of an air flow distribution balancer for use in the system embodiments shown in FIGS. 1A-11, in accordance with another aspect of the present invention. FIG. [Figure 22] 22 is a first internal view of the air flow distribution balancer shown in FIG. 21 with a portion of the casing removed. FIG. [Figure 23] 22 is a second internal view of the air flow distribution balancer shown in FIG. 21 with a portion of the casing removed. FIG. [Figure 24] 23 is an exploded view of the airflow distribution balancer shown in FIG. 22 with the motor assembly and motor housing separated from the casing of the airflow distribution balancer. [Figure 25A] 25A-25D are flow diagrams of the control system's operating processes: "Normal System Operation" (FIG. 25A), "Calibration Function Operation" (FIG. 25B), "Air Quality Operation Check Operation" (FIG. 25C), and "Scrub Mode Operation" (FIG. 25D). [Figure 25B] 25A-25D are flow diagrams of the control system's operating processes: "Normal System Operation" (FIG. 25A), "Calibration Function Operation" (FIG. 25B), "Air Quality Operation Check Operation" (FIG. 25C), and "Scrub Mode Operation" (FIG. 25D). [Figure 25C] 25A-25D are flow diagrams of the control system's operating processes: "Normal System Operation" (FIG. 25A), "Calibration Function Operation" (FIG. 25B), "Air Quality Operation Check Operation" (FIG. 25C), and "Scrub Mode Operation" (FIG. 25D). [Figure 25D]25A-25D are flow diagrams of the control system's operating processes: "Normal System Operation" (FIG. 25A), "Calibration Function Operation" (FIG. 25B), "Air Quality Operation Check Operation" (FIG. 25C), and "Scrub Mode Operation" (FIG. 25D). [Figure 26] FIG. 10 is a flow diagram of the control system computation process for "Cost Function Computation." [Figure 27] FIG. 10 is a schematic diagram of an eighth embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 28] FIG. 28 is a perspective view of the upper rear portion of the cabin of a vehicle in which the system shown in FIG. 27 is installed. [Figure 29] 28 is a first cutaway perspective view showing the interior of a vehicle cabin in which the system shown in FIG. 27 is installed. [Figure 30] 28 is a second cutaway perspective view showing the interior of a vehicle cabin in which the system shown in FIG. 27 is installed. [Figure 31] 28 is a third cutaway perspective view showing the interior of a vehicle cabin in which the system shown in FIG. 27 is installed. [Figure 32] FIG. 32 is a perspective view of a fifth embodiment of an air flow distribution balancer for use in the system embodiments shown in FIGS. 27-31, according to another aspect of the present invention. [Figure 33] FIG. 10 is a cutaway perspective view of an alternative embodiment of the return air unit, showing an alternative embodiment of the filter, for the third to eighth embodiments of the system. [Figure 34] FIG. 34 is an exploded perspective view of the return air unit shown in FIG. 33. [Figure 35] FIG. 13 is a schematic diagram of a ninth embodiment of a system for monitoring and controlling air quality in an enclosed space, according to an aspect of the present invention. [Figure 36] FIG. 36 is a first diagram illustrating the air flow path through the components of the system shown in FIG. 35 when the bypass valve is closed. [Figure 37] FIG. 36 is a second diagram illustrating the air flow path through the components of the system shown in FIG. 35 when the bypass valve is open. [Figure 38]FIG. 16 is a schematic diagram of a tenth embodiment of a system for monitoring and controlling air quality in an enclosed space, in accordance with an aspect of the present invention. [Figure 39] FIG. 39 is a first diagram illustrating the air flow path through the components of the system shown in FIG. 38 when the bypass valve is closed. [Figure 40] FIG. 39 is a second diagram illustrating the air flow path through the components of the system shown in FIG. 38 when the bypass valve is open. DETAILED DESCRIPTION OF THE INVENTION

[0036] The same reference numerals are used to denote the same or equivalent parts and features in the embodiments described herein. Parts and features described with reference to one or more embodiments will not be described again with reference to other embodiments described herein. It will be understood that the description of such parts and features and their use and operation with reference to such one or more embodiments also applies to other embodiments.

[0037] System and equipment overview DETAILED DESCRIPTION OF THE INVENTION Embodiments described herein include embodiments of systems and methods for monitoring and controlling air quality within enclosed spaces.

[0038] The enclosed space (in which air quality is monitored and controlled) may be a cabin or cabinet. The cabin may, for example, be the cabin of a vehicle. One or more operators of the vehicle may occupy the cabin when the vehicle is in use, and / or equipment may be located within the cabin. The cabinet may, for example, be a cabinet housing equipment (e.g., electronic equipment). However, the enclosed space may also be a building (including a demolition building) or a room occupied by personnel and / or where equipment is located.

[0039] The system may be provided as a retrofit to monitor and control air quality within the enclosed space. Alternatively, the system may be provided within the enclosed space during manufacture of the enclosed space or a product having the enclosed space, such as a vehicle. In a further alternative, the system may be provided within the enclosed space as an upgrade to an existing system within the enclosed space.

[0040] In the described and illustrated embodiment, the confined space S is the interior of a cabin C of a vehicle. The vehicle and cabin C do not form part of the present invention. The vehicle is typically a heavy equipment vehicle, such as those used on mining and construction sites. However, the system and method for monitoring and controlling air quality in a confined space is not limited to use in vehicles. The system and method may be used in any suitable confined space where it is desired to monitor and control the air quality in the confined space in accordance with the present invention. Such suitable confined spaces include, for example, buildings (including demolition buildings), rooms, and cabinets containing sensitive electrical or electronic components, such as servers. Furthermore, the system and method may be used as a security measure for the health and safety of operators in the confined space, as a protection measure for equipment in the confined space, or both.

[0041] One or more environmental parameters related to air quality within the enclosed space S are monitored. Examples of the one or more environmental parameters related to air quality within the enclosed space S that may be monitored include pressure, dust levels, CO2 levels, levels of undesirable gases (e.g., SO2, H2S, and / or refrigerant gases, such as R-1234YF), and airflow. (Refrigerant gases can be hazardous. Thus, if refrigerant gas is detected within the enclosed space S, this may indicate a leak in the vehicle's air conditioning system, and appropriate investigation and corrective action can be taken.) The monitored pressure is the air pressure within the enclosed space S. However, this pressure may also be the air pressure inside the enclosed space S and the air pressure outside the enclosed space. By measuring both the pressure inside the enclosed space S and the pressure outside the enclosed space S, a differential pressure can be calculated. The differential pressure is the difference between the pressure inside and the pressure outside (i.e., inside pressure - outside pressure = differential pressure). It is desirable to maintain a positive differential pressure inside the enclosed space S (i.e., the pressure inside is greater than the pressure outside).

[0042] The cabin C has a shell H that encloses the enclosed space S. The shell H is typically made of metal and glass. The shell H hermetically or hermetically encloses the enclosed space S to reduce the ability of external contaminants in the outside air to enter the enclosed space S, i.e., to isolate the enclosed space S from the external environment outside the cabin C. This includes providing seals at all openings and entry points, such as doors and windows, thereby sealing the enclosed space S from the external environment (as far as practical). The enclosed space S of the vehicle may also be provided with a seat (not shown) for the driver of the vehicle.

[0043] The cabin C contains the operating and electrical equipment for the operation and control of the vehicle, which typically includes the HVAC (heating, ventilation and air conditioning) system. Part of this equipment may include an OEM system, i.e., an OEM computer. This equipment may include a VMS (Vehicle Monitoring System).

[0044] The HVAC system has an air outlet unit U and a return air unit N. Air is discharged from the air outlet unit U to an enclosed space S. Air from the enclosed space S enters the return air unit N for recirculation. The air outlet unit U is equipped with a suitable blower (not shown) for discharging the air into the enclosed space S. In some embodiments, the return air unit N is equipped with a suitable blower B for drawing air from the enclosed space S into the return air unit N (e.g., the embodiments shown in Figures 10 and 11). The return air unit N is provided with a filter T. The filter T may be provided at the air inlet I of the return air unit N. To improve filtration, a fine particle filter may be used as the filter T. The filter T may comprise, for example, a HEPA filter, a ULPA filter, an EPA filter, or other filter capable of filtering fine particles.

[0045] Embodiments of systems and methods for monitoring and controlling air quality in a confined space described herein provide systems and methods for monitoring and controlling air quality by monitoring and controlling airflow into the confined space, thereby monitoring and controlling airflow into the confined space. The monitored and controlled airflows are a first (or fresh) airflow and a second (or recirculated) airflow. As further described herein, embodiments of the systems and methods include a controller in operative communication with or operatively connected to one or more sensors and other components of the systems and methods. The controller receives input signals from the one or more sensors and generates and sends output signals to the components to regulate and control the operation of other components of the system.

[0046] System - First Embodiment Figure 1A is a schematic diagram showing a first embodiment of a system 1 for monitoring and controlling air quality in an enclosed space S, installed in a vehicle having a cabin C. The cabin C is shown in Figures 2 and 3. The cabin C encloses a space that forms the enclosed space S.

[0047] System 1 includes a controller 11, one or more sensors 12, an airflow distribution balancer 14, and an airflow generator 16. The one or more sensors 12 can monitor one or more environmental parameters within enclosed space S. The monitored one or more environmental parameters are indicative of the air quality within enclosed space S. Controller 11 and one or more sensors 12 are in operative communication such that controller 11 can receive one or more input signals from one or more sensors 12. This is represented in FIG. 1A by the dashed line extending between controller 11 and sensors 12. (Dashed lines extending between controller 11 and other components also indicate operative communication between controller 11 and those other components.) In response to the one or more input signals received by controller 11 from the one or more sensors 12, controller 11 can generate one or more output signals that are sent to airflow distribution balancer 14 and / or airflow generator 16 to control operation of airflow distribution balancer 14 and / or airflow generator 16. This is represented in FIG. 1A by the dashed lines extending between the controller 11, the airflow distribution balancer 14 and the airflow generator 16.

[0048] The one or more sensors 12 include at least one pressure sensor 18. The pressure sensor 18 may be a pressure sensor that senses pressure inside and outside the enclosed space S, or the pressure inside the enclosed space S.

[0049] The air flow distribution balancer 14 can receive a first air flow. The first air flow includes outside air. The outside air is air from outside the enclosed space S. Typically, the outside air is ambient air outside the cabin C of the vehicle. The first air flow is a path for the fresh air flow and is also referred to herein as the "fresh air flow." The outside air is also referred to herein as the "fresh air." The fresh air flows into the air flow distribution balancer 14 along with the fresh air flow. In the drawings, the fresh air flow is indicated by arrow F.

[0050] The air flow distribution balancer 14 can receive a second air flow. The second air flow includes internal air. The internal air is air from inside the enclosed space S. The second air flow is a path for a recirculated air flow, also referred to herein as the "recirculated air flow." The internal air is also referred to herein as the "recirculated air." The recirculated air flows into the recirculated air flow to the air flow distribution balancer 14. In the drawings, the recirculated air flow is indicated by arrow R.

[0051] The airflow distribution balancer 14 can adjust how much fresh air and recirculated air is admitted to the airflow distribution balancer 14, as described further herein. During use of the system 1, the fresh air and recirculated air admitted to the airflow distribution balancer 14 exits the airflow distribution balancer 14 as a single airflow (i.e., outlet airflow). As described further herein, the airflow distribution balancer 14 balances the amount of fresh air and the amount of recirculated air that is admitted to the airflow distribution balancer 14 and exits the airflow distribution balancer 14 as a single airflow that is distributed downstream of the airflow distribution balancer 14 to the enclosed space S. In the drawings, the single airflow (i.e., outlet airflow) is indicated by arrow A.

[0052] The airflow generator 16 may receive a fresh air flow F. The airflow generator 16 may receive a recirculated air flow R. The airflow generator 16 is disposed downstream of the airflow distribution balancer 14.

[0053] controller The controller 11 may comprise a single board computer supplemented with add-on circuit boards that interface with the sensors 12, the airflow distribution balancer 14, the airflow generator 16, and any other components as needed.

[0054] Sensor The one or more sensors 12 include at least one pressure sensor 18 for sensing pressure inside and outside the enclosed space S or inside the enclosed space S, at least one dust sensor 20 for sensing the presence of dust particles in the enclosed space S, at least one CO2 sensor 22 for sensing the presence of CO2 in the enclosed space S, at least one airflow sensor 24 for sensing airflow, and / or one or more gas sensors 26 for sensing the presence of other gases. The dust sensor 20, the CO2 sensor 22, and the gas sensor 26 can sense the presence of dust particles, CO2, and other gases by detecting concentrations of the dust particles, CO2, and other gases, respectively, that exceed their respective minimum threshold concentrations.

[0055] The controller 11 is in operative communication with each of the pressure sensor 18, the dust sensor 20, the CO2 sensor 22, the air flow sensor 24 and the gas sensor 26 such that the controller 11 can receive one or more input signals from the pressure sensor 18, the dust sensor 20, the CO2 sensor 22, the air flow sensor 24 and the gas sensor 26.

[0056] To sense the pressure inside and outside the enclosed space S, or inside the enclosed space S, one or more pressure sensors 18 are provided. The dust sensor 20 may also be referred to by other terms, such as a particulate mass sensor or PM sensor. One or more dust sensors 20 are provided to sense the concentration of dust particles within the enclosed space S. However, one or more dust sensors 20 may also be provided outside the enclosed space S, i.e., external dust sensors 20. Such external dust sensors 20 enable the controller 11 to determine a protection factor. For example, with respect to a protection factor provided in relation to a dust level, the protection factor may be calculated by dividing the inside dust concentration (sensed by the dust sensor 20 inside the enclosed space S) by the outside dust concentration (sensed by the dust sensor 20 outside the enclosed space S). For example, when the internal dust sensor 20 detects that the dust concentration within the enclosed space S is 10 ppm (parts per million), the protection factor may be calculated by dividing the inside dust concentration (sensed by the dust sensor 20 outside the enclosed space S). 3) and the external dust sensor 20 indicates that the dust concentration outside the closed space S is 10,000 ppm, the protection factor is calculated by dividing the inside count by the outside count, i.e., 10,000 ÷ 10 = 1,000, resulting in a protection factor of 1,000.

[0057] To sense the concentration of CO2 within the enclosed space S, one or more CO2 sensors 22 are provided. The airflow sensors 24 sense the airflow at each location where they are provided. In the installation of system 1 shown in FIG. 1A, airflow sensors 24 are provided at various locations. A first airflow sensor 24 is located before (i.e., upstream of) the airflow distribution balancer 14 to sense the airflow of fresh air flow F. A second airflow sensor 24 is located before (i.e., upstream of) the airflow distribution balancer 14 and after (i.e., downstream of) the enclosed space S to sense the airflow of recirculated air flow R. A third airflow sensor 24 is located near an air outlet unit U of the HVAC system to sense the airflow of single air flow A into the enclosed space S.

[0058] Airflow sensor 24 may be a mass airflow sensor that senses the amount of airflow. One or more gas sensors 26 are provided to sense the concentration of gases within the enclosed space S. These are gases other than CO that may be undesirable to be present within the enclosed space S. Such other gases may include, for example, hydrogen sulfide (H2S), sulfur dioxide (SO2), and / or refrigerant gases such as, for example, R-1234YF.

[0059] At least some of the sensors 12 may be mounted in one or more sensor pods 28. For example, in Figure 1A, pressure sensor 18, dust sensor 20, CO2 sensor 22, and gas sensor 26 are shown as being mounted in sensor pod 28.

[0060] Air Flow Distribution Balancer - First Embodiment 12 to 19 show a first embodiment of the air flow distribution balancer 14. FIG. The air flow distribution balancer 14 includes a casing 40 having a first inlet 42 , a second inlet 44 , at least one outlet 46 , and at least one door 48 .

[0061] The first inlet 42 and the second inlet 44 are substantially the same size. The casing 40 has a first end 50 and a second end 51. The first inlet 42 and the second inlet 44 are disposed at the first end 50 of the casing 40. At least one outlet 46 is disposed at the second end 51 of the casing 40. The casing 40 encloses a chamber 52. The first inlet 42 and the second inlet 44 are in fluid communication with the chamber 52. A door 48 is disposed inside the chamber 52. The door 48 is disposed adjacent to the first inlet 42 and the second inlet 44.

[0062] The casing 40 comprises two parts 40a and 40b. In Figures 12-16, the casing part 40a is on the upper side and the casing part 40b is on the lower side. The two casing parts 40a and 40b may be connected to each other by a bolt (not shown) that passes through the lugs 54a and 54b of the casing parts 40a and 40b, respectively. In Figures 14, 15, and 16, the air flow distribution balancer 14 is shown with the casing part 40a removed to show the interior of the air flow distribution balancer 14.

[0063] At least one door 48 is movable to a selected position. In the first position of the door 48, the door 48 closes the first entrance 42. In the first position of the door 48, the door 48 does not close the second entrance 44. In the second position of the door 48, the door 48 closes the second entrance 44. In the second position of the door 48, the door 48 does not close the first entrance 42.

[0064] In the first position of the door 48, the first entrance 42 is closed and the second entrance 44 is open. The door 48 is shown in the first position in Figures 13 and 14. Figures 13 and 14 show that in the first position, the door 48 completely blocks the first entrance 42 (so that the first entrance 42 is completely closed) and does not block the second entrance 44 (so that the second entrance 44 is completely open). In the second position of the door 48, the first entrance 42 is closed and the second entrance 44 is open. The door 48 is shown in the second position in Figures 12 and 15. Figures 12 and 15 show that in the second position, the door 48 completely blocks the second entrance 44 (so that the second entrance 44 is completely closed) and does not block any portion of the first entrance 42 (so that the first entrance 42 is completely open).

[0065] Because the first inlet 42 and the second inlet 44 are substantially the same size, the cross-sectional area of ​​the first inlet 42 is the same as the cross-sectional area of ​​the second inlet 44 when fully open. The door 48 is movable to a selected position between a first position and a second position. The selected position can be the first position, the second position, or an intermediate position between the first and second positions. FIG. 16 shows the door 48 in an intermediate position between the first and second positions. In the intermediate position of the door 48, the first entrance 42 and the second entrance 44 are partially open and partially closed. In the intermediate position of the door 48 shown in FIG. 16, the first entrance 42 and the second entrance 44 are partially open and partially closed to the same extent. That is, the size of the opening of the first entrance 42 and the size of the opening of the second entrance 44 are equal. Similarly, in the intermediate position of the door 48 shown in FIG. 16, the size of the opening of the first entrance 42 and the second entrance 44 are equal.

[0066] In other intermediate positions of the door 48 (i.e., intermediate positions other than the intermediate position shown in FIG. 16 ), one of the first entrance 42 and the second entrance 44 is more open and the other is more closed. The degree to which the first entrance 42 and the second entrance 44 are open or closed is determined by the relative positions of the door 48. The closer the door 48 is to the first position, the more the second entrance 44 is open. In addition, the more the first entrance 42 is closed. Conversely, the closer the door 48 is to the second position, the more the first entrance 42 is open. In addition, the more the second entrance 44 is closed. Therefore, when the door 48 is moved to increase the opening of the first entrance 42, the opening of the second entrance 44 is closed further in inverse proportion, and when the door 48 is moved to decrease the opening of the first entrance 42 (i.e., close the opening of the first entrance 42 further), the opening of the second entrance 44 is increased in inverse proportion.

[0067] The door 48 includes a plate 56. The plate 56 has a first side 58 and a second side. The second side is opposite the first side 58 and is therefore not visible in the drawings. The first side 58 faces the first inlet 42 and the second inlet 44. The second side of the plate 56 faces the chamber 52 inside the casing 40. The door 48 further includes a first end plate 60 and a second end plate 62. The first end plate 60 and the second end plate 62 are provided on opposite ends of the plate 56. The first end plate 60 and the second end plate 62 extend from each end of the plate 56 into the chamber 52.

[0068] The profile of the plate 56 is formed to match the profile of the interior surface of the casing 40 surrounding the first and second entrances 42, 44 at the first end 50 of the casing 40. This matching profile minimizes the gap between the plate 56 and the interior surface of the casing 40 as the door moves between the first and second positions.

[0069] The contours of the first and second end plates 60, 62 are formed to match the interior surfaces of the sides of the casing 40 adjacent the first and second entrances 42, 44. This matching contour minimizes gaps between the first and second end plates 60, 62, respectively, and the interior surfaces of the casing 40 when the door 48 is in the first and second positions.

[0070] One or more arms 66 extend from the door 48. The one or more arms 66 extend from the plate 56 of the door 48. The one or more arms 66 extend to a rod 68. The one or more arms 66 connect the door 48 to the rod 68. A portion of the rod 68 is received in a sleeve 69. The sleeve 69 has a bore 69a. The bore 69a extends axially through the sleeve 69. A portion of the rod 68 is received in the bore 69a. That portion of the rod 68 is received in the bore 69a via a first end of the bore 69a. The rod 68 is fastened to the sleeve 69, for example, by a screw that passes through an opening in the sleeve 69 and firmly abuts the rod 68. The rod 68 and the sleeve 69 are fastened so that they cannot move relative to each other.

[0071] The air flow distribution balancer 14 further includes a motor 70. The door 48 and the motor 70 are operatively connected such that the motor 70 is operable to move the door 48. The motor 70 is operable to move the door 48 to a selected position. The selected position may be a first position, a second position, or any intermediate position between the first and second positions.

[0072] The motor 70 is disposed within a housing 72. The motor 70 is best seen in FIGS. 18 and 19. The housing 72 is best seen in FIG. 17. The housing 72 is attached to the casing 40. The housing 72 is attached to the casing part 40b. The housing 72 is external to the chamber 52. The motor 70 has a rotatable shaft 74. Operation of the motor 70 rotates the shaft 74. A portion of the shaft 74 is received within the bore 69a of the sleeve 69. This portion of the shaft 74 is received within the bore 69a via the second end of the bore 69a. The shaft 74 is fastened to the sleeve 69. For example, the shaft 74 may be fastened to the sleeve 69 by a screw that passes through an opening in the sleeve 69 and firmly abuts the shaft 74. The shaft 74 and the sleeve 69 are fastened so that they cannot move relative to each other. Thus, both the rod 68 and the shaft 74 are fastened to the sleeve 69. The sleeve 69 is movable in a rotational manner with the shaft 74. The rod 68 is movable in a rotational manner with the shaft 74. The motor 70 is operable to rotate the shaft 74 so that the door 48 can be moved between a first position and a second position, thereby positioning the door at a selected position from the first position to the second position and any intermediate position therebetween. Specifically, the shaft 74 is rotatable in an oscillating manner. The oscillating rotation of the shaft 74 is a reciprocating rotation, i.e., a rotation in a first direction through a limited angular arc and then a rotation in the opposite direction. The limited angular arc corresponds to the first and second positions of the door 48. Thus, the shaft 74 does not rotate 360°.

[0073] The casing 40 includes first and second tubular portions 76 at the first end 50 of the casing 40. The first and second tubular portions 76 form the first inlet 42 and the second inlet 44. The tubular portions 76 are substantially the same size. Because the first and second tubular portions 76 are substantially the same size, the tubular portions 76 have substantially the same cross-sectional area.

[0074] In the first position of the door 48, the plate 56 completely blocks the first entrance 42, thereby completely blocking the first entrance 42. In the second position of the door 48, the plate 56 completely blocks the second entrance 44, thereby completely blocking the second entrance 44. When the door 48 is in an intermediate position (i.e., a position between, but not between, the first and second positions of the door 48), each of the first entrance 42 and the second entrance 44 is partially open and partially closed. In such an intermediate position of the door 48, the plate 56 partially blocks each of the first entrance 42 and the second entrance 44. The extent to which the plate 56 blocks the first entrance 42 and the second entrance 44 depends on the relative positions of the door 48, as discussed above in reference to the degree to which the first entrance 42 and the second entrance 44 are open and closed.

[0075] The air flow distribution balancer 14 may be used in the system 1 shown in FIG. 1A. The fresh air flow F may be received at a first inlet 42 of the air flow distribution balancer 14, and the recirculated air flow R may be received at a second inlet 44 of the air flow distribution balancer 14. However, the first inlet 42 and the second inlet 44 may receive either of the two air flows F and R. Thus, the roles of the first inlet 42 and the second inlet 44 may be reversed, with the recirculated air flow R being received at the first inlet 42 and the fresh air flow F being received at the second inlet 44.

[0076] The door 48 may be used to adjust the amount or volume of fresh air and recirculated air that is admitted to the air flow distribution balancer 14. In that regard, the position of the door 48 affects the amount or volume of fresh air and recirculated air that is admitted to the air flow distribution balancer 14. Moving the door 48 away from the first position to an intermediate position closer to the second position increases the size of the opening of the first inlet 42 and decreases the size of the opening of the second inlet 44. Assuming no change in the velocity of the fresh air flow F or the recirculated air flow R, this results in a greater volume of fresh air and a smaller volume of recirculated air that can enter the air flow distribution balancer 14 and enter the chamber 52. Conversely, moving the door 48 away from the second position to an intermediate position closer to the first position increases the size of the opening of the second inlet 44 and decreases the size of the opening of the first inlet 42. Assuming there is no change in the velocities of the fresh air flow F and the recirculated air flow R, the result is a larger volume of recirculated air and a smaller volume of fresh air that can enter the air flow distribution balancer 14 and enter the chamber 52.

[0077] When the door 48 is in the first position, the first inlet 42 (for the fresh air flow F) is fully closed and the second inlet 44 (for the recirculated air flow R) is fully open. When the door 48 is in the first position, only recirculated air can enter the air flow distribution balancer 14, into the chamber 52 (through the fully open second inlet 44) and out the outlet 46.

[0078] When the door 48 is in the second position, the first inlet 42 (for the fresh air flow F) is fully open and the second inlet 44 (for the recirculated air flow R) is fully closed. When the door 48 is in the second position, only fresh air can enter the air flow distribution balancer 14, enter the chamber 52 (through the fully open first inlet 42) and exit through the outlet 46.

[0079] When the door 48 is in an intermediate position (i.e., between the first and second positions), both the first inlet 42 (for fresh air flow F) and the second inlet 44 (for recirculated air flow R) are partially open (and partially closed). When the door 48 is in the intermediate position, both fresh air and recirculated air can enter the chamber 52 of the air flow distribution balancer 14 (through the partially open first inlet 42 and second inlet 44).

[0080] The fresh air and recirculated air mix within chamber 52 and exit outlet 46 as a single air flow A (i.e., exit air flow). Thus, single air flow A is a composite air flow made up of the air in fresh air flow F and the air in recirculated air flow R entering air flow distribution balancer 14. The relative sizes of the sub-openings of first inlet 42 and second inlet 44 affect the volume of fresh air and recirculated air that can enter air flow distribution balancer 14 and enter chamber 52, as previously described herein.

[0081] Thus, the door 48 can be moved to a selected position to adjust the airflow ratio between the fresh air flow F and the recirculated air flow R. Air Distribution Balancer - Second Embodiment 20 shows a second embodiment of the airflow distribution balancer 14a. The airflow distribution balancer 14a of the second embodiment is similar to the airflow distribution balancer 14 of the first embodiment, but the sizes of the first inlet 42a and the second inlet 44a of the airflow distribution balancer 14a are different. Therefore, the cross-sectional areas of the first inlet 42a and the second inlet 44a are different from each other.

[0082] Specifically, in the embodiment shown in Figure 20, the second inlet 44a is larger than the first inlet 42a, i.e., the first inlet 42a is smaller than the second inlet 44a. Because the second inlet 44a is larger than the first inlet 42a, the cross-sectional area of ​​the second inlet 44a is larger than the cross-sectional area of ​​the first inlet 42a. The tubular portion 76aa of the second inlet 44a is larger than the tubular portion 76a of the first inlet 42a. Therefore, the cross-sectional area of ​​the tubular portion 76aa is larger than the cross-sectional area of ​​the tubular portion 76a.

[0083] Thus, a greater volume of air is admitted into chamber 52 through second inlet 44a and tubular portion 76aa than through first inlet 42a and tubular portion 76a.

[0084] The air flow distribution balancer 14a may be used in the system 1 shown in FIG. 1A. When fresh air flow F is received at the first inlet 42a and recirculated air flow R is received at the second inlet 44a, because the second inlet 44a is larger than the first inlet 42a, the airflow of the recirculated air flow R into the airflow distribution balancer 14a is increased relative to the airflow of the fresh air flow F. This allows the recirculated airflow into the airflow distribution balancer 14a to be increased while maintaining the fresh air flow into the airflow distribution balancer 14a at a desired level. Thus, in contrast to the airflow distribution balancer 14 of the first embodiment, moving the door 48 does not proportionally change the amount or volume of fresh air and recirculated air entering the airflow distribution balancer 14a and entering the chamber 52.

[0085] In FIG. 20 , the second inlet 44a is shown as being larger than the first inlet 42a. However, alternatively, the first inlet 42a may be larger than the second inlet 44a. The relative sizes of the first inlet 42a and the second inlet 44a may be proportional. For example, the second inlet 44a may have a cross-sectional area twice that of the first inlet 42a. In such a configuration, the amount or volume of recirculated air that can flow into the air flow distribution balancer 14 is twice the amount or volume of fresh air that can flow into the air flow distribution balancer 14. Other ratios may be achieved by appropriately adjusting the relative cross-sectional sizes of the first inlet 42a and the second inlet 44a.

[0086] Additionally, similar to the air flow distribution balancer 14 of the first embodiment, either the first inlet 42a or the second inlet 44a of the air flow distribution balancer 14a may receive either one of the two air flows F and R. Thus, if it is desired to increase the air flow of the fresh air flow F into the air flow distribution balancer 14a relative to the air flow of the recirculated air flow R, the fresh air flow F is directed to the larger of the first inlet 42a or the second inlet 44a, and the recirculated air flow R is directed to the other inlet.

[0087] In other respects, the second embodiment air flow distribution balancer 14a and its use in the system 1 shown in FIG. 1A is similar to the first embodiment air flow distribution balancer 14. Air Flow Distribution Balancer - Third Embodiment 21 to 24 show a third embodiment of the air flow distribution balancer 14b.

[0088] The air flow distribution balancer 14b of the third embodiment is similar to the air flow distribution balancer 14 of the first embodiment, except that the air flow distribution balancer 14b includes two doors 48b and two motors 70. Each door 48b is associated with a respective inlet 42. Each motor 70 is disposed within a respective housing 72b. The doors 48b of the air flow distribution balancer 14b of the third embodiment are different from the doors 48 of the air flow distribution balancer 48 of the first embodiment.

[0089] Each door 48b is movable to a selected position. In the first position of the door 48b, the door 48b closes the respective entrance 42 or 44. In the second position of each door 48b, the door 48b closes the respective entrance 42 or 44.

[0090] Respective doors 48b are provided for the first entrance 42 and the second entrance 44. In a first position of the door 48b for the first entrance 42, the door 48b closes the first entrance 42 (i.e., the first entrance 42 is closed). In a second position of the door 48b for the first entrance 42, the door 48b does not close the first entrance 42 (i.e., the first entrance 42 is open). In a first position of the door 48b for the second entrance 44, the door 48b closes the second entrance 44 (i.e., the second entrance 44 is closed). In a second position of the door 48b for the second entrance 44, the door 48b does not close the second entrance 44 (i.e., the second entrance 44 is open).

[0091] In FIG. 21, both doors 48b (of the first entrance 42 and the second entrance 44) are shown in their respective first positions. FIG. 21 shows that in their respective first positions, the doors 48b completely block their respective first entrance 42 and second entrance 44 (thus, the first entrance 42 and second entrance 44 are completely closed). In FIG. 22, both doors 48b are shown in their respective second positions. FIG. 22 shows that in their respective second positions, the doors 48b do not block their respective first entrance 42 and second entrance 44 (thus, the first entrance 42 and second entrance 44 are completely open). In FIG. 23, the door 48b of the first entrance 42 is shown in its first position (i.e., closed), and the door 48b of the second entrance 44 is shown in its second position (i.e., open).

[0092] Each door 48b is movable to a selected position between a first position and a second position. The selected position can be the first position, the second position, or an intermediate position between the first and second positions. Each door 48b is operably connected to a respective motor 70 such that the motor 70 is operable to move the respective door 48b. The respective motor 70 is operable to move the respective door 48b to the selected position. Each door 48b is movable by the respective motor 70 independently of the other door 48b.

[0093] Each door 48b is movable to an intermediate position between a first position and a second position, in which the corresponding first entrance 42 or second entrance 44 is partially open and partially closed.

[0094] When the door 48b is in an intermediate position, the degree to which the corresponding first entrance 42 or second entrance 44 is open or closed is determined by the relative position of the door 48b. Thus, the closer the door 48b is to the first position, the greater the degree to which the corresponding first entrance 42 or second entrance 44 is closed. Conversely, the closer the door 48b is to the second position, the greater the degree to which the corresponding first entrance 42 or second entrance 44 is open.

[0095] Each door 48b includes a plate 56b. The plate 56b has a first side 58b and a second side. The second side is opposite the first side 58b. Therefore, the second side is not visible in the drawings. When the door 48b closes the corresponding first inlet 42 or second inlet 44, the first side 58b of the plate 56b faces the corresponding first inlet 42 or second inlet 44, and the second side of the plate 56b faces the chamber 52 within the casing 40.

[0096] Each door 48b has a bore 78 extending therethrough. The bore 78 is centrally located within each door 48b. The bore 78 is located along a line that follows the diameter of each door 48b. A shaft 74 of the motor 70 is received in the bore 78 of the respective door 48b. The doors 48b do not rotate relative to their respective shafts 74; rather, the doors 48b rotate with their respective shafts 74.

[0097] The motor 70 is operable to rotate the shaft 74 so that each door 48b can be moved between a first position and a second position, thereby positioning the door at a selected position from the first position to the second position and any intermediate position therebetween. For example, each door 48b may be rotatable in a swinging manner. Moving the door 48b in a swinging manner is achieved by the shaft 74 moving in a swinging rotational manner. The swinging rotation of the shaft 74 is a reciprocating rotation, i.e., a rotation in a first direction through a limited angular arc and then a rotation in the opposite direction. The limited angular arc corresponds to the first and second positions of the door 48b. The limited angular arc may be 90°.

[0098] The housing 72b is attached to the casing 40. The housing 72b is attached to the casing part 40b. The housing 72b is attached to each tubular section 76. A door 48b is disposed in each section 76.

[0099] In an alternative embodiment (not shown), motor 70 may be provided in a single housing instead of two separate respective housings 72b. In such an embodiment, the single housing is attached to casing 40. The single housing is attached to casing part 40b. The single housing is attached to tubular portion 76.

[0100] The air flow distribution balancer 14b may be used in the system 1 shown in FIG. 1A. The use and operation of the air flow distribution balancer 14b of the third embodiment is similar to the use and operation of the air flow distribution balancer 14 of the first embodiment, except that each door 48b is independently movable under the operation of its respective motor 70.

[0101] Thus, the fresh air flow F may be received at a first inlet 42 of the air flow distribution balancer 14b. The recirculated air flow R may be received at a second inlet 44 of the air flow distribution balancer 14b. Alternatively, the recirculated air flow R is received at the first inlet 42 and the fresh air flow F is received at the second inlet 44.

[0102] The door 48b may be used to independently adjust the amount or volume of fresh air and recirculated air admitted to the airflow distribution balancer 14b. In that regard, the position of the door 48b affects the amount or volume of fresh air and recirculated air admitted to the airflow distribution balancer 14b. Moving the door 48b away from the first position to an intermediate position closer to the second position increases the size of the opening of the corresponding inlet (i.e., the first inlet 42 or the second inlet 44). Assuming no change in the velocity of the airflow (i.e., the fresh air flow F or the recirculated air flow R) directed at the inlet, increasing the size of the opening of the corresponding inlet increases the volume of air (i.e., the fresh air or the recirculated air, depending on which airflow is connected to the inlet) that can enter the chamber 52. Conversely, moving the door 48b away from the second position to an intermediate position closer to the first position decreases the size of the opening of the corresponding inlet. Assuming there is no change in the velocity of the airflow directed at an inlet, a reduction in the size of the corresponding inlet opening reduces the volume of air (i.e., fresh air or recirculated air, depending on which airflow is connected to the inlet) that can enter chamber 52.

[0103] Assuming that the first inlet 42 receives a fresh air flow F and the second inlet 44 receives a recirculated air flow R, when the door 48b of the first inlet 42 is in the first position, the first inlet 42 is fully closed. Conversely, when the door 48b of the first inlet 42 is in the second position, the first inlet 42 is fully open, thereby allowing a maximum flow rate of fresh air flow F to flow through the first inlet 42 and into the chamber 52 within the air flow distribution balancer 14b. Similarly, when the door 48b of the second inlet 44 is in the first position, the second inlet 44 is fully closed. Conversely, when the door 48b of the second inlet 44 is in the second position, the second inlet 44 is fully open, thereby allowing a maximum flow rate of recirculated air flow R to flow through the second inlet 44 and into the chamber 52 within the air flow distribution balancer 14b.

[0104] When the door 48b of the first inlet 42 (for fresh air flow F) is in the intermediate position, the flow of fresh air flow F (through the partially open first inlet 42) into the chamber 52 within the air flow distribution balancer 14b is less than the maximum flow rate when the door 48b is in the second position. Similarly, when the door 48b of the second inlet 44 (for recirculated air flow R) is in the intermediate position, the flow of recirculated air flow R (through the partially open second inlet 44) into the chamber 52 within the air flow distribution balancer 14b is less than the maximum flow rate when the door 48b is in the second position.

[0105] The fresh air and recirculated air mix within chamber 52 and exit outlet 46 as a single air stream A. The relative sizes of the openings of first inlet 42 and second inlet 44 affect the volume of fresh air and recirculated air that can enter air flow distribution balancer 14 and enter chamber 52, as previously described herein.

[0106] Thus, each of the doors 48b can be moved to a selected position to adjust the flow of fresh air flow F and recirculated air flow R entering the chamber 52 of the air flow distribution balancer 14b through the first inlet 42 and the second inlet 44, respectively.

[0107] Because the doors 48b are independently movable from one another, a greater degree of control is provided over the amount or volume of fresh and recirculated air that can flow into the chamber 52 in the air flow distribution balancer 14b than is possible with an air flow distribution balancer that uses only a single door 48. Thus, two separate, independently movable doors (one for each inlet 42 / 44) for controlling the fresh air flow F and the recirculated air flow R, respectively, allow for independent control of the fresh air flow F and the recirculated air flow R.

[0108] In other respects, the third embodiment air flow distribution balancer 14b and its use in the system 1 shown in FIG. 1A is similar to the first embodiment air flow distribution balancer 14. Air Flow Distribution Balancer - Fourth Embodiment A fourth embodiment of the air flow distribution balancer (not shown) has two doors 48b and two motors 70 (similar to the third embodiment of the air flow distribution balancer 14b) and has first and second inlets 42a and 44a of different sizes (similar to the second embodiment of the air flow distribution balancer 14a).

[0109] In other respects, the fourth embodiment air flow distribution balancer and its use in the system 1 shown in FIG. 1A is similar to the first, second and third embodiment air flow distribution balancers 14, 14a and 14b.

[0110] Air flow generator - first embodiment The air flow generator 16 in the system 1 shown in Figure 1A is provided in the form of an air compressor 16. Air compressors are known in the art.

[0111] An air flow generator 16 in the form of an air compressor 16 generates a fresh air flow F. An air flow generator 16 in the form of an air compressor 16 generates a recirculated air flow R. The air compressor 16 includes an inlet 29 for air drawn into the air compressor 16 and an outlet 30 for air exiting the air compressor 16. An air flow path is provided inside the air compressor 16 from the inlet 29 to the outlet 30. The air compressor 16 further includes a motor and a fan or impeller (or similar device) in the flow path within the air compressor 16. The fan or impeller is driven by the motor. The motor is located inside the air compressor 16. The motor drives the fan or impeller, which generates a fresh air flow F and a recirculated air flow R. The fresh air flow F and the recirculated air flow R thereby flow to and through the air flow distribution balancer 14 and the air compressor 16, and exit the air flow distribution balancer 14 as air flow A.

[0112] Some air pressurizers may further include a filter. In this embodiment of system 1, air pressurizer 16 does not have a filter. However, the air entering air pressurizer 16 from the fresh air flow F typically includes dust particles present in the ambient environment in which the vehicle in which system 1 is installed operates. For such environments, as described further herein, system 1 further includes one or more filters for filtering dust particles from the fresh air flow F before the air is delivered into enclosed space S. If system 1 operates in an environment in which dust particles are not present, the filter may be omitted from system 1, i.e., a filterless pressurizer may be used, and a separate filter is not required. However, system 1 is typically expected to operate in an environment in which dust particles are present, and therefore system 1 includes a filter. In any event, as a precaution, system 1 typically includes a filter regardless of the environment in which system 1 operates. As described above, some air pressurizers may include a filter. An embodiment of a system (2) having an air compressor (16a) equipped with a filter (31) for filtering dust particles is described herein with reference to FIG. 2. The filter is located inside the air compressor 16. In that regard, air entering the air compressor 16 from the fresh air flow F is likely to contain dust particles due to the ambient environment in which the vehicle in which the system 1 is installed operates. Meanwhile, air entering the air compressor 16 from the recirculated air flow R has previously passed through a filter. Air drawn into the air compressor 16 passes through a filter within the air compressor 16. The filter filters out dust particles. Depending on the type and rating of the filter, the filter may also filter out other contaminants (e.g., undesirable gases). The filtered air then exits the air compressor 16 through an outlet 30. The filtered air is then directed into the enclosed space S.

[0113] Other components of the system Other components of System 1 are described in the following sections. filter As described above, the air compressor 16 is not provided with a filter for filtering dust particles. Therefore, the system 1 may further include one or more filters 31. Such filters 31 are separate from the air compressor 16. The filter 31 is provided upstream of the HVAC system of the vehicle in which the system 1 is installed. The filter 31 is provided upstream of the enclosed space S. In the system 1 (shown in FIG. 1), the filter 31 is provided downstream of the outlet 30 of the air compressor 16. In the system 1 (shown in FIG. 1), the filter 31 is provided upstream of the enclosed space S and the HVAC system of the vehicle in which the system 1 is installed. The filter 31 shown in FIG. 1 may include, for example, a fine particle filter. The fine particle filter is provided to filter dust particles. The dust particles that the filter 31 can filter can include particles with particle sizes up to fine particles. The fine particle filter of the filter 31 may include, for example, a HEPA filter, a ULPA filter, an EPA filter, or another filter capable of filtering fine particles.

[0114] However, the filter 31 may comprise other types of filters. For example, a fine particle filter may be provided to filter dust particles from the air, followed by an activated carbon filter to filter undesirable gases, so as to also filter undesirable gases from the air. Another fine particle filter may be provided after the activated carbon filter as an additional safety margin. The inclusion of an additional filter 31 is shown in FIG. 1B and described further herein. The type of filter selected for use as the one or more filters 31 depends on the type of contaminants in the work environment in which the vehicle (having the enclosed space S) is operated.

[0115] Air is directed in only one direction through the filter 31. The filter may therefore be a directional filter. Air Precleaner System 1 may further include an air precleaner 32. The air precleaner 32 is desirable when the ambient environment outside the enclosed space S into which fresh air is drawn has an undesirable concentration of large, heavy dust particles. The air precleaner 32 is provided to remove the largest and heaviest dust particles from the ambient air (outside the enclosed space) before the air is directed to other components of system 1. The air precleaner 32 is best shown in FIG. 3. The air precleaner 32 includes an inlet and an outlet. The outlet of the air precleaner 32 is connected to a first inlet 42 of the air flow distribution balancer 14. The first inlet 42 receives the fresh air flow F. Ambient air (from outside the enclosed space S) is drawn into the air precleaner 32 through the inlet of the air precleaner 32. The largest and heaviest dust particles in the ambient air drawn into the air precleaner 32 are discharged through one or more exhaust ports of the air precleaner 32. The ambient air (with the heaviest dust particles removed) then flows through the air precleaner 32 to the outlet of the air precleaner 32. This air flow is the fresh air flow F, as shown in Figure 3. From the outlet of the air precleaner 32, the fresh air flow F flows through the first inlet 42 and into the chamber 52 of the air flow distribution balancer 14.

[0116] Air is drawn into the air precleaner 32 under the action of the fan or impeller of the air compressor 16. In this manner, the air compressor 16 produces a fresh air flow F. The air precleaner may be, for example, an air intake cleaning device of the type disclosed in US Pat. No. 6,361,574.

[0117] If the precleaner 32 is not required, external air may be drawn directly as fresh air flow F into the first inlet 42 of the air flow distribution balancer 14 . Duct piping The system 1 further comprises ducts for the passage of various air flows through the system 1 .

[0118] In the installation shown in Figure 1A, as best seen in Figures 2 and 3, a first duct 33a extends from the outlet 46 of the air flow distribution balancer 14 to the inlet 29 of the air compressor 16. A second duct 33b extends from the outlet 30 of the air compressor 16 to an air outlet unit U of the HVAC system. An opening is formed in the shell H of the cabin C for duct 33b, which opening is generally indicated by the reference numeral 35a in Figure 2. A third duct 33c extends from the return air unit N to the second inlet 44 of the air flow distribution balancer 14. An opening 35b is formed in the shell H of the cabin C for duct 33c, which is best seen in Figures 10 and 11.

[0119] A single air flow A can flow in a second duct 33a from the air flow distribution balancer 14 to the air compressor 16, and after filtering in the air compressor 16, flows in a second duct 33b from the air compressor 16 to the HVAC system air outlet unit U. A recirculated air flow R can flow in a third duct 33c from the return air unit N to the air flow distribution balancer 14.

[0120] interface Optionally, the system 1 may further include one or more interfaces with the controller 11. By way of example, three different types of interfaces are described herein. A first interface may include a user interface with the controller 11. The first interface allows a user, such as an operator located within the enclosed space S, to interact with the controller 11. A second interface may include a web interface. The system 1 may have a built-in Wi-Fi network, and the web interface allows a user to connect to the controller 11 via the built-in Wi-Fi network using an appropriate device, such as a (laptop) computer or smartphone. The system may also be equipped with Long Term Evolution (LTE) support. As an alternative to or in addition to the system 1 having a built-in Wi-Fi network, the controller 11 may be connectable to an external network via Wi-Fi, Ethernet, and / or USB interfaces. For example, the system may interface with a USB LTE adapter to connect to an external network. A third type of interface may include an interface between the system 1 and an OEM system. This third type of interface may be necessary, for example, when the enclosed space S (or another device with which the enclosed space S is associated, such as a vehicle) has an OEM system that is desired to interface with system 1.

[0121] The drawings show the first type of interface mentioned above. This user interface 34 is connected to the controller 11. The user interface 34 may be physically separate from the controller 11. The user interface 34 may comprise a circuit board. The user interface 34 may comprise a microcontroller. The user interface 34 may further comprise a housing for a keypad and a display. The display may be a backlit display. However, a touch screen may be used instead of (or in addition to) a keyboard and display. The user interface 34 may be located in any suitable location, for example, within the enclosed space S. The user interface 34 may further comprise an alarm, for example, at least one of a buzzer and a warning light, to alert the operator to a situation requiring their attention.

[0122] Use and Operation: System - First Embodiment In the following description of the use and operation of system 1, the airflow distribution balancer is identified by the reference numeral "14#," indicating that, unless otherwise specified, a reference to airflow distribution balancer 14# may be any one of the first, second, third, or fourth embodiments described hereinabove.

[0123] In use, the air flow distribution balancer 14# receives a fresh air flow F from the air precleaner 32 (if provided) or directly from the ambient air outside the cabin C (if no air precleaner is provided), and a recirculated air flow R from the third duct 33c. The fresh air flow F and the recirculated air flow R enter the chamber 52 of the air flow distribution balancer 14# via the first inlet 42 / 42a and the second inlet 44 / 44a, respectively. The fresh air flow F and the recirculated air flow R are generated by the air compressor 16, as previously described herein. The fresh air and the recirculated air mix in the chamber 52. The combined fresh and recirculated air exits the casing 40 via the outlet 46 as a single air flow A. The single air flow A flows in the duct 33a to the air compressor 16. The single air stream A then flows from the air compressor 16 into a duct 33b, through a filter 31 (e.g., a fine particle filter, as described previously herein) in the duct 33b, and then to an air outlet unit U of the HVAC system. The air stream A is filtered as it flows through the filter 31. The single air stream A (comprising the filtered air) then passes through the air outlet unit U of the HVAC system. The HVAC system may apply selected temperature conditioning (i.e., heating or cooling) to the air as needed. The air is then discharged from the air outlet unit U of the HVAC system into the enclosed space S. The air outlet unit U of the HVAC system is typically equipped with a suitable blower (e.g., a fan or impeller) for discharging the air into the enclosed space S. The discharge of air from the air outlet unit U into the enclosed space S is indicated in FIG. 2 by reference numeral 36a. The discharged air 36a is the air in the single air stream A. Air from the enclosed space S is drawn into the return air unit N of the HVAC system by a blower B within the return air unit N. The air enters the return air unit N through an air inlet I, as shown by reference numeral 36b in FIG. 2. After entering through the air inlet I, the air flows through a filter T. The air then flows past the blower B and into duct 33c. The air flowing into duct 33c is the recirculated airflow R.The recirculated airflow R flows in duct 33c to airflow distribution balancer 14# and enters chamber 52 of airflow distribution balancer 14 via second inlet 44 / 44a.

[0124] The filters in system 1 (i.e., the filter in air compressor 16 and, if present, filter 31, such as a fine particle filter) are positioned within system 1 such that both fresh air stream F and recirculated air stream R flow through the filters before entering enclosed space S. In that regard, the air in fresh air stream F and the air from recirculated air stream R are combined within air flow distribution balancer 14# and exit air flow distribution balancer 14# through outlet 46 as a single air stream A. Thus, single air stream A includes both air from fresh air stream F and air from recirculated air stream R. After passing through outlet unit U of the HVAC system, single air stream A passes through the filter in air compressor 16 and any additional filters before entering the enclosed space. Fresh air stream F is drawn from ambient air in the typically dusty environment outside enclosed space S and cabin C, and therefore is an air stream that is more loaded with contaminants, such as dust particles. However, the recirculated air flow R leaving the enclosed space S via the third duct 33c may also contain dust particles from the enclosed space S, although in less amount than would typically be contained in the fresh air flow F. In that regard, dust particles may enter the enclosed space S, for example through gaps in the sealing devices of the cabin C if a door or window of the cabin C is open, or by falling off the clothing of personnel entering the enclosed space S. It is therefore advantageous to filter the air in the recirculated air flow R flowing from the enclosed space S before returning it to the enclosed space S in a single air flow A, so that any dust particles from the enclosed space S that are in the recirculated air flow R are removed by the filter.

[0125] As described herein above, system 1 includes one or more sensors 12 of the type described above. Controller 11 receives input signals from each of sensors 12 in system 1 that sense a particular environmental parameter indicative of the air quality within enclosed space S, e.g., air differential pressure, dust level / concentration, etc. These input signals are indicative of the respective environmental parameter sensed by the sensor. In response to the input signals from sensors 12, controller 11 generates output signals that are transmitted to the motor of air compressor 16 and / or motor 70 of air flow distribution balancer 14#.

[0126] The output signal generated by the controller 11 and sent to the motor of the air compressor 16 causes the motor to adjust its speed if the input signal issued by the sensor 12 and received by the controller 11 indicates that the corresponding environmental parameter is not at a desired level, i.e., a predetermined value (which may include being above or below the predetermined value, depending on the environmental parameter being monitored), or is not within a predetermined range of values. Adjusting the speed involves increasing or decreasing the speed of the motor, which in turn increases or decreases the rotational speed of the fan or impeller within the air compressor 16. Increasing the rotational speed of the fan or impeller within the air compressor 16 correspondingly increases the fresh air flow F and recirculated air flow R drawn into the air flow distribution balancer 14#, thereby increasing the single air flow A flowing from the outlet 46 of the air flow distribution balancer 14# into the air compressor 16. Conversely, reducing the rotational speed of the fan or impeller within the air compressor 16 results in a corresponding reduction in the fresh air flow F and recirculated air flow R drawn into the air flow distribution balancer 14#, resulting in a reduction in the single air flow A flowing from the outlet 46 of the air flow distribution balancer 14# into the air compressor 16.

[0127] If the input signal issued by the sensor 12 and received by the controller 11 indicates that the corresponding environmental parameter is at a predetermined value or within a predetermined range of values, the output signal sent from the controller 11 to the motor of the air compressor 16 does not cause any adjustment of the speed of the motor, i.e., the speed of the motor remains unchanged (i.e., is not adjusted), and therefore the rotational speed of the fan or impeller in the air compressor 16 also does not change (i.e., is not adjusted).

[0128] The output signal generated by controller 11 and sent to motor 70 of airflow distribution balancer 14# causes motor 70 to move door 48 / 48b of airflow distribution balancer 14# when the input signal issued by sensor 12 and received by controller 11 indicates that an adjustment in the amount or volume of fresh air and / or recirculated air received within enclosed space S is necessary, i.e., when the amount or volume of fresh air and recirculated air supplied to enclosed space S needs to be rebalanced. This occurs when the input signal issued by sensor 12 and received by controller 11 indicates that the corresponding environmental parameter is not at a desired level, i.e., a predetermined value (which may include being above / below the predetermined value, depending on the environmental parameter being monitored), or is not within a predetermined range of values.

[0129] If the input signal issued by the sensor 12 and received by the controller 11 indicates that the corresponding environmental parameter is at a predetermined value or within a predetermined range of values, the output signal sent from the controller 11 to the motor 70 (which moves the door 48 / 48b) does not cause any change in the position of the door 48 / 48b, i.e., the position of the door 48 / 48b remains unchanged (i.e., is not adjusted).

[0130] Upon receiving an output signal from the controller 11 to adjust the speed, the motor of the air pressurizer 16 and / or the motor 70 of the air flow distribution balancer 14# (which moves the door 48 / 48b) changes the motor's operating target value to a higher or lower speed in accordance with the output signal received from the controller 11. However, if the output signal received by the motor from the controller 11 indicates that no adjustment to the speed of that motor is necessary, the speed of the motor remains unchanged (i.e., is not adjusted) in response to the output signal.

[0131] The normal condition of the system 1 (i.e., the system steady state condition) is when all sensors 12 sense that the monitored environmental parameters are at their respective predetermined values ​​or within predetermined ranges of values.

[0132] A normal condition (i.e., a parameter steady state condition) for a particular environmental parameter is when all sensors 12 monitoring the parameter sense that the particular environmental parameter is at its respective predetermined value or within a predetermined range of values.

[0133] The predetermined value or range of values ​​may be preselected to provide values ​​appropriate for the particular environmental parameter being monitored. For example, the preselection may be based on data obtained from a work safety agency.

[0134] The airflow distribution balancer 14# thus allows for the preparation of a mixture of fresh air F and recirculated air R to be continuously supplied to the enclosed space S. Adjustments to the airflow distribution balancer 14# (as previously described herein) and / or the speed of at least one of the airflow generator 16 and blower B allow for continuous, selective control of the air quality and pressure within the enclosed space S. The ratio (or relative amount) of fresh air and recirculated air delivered to the enclosed space S is controlled such that adjustments can be made in direct response to detected levels of monitored environmental parameters. These adjustments can be made in a continuous manner (i.e., continuously). Adjustment of the motor speed of the airflow generator 16 is used to adjust and control the pressure within the enclosed space S. Adjustment of the position of the doors 48 / 48b of the airflow distribution balancer 14# is used to adjust (desirably reduce) the load on the airflow generator motor to generate pressure, and changes in the position of the doors 48 / 48b can affect the pressure within the enclosed space S. A positive pressure is maintained within the enclosed space S by delivering sufficient fresh air F to the enclosed space S to maintain a set differential pressure within the enclosed space S.

[0135] Pressure Monitoring As an example of the operation of system 1, a detailed description is provided with particular reference to controller 11 receiving signals from one or more pressure sensors 18. Pressure sensors 18, as well as other sensors 12, are in operative communication with controller 11.

[0136] Air flow distribution balancer - First embodiment (1 motor / 1 door) In the following description of the operation of system 1, system 1 includes a first embodiment of air flow distribution balancer 14.

[0137] In the embodiment shown in the drawings, the pressure sensor 18 may be provided as at least one differential pressure sensor that senses both the air pressure in the enclosed space S inside the cabin C and the air pressure outside the enclosed space S, i.e., outside the cabin C. The pressure sensor 18 is provided in an appropriate location. For example, as shown in FIG. 3B , the pressure sensor 18 may be mounted on a wall of the shell H inside the enclosed space S. A first tube 19a extends from the pressure sensor 18 into the enclosed space S within the cabin C so that the pressure sensor 18 is exposed to the air inside the enclosed space S, thereby enabling the pressure sensor 18 to sense the air pressure inside the enclosed space S. A second tube 19b extends from the pressure sensor 18 to the outside of the enclosed space S, i.e., outside the cabin C, so that the pressure sensor 18 is exposed to the air outside the enclosed space S, i.e., outside the cabin C, thereby enabling the pressure sensor 18 to sense the air pressure outside the cabin C, i.e., outside the enclosed space S. In an alternative form (not shown), two pressure sensors may be provided. The difference between the sensed air pressure in the enclosed space S inside the cabin C and the sensed air pressure outside the enclosed space S, i.e., outside the cabin C, provides a measurement of the air differential pressure. System 1 operates to maintain the air differential pressure within a range so that a positive pressure is maintained inside the enclosed space S, i.e., so that the air pressure inside the enclosed space S within the cabin C is higher than the air pressure outside the enclosed space, i.e., outside the cabin C, by a predetermined value (i.e., a predetermined pressure value), or by an amount within a predetermined range of values ​​(i.e., a predetermined pressure range). The differential pressure value is also referred to herein as the predetermined differential pressure value and the predetermined differential pressure range.

[0138] As an example, the predetermined differential pressure value and predetermined differential pressure range may be selected from the range of 5 Pa to 300 Pa. 5 Pa is typically the minimum useful pressure differential, while 300 Pa is typically the maximum pressure differential to be used in an enclosed space with human occupants, although the system capability for pressure differentials may be up to 1,000 Pa.

[0139] The pressure sensor 18 provides an input signal related to the air differential pressure, i.e., a signal indicative of the sensed air differential pressure, to the controller 11. The controller 11 is in operative communication with the motor of the air compressor 16. Thus, the controller 11 can generate an output signal that is sent to the motor of the air compressor 16 to control the speed of the motor. Additionally, the controller 11 is in operative communication with the motor 70 of the air flow distribution balancer 14. Thus, the controller 11 can generate an output signal that is sent to the motor 70 of the air flow distribution balancer 14 to control the operation of the motor 70. The motor 70 is operated to move the door 48 to the required position.

[0140] When the controller 11 receives an input signal from the pressure sensor 18 indicating that the air differential pressure has fallen below a predetermined value (i.e., a predetermined pressure value) or has decreased by an amount within a predetermined range of values ​​(i.e., a predetermined pressure range), the controller 11 generates and sends an output signal (i) to the motor of the air compressor 16 to increase the motor's speed, and / or (ii) to the motor 70 of the air distribution balancer to move the door 48 to increase the amount or volume of fresh air that can enter the air flow distribution balancer 14. Each of these actions, i.e., (i) and (ii), increases the volume of fresh air flowing into the enclosed space S, increasing the pressure within the enclosed space S, thereby increasing the differential pressure, as described further herein.

[0141] Increasing the speed of the motor of the air compressor 16 increases the speed of the fan or impeller of the air compressor 18, thereby increasing the volume of air drawn into the air flow distribution balancer 14 via the fresh air stream F and the recirculated air stream R. The air then exits the air flow distribution balancer 14 as a single air stream A and is delivered to the enclosed space S. This increase in the volume of air in the fresh air stream F flowing into the enclosed space S increases the pressure within the enclosed space S. This increase in pressure within the enclosed space S increases the differential pressure.

[0142] Because the air in the fresh air flow F is air drawn in from outside the enclosed space S (as opposed to the recirculated air flow R which has already circulated through the system 1 and the enclosed space S), the fresh air flow F includes newly introduced air, and thus its effect is to increase the amount of fresh air flowing into the enclosed space S.

[0143] Moving the door 48 to increase the amount or volume of fresh air allowed to enter the air flow distribution balancer 14 results in the door 48 moving away from the first position toward the second position. This increases the size of the opening of the first inlet 42 and decreases the size of the opening of the second inlet 44, as previously described herein. This increases the amount of fresh air and decreases the amount of recirculated air allowed to enter the air flow distribution balancer 14. The air then exits the air flow distribution balancer 14 as a single air flow A and is delivered to the enclosed space S. This increases the amount or volume of fresh air delivered to the enclosed space S relative to the amount or volume of recirculated air R. Because more air is being introduced into the system 1 (via the increased fresh air flow F) and less recirculated air (from the enclosed space S) is allowed to enter the air flow distribution balancer 14, the pressure within the enclosed space S increases. This increased pressure within the enclosed space S increases the pressure differential.

[0144] The decision as to which motor (i.e., the motor of air compressor 16 and / or motor 70) to operate in response to an output signal from controller 11 is made by logic within controller 11. The logic of controller 11 can be programmed and updated so that the motors operate as desired in response to an output signal from controller 11. The logic within controller 11 is programmed to balance competing factors in a desired manner.

[0145] As an example, if the output signal from the controller 11 commands the motor 70 to move the door 48 but does not command the air pressurizer motor to change speed, the door 48 will be moved toward the second position. This increases the opening of the first inlet 42 (fresh air inlet), thereby increasing the amount of fresh air that can enter the chamber 52 of the air flow distribution balancer 14 and flow into the enclosed space S. This increased flow of fresh air into the enclosed space S increases the air pressure within the enclosed space S. In this manner, the pressure within the enclosed space S is increased without changing the speed of the air pressurizer 16 motor. This is desirable for maximizing the efficiency and life of the air pressurizer 16 motor. Additionally, air pressurizer motors typically emit less noise when operated at a slower speed, which is also desirable for noise reduction. However, moving door 48 to increase the size of the opening of first inlet 42 (increasing the amount or volume of fresh air flowing into enclosed space S) simultaneously reduces the size of the opening of second inlet 44 (i.e., the recirculated air inlet). Reducing the size of the opening of second inlet 44 reduces the amount or volume of recirculated air (relative to fresh air) flowing into chamber 52 and enclosed space S. Additionally, the amount or volume of recirculated air filtered by filters in system 1 (i.e., the filter in air compressor 16 and, if present, filter 31, such as a fine particle filter) is reduced. The flow of recirculated air through system 1 is desirable because it reduces the accumulation of dust particles that may enter enclosed space S through open doors, gaps, or be carried on the clothing of personnel entering the enclosed space. The accumulation of such dust particles is mitigated by the flow of recirculated air through system 1 because the recirculated air is filtered as it flows through system 1 (i.e., by a filter in air compressor 16 and, if present, a filter 31, such as a fine particle filter).Additionally, if the enclosed space S has an existing air conditioning system (e.g., in an HVAC system), maintaining a relatively high level of recirculated airflow through the system or maximizing the recirculated airflow may be beneficial to reduce air conditioner load because it reduces the proportion of fresh air, which may be hot or cold, that must be cooled or heated by the air conditioner.

[0146] An under-pressure condition is indicated when the controller 11 determines that the pressure sensor 18 senses that the air differential pressure has fallen below a predetermined value or below a predetermined range of values ​​(i.e., a steady-state condition for the pressure parameter). When the controller 11 receives a signal from the pressure sensor 18 that the air differential pressure has fallen below a predetermined value or below a predetermined range of values, the controller 11 sends a signal to the motor of the air pressurizer 16 and / or the motor 70 associated with the door 48 / 48b to adjust their operation.

[0147] In an under-pressure condition, when the controller 11 sends a signal to the motor of the air compressor 16, the signal commands the motor to increase its speed. This increases the motor's speed, which in turn increases the speed of the fan or impeller of the air compressor 16. As a result, the amount or volume of air (i.e., air flow velocity) flowing through the air distribution balancer 14 and the air compressor 16 into the enclosed space S increases. As a result, the air pressure within the enclosed space S increases (i.e., rises), thereby increasing the air differential pressure.

[0148] In an under-pressure condition, when the controller 11 sends a signal to the motor 70 associated with the door 48 / 48b, the signal commands the motor 70 to increase the size of the opening of the first inlet 42 (i.e., the fresh air inlet), thereby increasing the amount or volume of fresh air that can enter the chamber 52, flow through the air flow distribution balancer 14 and air pressurizer 16, and then into the enclosed space S. This increased flow of fresh air into the enclosed space S results in an increase in the air pressure within the enclosed space S, thereby increasing the air differential pressure.

[0149] Conversely, an overpressure condition is indicated when the controller 11 determines that the pressure sensor 18 senses that the air differential pressure has risen above a predetermined value or above a predetermined range of values ​​(i.e., a steady-state condition for the pressure parameter). When the controller 11 receives a signal from the pressure sensor 18 indicating that the air differential pressure has risen above a predetermined value or above a predetermined range of values, the controller 11 sends a signal to the motor of the air pressurizer 16 and / or the motor 70 associated with the door 48 / 48b to adjust their operation.

[0150] In an overpressure condition, when the controller 11 sends a signal to the motor of the air compressor 16, the signal commands the motor to reduce the speed of the motor of the air compressor 16. This reduces the speed of the motor, which in turn reduces the speed of the fan or impeller of the air compressor 16. As a result, the amount or volume of air (i.e., air flow velocity) flowing through the air distribution balancer 14 and the air compressor 16 into the enclosed space S decreases. As a result, the air pressure within the enclosed space S decreases (i.e., drops), thereby reducing the air differential pressure.

[0151] In an overpressure condition, when the controller 11 sends a signal to the motor 70 associated with the door 48 / 48b, the signal commands the motor 70 to reduce the size of the opening of the first inlet 42 (i.e., the fresh air inlet). As a result, the amount or volume of fresh air that can enter the chamber 52, flow through the air flow distribution balancer 14 and the air pressurizer 16, and then into the enclosed space S is reduced. This reduction in fresh air flow into the enclosed space S results in a decrease in the air pressure within the enclosed space S, thereby reducing the air differential pressure.

[0152] Thus, in response to a signal received from pressure sensor 18 indicating an overpressure or underpressure condition, controller 11 issues a signal to the motor of air pressurizer 16 and / or the motor 70 associated with door 48 / 48b to adjust (either by increasing or decreasing) the speed of the motor of air pressurizer 16 and / or move door 48 / 48b to maintain the air differential pressure at a predetermined value or within a predetermined range of values.

[0153] If the signal received by the controller 11 from the pressure sensor 18 indicates that the air differential pressure matches a predetermined value or is within a predetermined range of values, the controller 11 issues an output signal commanding the air pressurizer motor to maintain the current motor speed, i.e., the motor speed remains unchanged, and commanding the motor 70 to maintain the door 48 / 48b in its current position, i.e., the position of the door 48 / 48b remains unchanged.

[0154] In an alternative embodiment (not shown), at least two pressure sensors (not differential pressure sensors) may be provided. In this alternative embodiment in which two pressure sensors are provided, one pressure sensor senses the air pressure in the enclosed space S inside the cabin C, and a second pressure sensor senses the air pressure outside the cabin C (i.e., outside the enclosed space S). Each of these pressure sensors sends a signal to the controller 11 regarding the air pressure sensed by the respective pressure sensor, i.e., a signal indicative of the respective sensed air pressures inside the cabin C and in the enclosed space S outside the cabin C. The controller 11 receives the signals from the two pressure sensors and calculates the air differential pressure. The controller 11 then functions, and the system 1 operates, in the manner previously described herein with reference to the embodiment in which the pressure sensor 18 is a differential pressure sensor.

[0155] In an alternative embodiment (not shown), the pressure monitored is the air pressure within the confined space S. A pressure sensor is provided to sense the air pressure within the confined space S. The pressure sensor sends a signal to the controller 11 regarding the air pressure sensed by the pressure sensor, i.e., a signal indicative of the sensed air pressure inside the confined space S within the cabin C. The controller 11 receives the signal from the pressure sensor. In this embodiment, the system maintains the sensed air pressure inside the confined space S within a range such that the sensed air pressure is above a selected value to maintain a positive pressure inside the confined space S. The selected value is a value selected to be greater than the expected air pressure outside the confined space S by a desired amount. The controller 11 functions and the system of this embodiment operates in a similar manner as described above in this specification with reference to the embodiment in which the pressure sensor 18 is a differential pressure sensor. The difference is that in this embodiment, the controller 11 responds to a signal from the pressure sensor indicative of the air pressure within the confined space (rather than a signal indicative of an air differential pressure).

[0156] In most applications, it will be advantageous to use the differential pressure as a parameter for the controller 11 to control the operation of the system components, as previously described herein. The differential pressure allows a desired differential pressure to be set, and the system will operate to maintain the set differential pressure regardless of changes in air pressure outside or inside the enclosed space S.

[0157] Air Flow Distribution Balancer - Second Embodiment (Different Size Inlets) In the following description of the operation of system 1, system 1 includes a second embodiment air flow distribution balancer 14a.

[0158] When the second embodiment air flow distribution balancer 14a is used in system 1, system 1 operates in a manner substantially similar to that described hereinabove with reference to operation when the first embodiment air flow distribution balancer 14 is used. The difference is that because the cross-sectional areas of first inlet 42a and second inlet 44a are different, moving door 48 disproportionately changes the amount or volume of fresh air and recirculated air entering air flow distribution balancer 14a and entering chamber 52 of air flow distribution balancer 14a.

[0159] Air flow distribution balancer - Third embodiment (2 motors / 2 doors) In the following description of the operation of system 1, system 1 includes a third embodiment of air flow distribution balancer 14b.

[0160] When the third embodiment air flow distribution balancer 14b is used in system 1, system 1 operates in a manner substantially similar to that described above with reference to operation when the first embodiment air flow distribution balancer 14 is used. The difference is that the first inlet 42 and the second inlet 44 each have a door 48b, and because the two doors 48b are independently movable, each door 48b can be moved to adjust the size of the opening of the inlet 42 or 44 without changing the size of the opening of the other inlet 44 or 42. This provides a greater degree of control over the amount or volume of fresh air and recirculated air that can flow into chamber 52 within air flow distribution balancer 14b than is possible with an air flow distribution balancer using only a single door 48. Additionally, controller 11 is in operative communication with each motor 70 of air flow distribution balancer 14b. Thus, controller 11 can generate respective output signals that are sent to each motor 70 of air flow distribution balancer 14b to control operation of each motor 70. Motors 70 are operated to move each door 48b to the required position.

[0161] Air flow distribution balancer - fourth embodiment (combination of second and third embodiments) In the following description of the operation of system 1, system 1 includes the air flow distribution balancer of the fourth embodiment.

[0162] When the fourth embodiment air flow distribution balancer is used in system 1, system 1 operates in a manner substantially similar to that previously described herein with reference to operation when the first, second, and third embodiment air flow distribution balancers 14, 14a, 14b are used. As a result of the difference in cross-sectional area between first inlet 42 and second inlet 44, the amount or volume of fresh and recirculated air that can flow into air flow distribution balancer chamber 52 varies non-proportionally, and the two independently movable doors 48b provide a greater degree of control over the amount or volume of fresh and recirculated air that can flow into air flow distribution balancer chamber 52.

[0163] CO2 monitoring With respect to the operation of the system 1 when the controller 11 receives a signal from the CO2 sensor 22 within the system 1, the system 1 operates in a manner similar to that described hereinabove with reference to the operation of the controller 11 when it receives a signal from the pressure sensor 18 within the system 1. In that regard, increasing the fresh air flow simultaneously increases the pressure and decreases the CO2 concentration within the enclosed space S.

[0164] Each CO2 sensor 22 is in operative communication with the controller 11. Each CO2 sensor 22 provides an input signal to the controller 11 related to the CO2 level within the enclosed space S. The system 1 operates to maintain the CO2 level within the enclosed space S below a predetermined value (i.e., a predetermined CO2 value).

[0165] Monitoring other gases If the vehicle in which system 1 is installed is operating in an environment where one or more undesirable gases (e.g., H2S, SO2, and / or a refrigerant gas such as R-1234YF) may be present, filter 31 may comprise an activated carbon filter, as previously described herein. FIG. 1B illustrates system 1B including an activated carbon filter as one of filters 31. In FIG. 1B, the activated carbon filter is identified by reference numeral 31a. In FIG. 1B, activated carbon filter 31a is shown as being provided in fresh air flow F. Activated carbon filter 31a is provided upstream of first inlet 42 of air flow distribution balancer 14. Activated carbon filter 31a is provided downstream of air precleaner 32. Activated carbon filter 31a is provided upstream of air flow sensor 24, which is provided in fresh air flow F. A fine particle filter (identified by reference numeral 31b in FIG. 1B) is provided upstream of activated carbon filter 31a (i.e., activated carbon filter 31a is provided downstream of filter 31b), which is provided downstream of air precleaner 32.

[0166] When an activated carbon filter 31a is included in an embodiment of the system described herein, at least one fine particle filter is also included. When two (or more) such fine particle filters are included, at least one particulate filter is provided upstream of the activated carbon filter and at least one fine particle filter is provided downstream of the activated carbon filter 31a. This arrangement is illustrated in FIG. 1B, which shows a fine particle filter 31b provided upstream of the activated carbon filter 31a. In FIG. 1B, filter 31 is positioned between the air compressor 16 and the air outlet unit U (as in FIG. 1A) and is provided downstream of the activated carbon filter 31a.

[0167] 1B, when the controller 11 receives a signal from the gas sensor 26 in the system 1 (which monitors other undesirable gases in the confined space S), the system 1 operates in a manner similar to that described hereinabove with reference to operation when the controller 11 receives a signal from the pressure sensor 16 or the CO2 sensor 22 in the system 1. In that regard, increasing the fresh air flow simultaneously increases the pressure and decreases the concentration of other undesirable gases in the monitored confined space S.

[0168] In an alternative embodiment (not shown), an activated carbon filter 31a is provided in the single air flow A downstream of the air flow distribution balancer (instead of, or in addition to, the activated carbon filter 31a in the fresh air flow F, as shown in FIG. 1B ). However, because the activated carbon filter 31a in the single air flow A filters air from both the fresh air flow F and the recirculated air flow R, it is generally not necessary to also have an activated carbon filter 31a in the fresh air flow F. A fine particle filter 31 is provided upstream of the activated carbon filter 31a in the single air flow A. For example, in the implementation of system 1b shown in FIG. 1B , this could be the fine particle filter 31b in the fresh air flow F; however, if the fine particle filter 31b were not present in the fresh air flow F, the fine particle filter 31 in the single air flow A would be located upstream of the activated carbon filter 31a located in the single air flow A. Thus, the activated carbon filter 31a would be located in the single air flow A so as to be located between the fine particle filter 31 and the enclosed space S (particularly the outlet unit U). As described herein above, the activated carbon filter 31 a in the single air flow A filters air from both the fresh air flow F and the recirculated air flow R. Thus, if undesirable gases are present in the recirculated air flow R (which may occur, for example, when an operator opens the door to the cabin C and undesirable gases enter the enclosed space S from outside the enclosed space S), the activated carbon filter 31 a in the single air flow A filters the undesirable gases after they flow through the air flow distribution balancer into the recirculated air flow R and become part of the single air flow A. On the other hand, if the activated carbon filter 31 a were located in the fresh air flow F (as shown in FIG. 1B ), the undesirable gases in the enclosed space S could also be reduced by simply diluting the level of undesirable gases in the enclosed space S by increasing the filtered fresh air flow F.

[0169] In a further alternative embodiment (not shown), an activated carbon filter 31a is provided in the recirculated air stream R (in addition to the activated carbon filter 31a in the fresh air stream F, as shown in FIG. 1B). When an activated carbon filter 31a is provided in the recirculated air stream R, increasing the recirculated air stream R reduces the level of undesirable gases in the enclosed space S because the increased recirculated air stream R causes more air to flow into the recirculated air stream R and thus through the activated carbon filter 31a. The air volume of the recirculated air stream R can be increased by moving the door 48 of the air flow distribution balancer 14 to increase the size of the opening of the second inlet 44 (recirculated air stream R).

[0170] If only one fine particle filter 31 is provided in a system having an activated carbon filter 31a, it is advantageous to provide the fine particle filter 31 upstream of the activated carbon filter 31. This is because the fine particle filter 31 removes fine particles from the air, whereas the activated carbon filter 31a removes undesirable gases from the air but is ineffective at removing most fine particles from the air. Therefore, locating the fine particle filter 31 upstream of the activated carbon filter 31a means that the air passing through the activated carbon filter 31a (after passing through the fine particle filter 31) is relatively free of debris that could otherwise damage or reduce the efficiency of the carbon bed in the activated carbon filter 31a. If two fine particle filters 31 are provided in a system having an activated carbon filter 31a, locating one of these two fine particle filters 31 downstream of the activated carbon filter 31a captures pulverized carbon particles within the activated carbon filter 31a. The fine particle filter 31 downstream of the activated carbon filter 31a experiences significantly less clogging than the fine particle filter 31 upstream of the activated carbon filter 31a. Thus, the fine particle filter 31 downstream of the activated carbon filter 31a may be a lower grade filter than the fine particle filter 31 upstream of the activated carbon filter 31a, provided that the upstream fine particle filter 31 is an appropriately higher grade filter, e.g., a HEPA or similar grade filter.

[0171] Each gas sensor 26 is in operative communication with the controller 11. Each gas sensor 26 provides an input signal to the controller 11 regarding the level of an undesirable gas within the enclosed space S. The system 1 operates to maintain the level of such undesirable gas within the enclosed space S below a predetermined value (i.e., a predetermined undesirable gas value).

[0172] Dust Monitoring Each dust sensor 20 is in operative communication with the controller 11. Each dust sensor 20 provides an input signal to the controller 11 regarding the dust level within the enclosed space S. The system 1 may operate to maintain the dust level within the enclosed space S below a predetermined value (i.e., a predetermined dust value).

[0173] When the controller 11 receives a signal from the dust sensor 20 indicating that the dust level within the enclosed space S has risen above a predetermined value, the system 1 operates to reduce the sensed dust level below the predetermined value. This is done by increasing the filtration of the air within the enclosed space S to increase the removal of dust from the air within the enclosed space S. Filtration of the air within the enclosed space S is increased by drawing more air from the enclosed space S via the third duct 33c, which then flows in the recirculated airflow R and through the filters in the air flow distribution balancer 14 and air pressurizer 16 and, if present, the additional filter 31. This is accomplished by the controller 11 generating and sending an output signal to the motor 70 associated with the door 48 / 48b to increase the size of the opening of the second inlet 44 / 44a of the air flow distribution balancer. In addition, the speed of the motor of the air pressurizer 16 is increased, thereby increasing the recirculated airflow R. As the recirculated air flow R enters the air flow distribution balancer 14 via the second inlet 44 / 44a, an increased amount or volume of recirculated air flows through the air flow distribution balancer 14 and through the filter in the air compressor 16 and the additional filter 31, if present. As a result, the amount or volume of filtered recirculated air (from the enclosed space S) increases. That is, the filtration rate of the air (from the enclosed space S) by the filters in the system 1 increases. By increasing the filtration rate, more dust particles are removed from the air in the enclosed space S.

[0174] When the controller 11 receives a signal from the dust sensor 20 that the dust level has dropped below a predetermined value (i.e., the steady state condition of the dust parameter), the controller 11 sends a signal to the motor 70 associated with the door 48 / 48b to reduce the size of the opening of the second inlet 44 / 44a of the air flow distribution balancer 14. The door 48 / 48b then returns to its previous position, and the amount or volume of recirculated air flowing through the air flow distribution balancer 14 and through the filter in the air compressor 16 and, if present, the additional filter 31, returns to its previous level.

[0175] If the signal received by the controller 11 from the dust sensor 20 indicates that the dust level matches or is within a predetermined range of values, the controller 11 issues an output signal instructing the motor 70 to maintain the door 48 / 48b in its current position.

[0176] Thus, the system 1 increases the amount or volume of recirculated air flow R into the enclosed space S to control dust levels, while the system increases the amount or volume of fresh air flow F into the enclosed space S if the pressure is to be maintained or CO2 and undesirable gases are to be maintained at a predetermined value.

[0177] Airflow Monitoring Regarding the operation of the system 1 when the controller 11 receives a signal from the air flow sensor 24 in the system 1, the controller may issue an output signal to the air pressurizer motor and / or the motor 70 of the door 48 / 48b.

[0178] Each airflow sensor 24 is in operative communication with the controller 11. Each airflow sensor 24 provides an input signal to the controller 11 related to the airflow at the location of the airflow sensor 24. The system 1 operates to maintain the airflow within the system 1 above a respective predetermined value (i.e., a predetermined airflow value). This ensures that desired levels of fresh filtered air and recirculated filtered air from the air pressurizer 16 are delivered to the enclosed space S. As previously described herein, by providing respective airflow sensors 24 for the fresh air stream F, the recirculated air stream R, and the single air stream A, input signals from the locations of each of these air streams are provided to the controller 11.

[0179] The signal provided by the airflow sensor 24 to the controller 11 also serves to verify that the arrangement of the airflow distribution balancer doors 48 / 48b is proportionally distributing the correct ratio of fresh air to recirculated air.

[0180] The controller 11 responds to the signals received from the airflow sensor 24 by generating and sending output signals to the motor of the air compressor 16 (to increase or decrease the motor's speed) and / or the motor 70 of the door 48 / 48b (to move the door 48 / 48b) in the manner previously described herein, mutatis mutandis, to maintain the airflow at each predetermined airflow value and / or ensure that the proper ratio of fresh air to recirculated air to the airflow distribution balancer is maintained.

[0181] System - Second Embodiment FIG. 4 is a schematic diagram illustrating a second embodiment of a system 2 for monitoring and controlling air quality in an enclosed space S, installed in a vehicle having a cabin C.

[0182] The components and features of System 2 of the second embodiment are similar to those of System 1 of the first embodiment, except that System 1 uses a filterless air pressurizer 16 and a separate filter 31 in the single air flow A between the air pressurizer 16 and the air outlet unit U, whereas System 2 has a filter in its air pressurizer 16a. The filter in the air pressurizer 16a is typically a relatively high-grade filter, providing the filtering capability of the filter 31 in System 1 of the first embodiment for filtering dust particles. Thus, the filter in the air pressurizer 16a may comprise, for example, a HEPA filter, a ULPA filter, an EPA filter, or other filter capable of filtering fine particles. However, if the filter in the air pressurizer 16a does not provide the level of filtration required for a particular environment, one or more separate filters 31 can be provided in System 2 (as described previously in this specification with reference to System 1 of the first embodiment).

[0183] In other respects, the system 2 of the second embodiment and its use and operation are similar to the system 1 of the first embodiment described hereinabove. System - Third to Seventh Embodiments 5 to 9 are schematic diagrams showing third to seventh embodiments of systems 3, 4, 5, 6, and 7, respectively, for monitoring and controlling air quality in an enclosed space S, installed in a vehicle having a cabin C. Each of systems 3, 4, 5, 6, and 7 can provide an increased recirculated airflow R as needed, compared to system 1 of the first embodiment or system 2 of the second embodiment.

[0184] System - Third embodiment The components and features of the third embodiment of system 3, shown schematically in Figure 5, are similar to those of the first embodiment of system 1, except that system 3 includes a blower B and a bypass valve 79 (also referred to herein as the "first bypass valve") for the recirculated air flow R. Specifically, return air unit N includes blower B and bypass valve 79, as best shown in Figures 10 and 11. Blower B includes a motor and a fan or impeller. The motor drives the fan or impeller of blower B. Bypass valve 79 can be opened or closed to allow or prevent airflow therethrough.

[0185] Blower B and controller 11 are in operative communication such that controller 11 can generate and send output signals to blower B to regulate and control the operation of blower B, i.e., the speed of the fan or impeller of blower B. Blower B is provided inside return air unit N, adjacent to an air inlet I of return air unit N. Blower B operates to draw air from enclosed space S into return air unit N.

[0186] The bypass valve 79 and the controller 11 are in operative communication such that the controller 11 can generate and send output signals to the bypass valve 79 to open or close the bypass valve 79. The bypass valve 79 is provided in a wall W of the return air unit N. The bypass valve 79 operates to return air from the return air unit N to the enclosed space S when the bypass valve 79 is open. The bypass valve 79 allows a portion of the air from the enclosed space S (en route to enter the recirculated airflow R) to (instead of) return to the enclosed space S (through the return air unit N). In other words, a portion of the air is returned to the enclosed space S via the bypass valve 79 instead of entering the recirculated airflow R. The filter T filters the air before it enters the return air unit N through the blower B. As a result, the air entering the enclosed space S through the bypass valve 79 (when open) is filtered air. The filter T is provided at the inlet I of the return air N. The bypass valve 79 can be placed in a closed position (no air can flow through the bypass valve 79), an open position (the bypass valve 79 is fully open, allowing maximum airflow through the bypass valve 79), or an intermediate position where the bypass valve 79 is partially open (allowing less than maximum airflow through the bypass valve 79).

[0187] In addition to the blower B and the bypass valve 79, the system 3 further includes a pressure sensor 18a. The pressure sensor 18a is disposed downstream of the blower B. The pressure sensor 18a is disposed inside the return air unit N.

[0188] The system 3 of the third embodiment is also suitable for use to address several ISO standards. For example, the standard ISO 23875 for confined spaces requires a decay time of 120 seconds. The decay time is determined by this standard when the cabin particulate concentration is between 2000 and 5000 μg / m 3 to 25 μg / m 3, defined as the time it takes for the recirculated airflow R to decrease as follows: Many systems, including the first embodiment system 1 and the second embodiment system 2 described above, may have difficulty providing sufficient recirculated airflow to meet the standard, particularly in enclosed spaces with relatively large volumes and existing air conditioning systems. This is because the air compressor and blower may not be able to overcome the limitations of the existing air conditioning ductwork and particulate filters required by the standard. In contrast, the third embodiment system 3, which can provide increased recirculated airflow R as needed, can function in a manner that meets the ISO standard.

[0189] Use and Operation: System - Third Embodiment The following description of the use and operation of system 3 is limited to the use and operation resulting from the inclusion of blower B, bypass valve 79, and pressure sensor 18a within system 3. However, it should be understood that the use and operation of system 1 of the first embodiment as described herein above also applies to system 3 of the third embodiment.

[0190] In standard operation, the fan or impeller speed of blower B matches the demands of air compressor 16 to provide enough air for recirculating airflow R. This maintains the pressure inside the compartment housing blower B (in return air unit N) at the same pressure as the pressure in enclosed space S. In that regard, the pressure in enclosed space S serves as the reference pressure for pressure sensor 18a, which can be expected to detect the ambient pressure level within blower B. Under standard or normal operating conditions, blower B provides enough air to air compressor 16. Under standard or normal operating conditions, bypass valve 79 is in a closed position. The closed position of bypass valve 79 is shown in FIG. 10.

[0191] If pressure sensor 18a senses a negative pressure reading (indicating a negative pressure in third duct 33c), this indicates that air pressurizer 16 is drawing in more air than blower B is supplying. When controller 11 receives an input signal from pressure sensor 18a indicating a negative pressure reading, an output signal generated by controller 11 and sent to blower B commands blower B to increase the fan or impeller speed until the pressure sensed by pressure sensor 18a is equal to or greater than ambient pressure. Bypass valve 79 remains in a closed position (as shown in FIG. 10).

[0192] In contrast, if pressure sensor 18a senses a positive pressure reading (indicating positive pressure in third duct 33c), this suggests that ductwork and / or filters in system 3 are restricting the amount or volume of air that can flow in recirculated airflow R. When controller 11 receives an input signal from pressure sensor 18a indicating a positive pressure reading, controller 11 generates and sends an output signal to blower B to reduce the fan or impeller speed until the pressure sensed by pressure sensor 18a is within a predetermined range of ambient pressure or until the blower B motor reaches a minimum predetermined speed. The minimum predetermined speed may correspond to the motor's stall speed. In this normal operation, bypass valve 79 is opened only when the blower B motor reaches minimum speed and positive pressure is still sensed by pressure sensor 18a. When the bypass valve 79 is open, some air is allowed to bypass the third duct 33c and instead flow from inside the return air unit N back to the enclosed space S. This provides sufficient recirculated air to the enclosed space S. The open position of the bypass valve 79 is shown in Figure 11. Figure 11 shows that some air enters the third duct 33c from inside the return air unit N through the opening 35b (i.e., recirculated air flow R), and some air bypasses the third duct 33c and returns to the enclosed space (as shown by arrow P) through the open bypass valve 79. In contrast to this, in Figure 10, the bypass valve 79 is closed, so that air from the return air unit N can only flow into the duct 33c.

[0193] System 3 also provides a high-speed scrubbing or cleaning function (also referred to herein as scrub mode). In that regard, controller 11 can generate and send an output signal to bypass valve 79 and blower B to fully open the bypass valve 79 and maximize the fan or impeller speed of blower B. This rapidly increases airflow through enclosed space S, scrubbing or cleaning the air within enclosed space S. Other embodiments of Systems 1, 2, and 4-10 described herein also provide a scrub mode. In scrub mode, recirculated airflow R is maximized. This can be achieved by adjusting the doors 48 / 48b of the airflow distribution balancer to allow maximum recirculated airflow R (and minimum fresh airflow F). However, system embodiments with blower B and bypass valve 79 can achieve a greater recirculated airflow R than embodiments without blower B and bypass valve 79. Scrub mode is further described herein with reference to FIGS. 25C and 25D.

[0194] The input signal received by controller 11 from pressure sensor 18a (indicative of the pressure within return air unit N) may be used to detect blockages in recirculated air flow R, such as blockages caused by an obstruction before (i.e., upstream of) filter T. By way of example, if pressure sensor 18a senses a negative pressure reading and the sensed pressure does not change (i.e., increase) significantly (e.g., by a predetermined amount) with an increase in the speed of the fan or impeller of blower B, logic within controller 11 may conclude that filter T is blocked. Controller 11 may then issue an alarm. The alarm may indicate to an operator that maintenance is required and that appropriate corrective action may be taken.

[0195] System - Fourth embodiment The components and features of the fourth embodiment system 4, shown schematically in Figure 6, are similar to those of the third embodiment system 3, except that in system 4, an air compressor 16 and a filter 31 are provided in the fresh air flow F flowing to the fresh air inlet 42. Thus, the air compressor 16 and the filter 31 are provided upstream of the air flow distribution balancer 14. As can be seen in Figure 5, the air compressor 16 and the filter 31 are provided between the precleaner 32 and the air flow sensor 24.

[0196] In contrast, in the third embodiment system 3, the air pressurizer 16 and filter 31 are provided downstream of the air flow distribution balancer 14 within the single air flow A exiting the air flow distribution balancer 14.

[0197] In other respects, the system 4 of the fourth embodiment and its use and operation are similar to the system 3 of the third embodiment described hereinabove. System - Fifth embodiment The components and features of the fifth embodiment of system 5, shown schematically in Figure 7, are similar to those of the fourth embodiment of system 4, except that in system 5, the order of the air compressor 16 and the filter 31 is reversed. That is, in system 5, fresh air flows from the precleaner 32, through the filter 31, and then through the air compressor 16. In contrast, in the fourth embodiment of system 4, fresh air flows from the precleaner 32, through the air compressor 16, and then through the filter 31.

[0198] In other respects, the system 5 of the fifth embodiment and its use and operation are similar to the system 4 of the fourth embodiment described hereinabove. System - Sixth Embodiment The components and features of system 6 of the sixth embodiment, shown schematically in Figure 8, are similar to the components and features of system 3 of the third embodiment (shown in Figure 5), except that system 3 uses an air pressurizer 16 (without a filter) and a separate filter 31 in the single air flow A between the air pressurizer 16 and the air outlet unit U, whereas system 6 uses a filter in air pressurizer 16a of system 6. The filter in air pressurizer 16a of system 6 is similar to the filter in air pressurizer 16a of system 2 of the second embodiment described above.

[0199] In other respects, the system 6 of the sixth embodiment and its use and operation are similar to the system 3 of the third embodiment described hereinabove. System - Seventh embodiment The components and features of the seventh embodiment of system 7, shown schematically in Figure 9, are similar to those of the sixth embodiment of system 6, except that in system 7, an air pressurizer 16a is provided in the fresh air flow F flowing to the fresh air inlet 42. To this end, the air pressurizer 16a is provided upstream of the air flow distribution balancer 14. As can be seen in Figure 9, the air pressurizer 16a is provided between the precleaner 32 and the air flow sensor 24.

[0200] In contrast, in the sixth embodiment of the system 6, the air pressurizer 16a is provided downstream of the air flow distribution balancer 14 within the single air flow A exiting the air flow distribution balancer 14.

[0201] In other respects, the system 7 of the seventh embodiment and its use and operation are similar to the system 6 of the sixth embodiment described hereinabove. System - Eighth embodiment FIG. 27 is a schematic diagram illustrating an eighth embodiment of a system 8 for monitoring and controlling air quality in an enclosed space S, installed in a vehicle having a cabin C.

[0202] While the system embodiments previously described herein include a single airflow distribution balancer, the eighth embodiment of system 8 includes two airflow distribution balancers: one airflow distribution balancer is used to control the fresh airflow F, and the second airflow balancer is used to control the recirculated airflow R.

[0203] The components and features of system 8 of the eighth embodiment are similar to those of system 3 of the third embodiment, except that system 3 has a single airflow distribution balancer 14, whereas system 8 has two airflow distribution balancers, identified by reference numeral 14d. Airflow distribution balancer 14d may be any one of the airflow distribution balancers 14# of the first, second, third, and fourth embodiments described hereinabove, except that one of the inlets (i.e., either first inlet 42 / 42a or second inlet 44 / 44a) is permanently closed or blocked. In the case of airflow distribution balancer 14b of the third embodiment, one of doors 48b is permanently closed to prevent airflow through the corresponding inlet, regardless of whether it is inlet 42 or inlet 44. When one of the other embodiments of the airflow distribution balancer is used as the airflow distribution balancer 14d, one of the inlets of the airflow distribution balancer 14d is blocked so that only one of the inlets receives an airflow. Thus, movement of the door 48 acts to open or close only one of the inlets, i.e., the inlet that can receive one airflow. One airflow distribution balancer 14d receives the fresh airflow F, and the other airflow distribution balancer 14d receives the recirculated airflow R.

[0204] Referring specifically to Figure 27, a first air flow distribution balancer 14d is disposed within the fresh air flow F. This first air flow distribution balancer 14d is provided in a location similar to the location of the air flow distribution balancer 14 in system 3. This first air flow distribution balancer 14d receives only fresh air F. Figure 28 shows the first air flow distribution balancer 14d with a fresh air inlet 42 connected to the outlet of the air precleaner 32. This allows the first air flow distribution balancer 14d to receive the fresh air flow F. The outlet 46 of the first air flow distribution balancer 14d is connected to the inlet 29 of the air compressor 16.

[0205] A second airflow distribution balancer 14d is disposed in the recirculated airflow R. This second airflow distribution balancer 14d is located in the recirculated airflow R between the return air unit N and the outlet unit U. This second airflow distribution balancer 14d receives only the recirculated airflow R. Figures 29, 30, and 31 show the second airflow distribution balancer 14d connected to the return air unit N and the outlet unit U. A duct 33d extends from an opening 35c formed in the casing of the return air unit N to a second inlet 44 of the second airflow distribution balancer 14d. The second airflow distribution balancer 14d receives the recirculated airflow from the return air unit N via the second inlet 44. A duct 33e extends from an outlet 46 of the second airflow distribution balancer 14d to an opening formed in the casing of the outlet unit U. The recirculated airflow R flows from the second airflow balancer 14d to the outlet unit U via a duct 33e.

[0206] Two separate airflow distribution balancers 14d, one controlling the fresh air flow F and the other controlling the recirculated air flow R, allow the fresh air flow F and the recirculated air flow R to be controlled independently. This independent control of the fresh air flow F and the recirculated air flow R is also achieved in embodiments of the system that use the third embodiment air flow distribution balancer 14b with a separate door 48b for each inlet 42 / 44. However, in system 8, control of the fresh air flow F and the recirculated air flow R occurs in two separate locations: the first and second air flow distribution balancers 14d.

[0207] In system 8, both the fresh air flow F and the recirculated air flow R flow through respective first and second air flow distribution balancers 14d. The fresh air flow F and the recirculated air flow R enter the air outlet unit separately via respective ducts 33b (fresh air flow F) and 33e (recirculated air flow R). The fresh air and the recirculated air (fresh air flow F and recirculated air flow R) are mixed within the air outlet unit U to form a single air flow that is discharged from the air outlet unit U as shown by reference numeral 36a in FIG.

[0208] In situations where it is not possible to duct the fresh air flow F and the recirculated air flow R to the same air flow distribution balancer, it may be desirable to use two separate air flow distribution balancers 14d as used in system 8.

[0209] While the above-described embodiments of Systems 1 to 7 include a duct 33c extending from the return air unit N to the air flow distribution balancer 14, in System 8, such a duct 33c is not required because the recirculated air is not conveyed to the first air flow distribution balancer 14d located at the rear of the cabin C.

[0210] In other respects, the system 8 of the eighth embodiment and its use and operation are similar to the system 3 of the third embodiment described hereinabove. Air Flow Distribution Balancer - Fifth Embodiment (Single Inlet) 32 shows a fifth embodiment of an airflow distribution balancer 14e, which may be used as the airflow distribution balancer in the eighth embodiment of the system 8 shown in FIGS.

[0211] The airflow distribution balancer 14e has only a single inlet, which receives either the fresh air flow F or the recirculated air flow R. Airflow distribution balancer 14e is similar to airflow distribution balancer 14 of the first embodiment, except that airflow distribution balancer 14e has only one inlet, whereas airflow distribution balancer 14 has two inlets 42 and 44. In airflow distribution balancer 14e, instead of a second inlet, casing 40 is formed continuously without an inlet.

[0212] 12 and 32, it can be seen that in air flow distribution balancer 14e, first inlet 42 has been omitted and air flow distribution balancer 14e only has second inlet 44. In an alternative embodiment (not shown), air flow distribution balancer 14e may omit second inlet 44 and only have first inlet 42 as a single inlet.

[0213] Air flow distribution balancer 14e may be used and function in the same manner as air flow distribution balancer 14d previously described. Alternative return air unit Figures 33 and 34 show a cross-sectional view and an exploded view, respectively, of an alternative embodiment of a return air unit NR for the third to eighth embodiments of the system variously shown in Figures 5 to 32. The return air unit NR is similar to the return air unit N described hereinabove with reference to the other embodiments of the system, except that the return air unit NR has a radial filter TR. In contrast, the filter T described hereinabove with reference to the other embodiments of the system is a panel filter. The filter TR is located around the fan or impeller of the blower B. The return air unit NR may be provided with two inlets I for drawing in air, as indicated by reference numeral 36b. Air drawn into the return air unit NR through the inlets passes through the filter TR and then through the blower.

[0214] In other respects, the return air unit NR and its use and operation are similar to the return air unit N described previously herein. System - 9th embodiment (Modified HVAC system - 1 filter) FIG. 35 is a schematic diagram illustrating a ninth embodiment of a system 9 for monitoring and controlling air quality in an enclosed space S, installed in a vehicle having a cabin C.

[0215] As an alternative to the system embodiments previously described herein, system 9 includes modifications to an existing (or intended conventional) HVAC system for enclosed space S. Specifically, air outlet unit UM, shown in Figures 36 and 37, is modified to include high-capacity blower 16b. The outlet unit UM may include a bypass valve 79a (also referred to herein as a "second bypass valve") that can be opened or closed to allow or prevent airflow therethrough.

[0216] In a conventional HVAC system, fresh and recirculated air is drawn into a compartment that contains an evaporator and heater for air conditioning and a blower for moving the air. The air pushed by the blower is then directed into the ductwork of the HVAC system for distribution within the cabin or other enclosed space. In the configuration of system 9, the incoming fresh air flow F and recirculated air flow R are combined (i.e., mixed) and controlled by airflow distribution balancer 14, similar to other system embodiments previously described herein. However, system 9 includes a high-capacity blower 16b (instead of a conventional blower present in a conventional HVAC system) to provide the function of an airflow generator.

[0217] Air Flow Generator - Second Embodiment In the system embodiments described hereinabove (i.e., the embodiments of Systems 1-8), an airflow generator is provided in the form of air compressor 16. However, in System 9, the airflow generator is provided in the form of blower 16b. Blower 16b includes a motor and a fan or impeller. The motor drives the fan or impeller of blower 16b. Blower 16b is provided as a high-capacity blower. An existing (or intended conventional) HVAC system for enclosed space S is modified to replace the conventional blower (within the HVAC system) with high-capacity blower 16b. With respect to blower capacity, for example, a conventional blower may have a capacity in the range of approximately 150-250 CMH (cubic meters per hour), while high-capacity blower 16b typically has a capacity in the range of 200-700 CMH.

[0218] In system 9, high-capacity blower 16b generates fresh air flow F and recirculated air flow R. Therefore, air compressor 16 / 16a used in other system embodiments described hereinabove is not required in system 9. Because system 9 does not include air compressor 16 / 16a, the filter in air compressor 16a (if present) is also not included in system 9. However, system 9 does include one or more filters 31, as described hereinabove with reference to other embodiments. At least one of these filters 31 is a fine particle filter. Filter 31 is provided upstream of enclosed space S. As shown in FIG. 35, filter 31 may be provided downstream of air flow distribution balancer 14. Filter 31 is provided in ductwork from air flow distribution balancer 14 to cabin C. This ductwork is identified as ducts 33a and 33b in FIGS. 36 and 37. The location of filter 31 can be seen in FIGS. 35, 36, and 37. Filter 31 may be a radial filter. Since the system 9 does not include an air pressurizer 16 / 16a, the first duct 33a extends from the outlet 46 of the air flow distribution balancer 14 to the filter 31. The second duct 33b extends from the filter 31 to the outlet unit UM.

[0219] Use and Operation The high-capacity blower 16b is in operative communication with the controller 11 such that the controller 11 can generate and send output signals to the high-capacity blower 16b to regulate and control its operation. The bypass valve 79a is in operative communication with the controller 11 such that the controller 11 can generate and send output signals to the bypass valve 79a to open or close the bypass valve 79a. The bypass valve 79a is provided within the wall WM of the air outlet unit UM. The bypass valve 79a can be positioned in a closed position (air cannot flow through the bypass valve 79a), an open position (the bypass valve 79a is fully open, allowing maximum airflow through the bypass valve 79a), or an intermediate position (the bypass valve 79a is partially open, allowing less than maximum airflow through the bypass valve 79a). The closed position of the bypass valve 79a is shown in FIG. 36. The fully open position of the bypass valve 79a is shown in FIG. 37. The bypass valve 79a operates to allow air to flow from the air outlet unit UM into the enclosed space S when the bypass valve 79a is open (i.e., fully open or partially open). The bypass valve 79a causes a portion of the air in the outlet airflow A (in the air outlet unit UM) to be directed (on its way into the enclosed space S) through the bypass valve 79a (instead of through the air outlet unit UM).

[0220] A bypass valve 79a may be included to maximize filtration of the recirculated air and achieve the required decay time (as previously described herein). Similar to the bypass valve 79 in the third embodiment of System 3, the position of the bypass valve 79a in System 9 is controlled by the pressure inside the HVAC system. System 9 is equipped with a pressure sensor 18b. The pressure sensor 18b is located downstream of the high-capacity blower 16b. The pressure sensor 18b is located in the air outlet unit UM. The pressure sensor 18b may be a differential pressure sensor.

[0221] If the pressure sensor 18b senses a significant buildup of air pressure (e.g., a predetermined increase in configurable air pressure) within the system (i.e., inside the air outlet unit UM), the controller 11 generates and sends an output signal to the blower 16b to reduce the fan or impeller speed until the pressure sensed by the pressure sensor 18b is within a predetermined range of the ambient pressure or until the motor of the blower 16b reaches a minimum predetermined speed. The minimum predetermined speed may correspond to the stall speed of the motor. In this normal operation, the bypass valve 79a is opened only when the motor of the blower 16b reaches its minimum speed and a positive pressure is still sensed by the pressure sensor 18b. When the bypass valve 79a is open, some air, i.e., air flow Q (as shown in FIG. 37), can flow therethrough into the enclosed space S. As a result of the air flow Q, the pressure sensed by the pressure sensor 18b within the air outlet unit UM decreases, and the sensed air pressure within the enclosed space S correspondingly increases. The air flow Q bypasses the downstream evaporator, heater, and ductwork. The evaporator and heater in the air outlet unit UM are designated by the reference letter EH. The bypass valve 79a is located upstream of the evaporator / heater EH. By locating the bypass valve 79a upstream of the evaporator / heater EH, the air flow Q through the bypass valve 79a is prevented from being restricted by the evaporator / heater EH. Conversely, if the pressure sensor 18b senses a drop in air pressure in the air outlet unit UM (e.g., a predetermined drop in the configurable air pressure), the controller 11 sends a signal to the bypass valve 79a to close (if open) the bypass valve 79a to prevent the air flow Q from passing through. Additionally or alternatively, the controller 11 sends a signal to the motor of the blower 16b to increase the motor's speed. This increases the rotational speed of the motor's fan or impeller. Increasing the rotational speed of the fan or impeller increases the amount or volume of air drawn by the blower 16b through the air outlet unit UM, resulting in an increase in air pressure within the air outlet unit UM.

[0222] System - Tenth Embodiment (Modified HVAC System - Two Filters) FIG. 38 is a schematic diagram illustrating a tenth embodiment of a system 10 for monitoring and controlling air quality in an enclosed space S, installed in a vehicle having a cabin C.

[0223] The components and features of the system 10 of the tenth embodiment, shown schematically in FIG. 38, are similar to the components and features of the system 9 of the ninth embodiment, except that the system 10 has two filters 31.

[0224] A first filter 31 is provided upstream of the air flow distribution balancer 14. The first filter 31 is provided upstream of the first inlet 42 (fresh air flow F) of the air flow distribution balancer 14. Therefore, the first filter 31 filters only the air in the fresh intake air flow F. The first filter 31 is provided upstream of the enclosed space S. The location of the first filter 31 can be seen in Figures 38, 39, and 40. The first filter 31 may be a radial filter. A first duct 33a extends from the air outlet 46 of the air flow distribution balancer 14 to the air outlet unit UM.

[0225] A second filter 31 is provided upstream of the air flow distribution balancer 14. The second filter 31 is provided upstream of the second inlet 44 (return air flow R) of the air flow distribution balancer 14. Therefore, the second filter 31 filters only the air in the recirculated air flow R. The second filter 31 is provided downstream of the enclosed space S. The location of the second filter 31 can be seen in Figures 38, 39, and 40. The second filter 31 may be a panel filter. The second filter 31 may be disposed in the opening 35b on the shell H of the cabin C.

[0226] In other respects, the system 10 of the tenth embodiment and its use and operation are similar to the system 9 of the ninth embodiment described hereinabove. Use and Operation - Supplement As discussed above in the previous sections on the use and operation of systems 1-10 and the monitoring of various environmental parameters, controller 11 generates and transmits output signals to the motors of air compressor 16 / 16a or blower 16b and / or motor 70 of air flow distribution balancer door 48 / 48b in response to input signals received by controller 11 from sensors 12. The output signals generated and transmitted by controller 11 control the operation of the motors to adjust the speed of the fan or impeller of air compressor 16 / 16a or blower 16b and / or the position of door 48 / 48b. Changing the position of air flow distribution balancer door 48 / 48b is accomplished by adjusting the speed of air compressor 16 / 16a or blower 16b after a setpoint pressure is reached. Additionally, as discussed above in the previous sections regarding the use and operation of Systems 3-8 and the monitoring of various environmental parameters, for Systems 3-8, controller 11 also generates and transmits output signals to blower B and bypass valve 79 in response to input signals received by controller 11 from sensor 12. The output signals generated and transmitted by controller 11 control the operation of blower B and bypass valve 79. Similarly, for Systems 9 and 10, controller 11 also generates and transmits output signals to blower 16b and bypass valve 79a in response to input signals received by controller 11 from sensor 12. The output signals generated and transmitted by controller 11 control the operation of blower 16b and bypass valve 79a.

[0227] Logic within the controller 11 determines whether to adjust the speed of the motors of the air compressors 16 / 16a or blowers 16b or move the doors 48 / 48b to a different position. For example, the controller 11 can use a cost function to make this decision.

[0228] By way of example, in most environments in which systems 1-10 are used, the primary sensor is a pressure sensor 18. Thus, if only one type of sensor 12 is used, it is typically one or more pressure sensors 18. However, one or more CO2 sensors 22 may be included in a typical implementation. In such implementations, maintaining pressure levels at a predetermined value or within a predetermined range of values ​​and maintaining CO2 levels below a predetermined value are priorities for systems 1-10. As described elsewhere herein, other system implementations may further include one or more particulate (or dust) sensors and / or gas sensors. Particulate and gas levels are also controlled to maintain them below predetermined values.

[0229] Flow diagram By way of example, Figures 25A, 25B, 25C, 25D, and 26 illustrate flow diagrams of control system operating processes that may be used to implement the above-described Systems 1-10. For ease of explanation and understanding, the main operating processes after system startup are divided into three separate flow diagrams identified herein as "Normal System Operation" (Figure 25A), "Calibration Function Operation" (Figure 25B), and "Air Quality Check Operation" (Figure 25C); in addition, operating processes for "Scrub Mode Operation" and "Cost Function Operation" are shown separately in Figures 25D and 26, respectively.

[0230] FIG. 25A (“Normal System Operation”) shows an exemplary embodiment of a control process the system follows upon power-up. FIG. 25B (“Calibration Function Operation”) shows an exemplary embodiment of a control process for optimizing the motor speed of pressurizer 16 / 16a and / or blower B / 16b and the position of the door (48 / 48b) of airflow distribution balancer 14#. The calibration function is executed upon initial startup or when triggered by the user. FIG. 25C (“Air Quality Check Operation”) shows an exemplary embodiment of a control process for responding to an internal particulate exceedance, internal CO2 exceedance, internal gas exceedance, or external gas exceedance using air quality sensor 12. The air quality check ends when the sensed values ​​are all within set thresholds (i.e., predetermined values ​​or ranges of values). FIG. 25D (“Scrub Mode Operation”) shows an exemplary embodiment of a control process for filtering air within enclosed space S. The scrub mode is activated when a high particulate concentration is sensed within enclosed space S and there is no internal CO2 exceedance or internal gas exceedance. FIG. 26 (“Cost Function Calculation”) shows an exemplary embodiment of a control process for adjusting the doors 48 / 48b of the airflow distribution balancer 14# if, during calibration, the motor speed of the pressurizer 16 / 16a and / or blower B / 16b drifts from its optimized value; the cost function is triggered if the motor speed (Speed_F) of the pressurizer 16 / 16a and / or blower B / 16b at the setpoint pressure drifts above the calibrated value by a predetermined amount; a similar function may be used if Speed_F drifts below the calibrated value by a predetermined amount.

[0231] 25A, at start-up or power-on (1001), the sensors 12 are initialized (1002), and then a system process checks (1003) the calibration of the motor speeds of the pressurizers 16 / 16a and blowers B / 16b and the door (48 / 48b) position of the airflow distribution balancer 14#, which optimizes the motor speeds and door positions. If calibration is required, the system process moves to a calibration function (1004).

[0232] Calibration Function The calibration function (1004) is shown separately in FIG. 25B. When the calibration function (1004) begins (1005), an output signal from the controller 11 in the system 1-10 commands the motor 70 to move the door 48 / 48b to fully open the fresh air inlet 42 / 42a (and close the recirculated air inlet 44 / 44a) (1006). This pressurizes the enclosed space S (i.e., increases the pressure within the enclosed space S) and breaks down any dust that may have accumulated within the system 1-10 (e.g., within the enclosed space S, the ductwork, the return air unit N or NR, or the air outlet unit U or UM). A predetermined period of time may be allowed for this process. The predetermined period of time may be configurable. A pressure control function (1007) is executed, whereby the controller 11 commands the motors of the air pressurizer 16 / 16a and / or blower 16b to adjust their speeds to reach and then maintain the setpoint pressure (i.e., a predetermined differential pressure value) while gradually moving the door 48 / 48b to open the recirculated air inlet (1008), thereby increasing the size of the opening of the recirculated air inlet 44 / 44a (and decreasing the size of the opening of the fresh air inlet 42 / 42a). These actions include decreasing the size of the fresh air inlet 42 / 42a, which necessitates an increase in the speed of the air pressurizer 16 / 16a and / or blower 16b motors. This continues until the increase in motor speed required to maintain the setpoint pressure is no longer proportional to the increase in recirculated air flow R. If a change in the position of the door 48 / 48b causes a non-proportional increase in the speed of the air pressurizer 16 / 16a and / or blower 16b motor, the controller 11 stops adjusting and maintains the optimized settings for the air pressurizer 16 / 16a and / or blower 16b motor speed and the door 48 / 48b position. This relationship can be defined, for example, as when an x% change in recirculated air flow requires a non-proportional increase in the air pressurizer 16 / 16a and / or blower motor to maintain the pressure at a predetermined value or within a predetermined range of values, where x is a predetermined adjustment step size. The predetermined adjustment step size x is determined experimentally.The predetermined adjustment step size x is desirably large enough to allow the system to quickly converge to a balanced airflow ratio between fresh and recirculated air, but small enough to avoid the risk of overshooting the optimal operating solution. Experimental determination indicates that the predetermined adjustment step size x is approximately a 1.5-degree change in the position of the door 48 / 48b of the airflow distribution balancer 14#. The cost function relationship controlling how the air compressor 16 / 16a or blower 16b motor and the airflow distribution balancer 14# change is described by the more general terms α, β, and δ. Thus, FIG. 25B shows that if the change in the speed of the air compressor 16 / 16a and / or blower 16b motor is greater than α% of the change in recirculated airflow rate (Airflow_R) (step 1010), the resulting area size of the opening of the recirculated air inlet 42 / 42a of the airflow distribution balancer 14# will decrease by βx% (1011). The reduction (1011) in the area size of the opening of the recirculated air inlet 42 / 42a of the air flow distribution balancer 14# continues until the change in speed of the air compressor 16 / 16a and / or blower 16b motor required for operation (1012) of the air compressor 16 / 16a and / or blower 16b motor is less than δ% of the change in recirculated air flow rate (Airflow_R) (1013).

[0233] This operation is represented in FIG. 25B by two loops, the first including 1008, 1009 and 1010, and the second including 1011, 1012 and 1013.

[0234] 25B , the recirculated airflow rate (Airflow_R) is checked, represented by 1010 (in the first loop) and 1013 (in the second loop). Due to the geometry of the airflow distribution balancer 14#, the change in the restriction of the recirculated airflow R is different for each step. The change in airflow is physically checked and compared to the change in motor speed (performed to maintain the setpoint pressure). In the first loop (including 1008, 1009, and 1010), the airflow distribution balancer 14# takes relatively large steps to increase the recirculated airflow R until steady-state operation is exceeded. In the second loop (including 1011, 1012, and 1013), the airflow distribution balancer 14# takes relatively small steps, moving the door 48 / 48b in the opposite direction to decrease the recirculated airflow R. The process performed by the first and second loops thereby progresses toward the desired steady-state operation. The objective is to find the point at which the motor has to make a larger adjustment for the same change in recirculation airflow R.

[0235] At the end of the calibration process, the system state is saved in memory, e.g., non-volatile memory, for use in the cost function (to compare the current pressurizer speed with the saved speed, Speed_F_Saved), and for returning to that system state after a power cycle (1014). The calibration function is then terminated (1015).

[0236] Once calibrated, the system goes into a loop checking sensor measurements, and if the air quality values ​​fall outside the set thresholds, it responds by adjusting the air pressurizer 16 / 16a / blower 16b motor speed to maintain the setpoint pressure, and finally, when the pressure control loop makes a significant change to the air pressurizer 16 / 16a / blower 16b motor speed, it adjusts the position of the air flow distribution balancer 14# door 48 / 48b to compensate (by reducing or adding restriction to the fresh air flow F path).

[0237] Returning to Figure 25A, if the calibration check (1003) indicates that calibration is not required, the system process bypasses the calibration function and instead uses the previously stored system state to restore the system state from memory (1016). Whether the system process undergoes calibration or bypasses the calibration function, the system process then moves to an air quality check (1017).

[0238] Air quality check (including flush and scrub modes) The air quality check (1017) is shown separately in Figure 25C. When an air quality check begins (1018), the first action is to save the current system state to memory (1019) and receive air quality data (e.g., CO2, other undesirable gases, particulates, but not pressure) from the sensors 12 (1020). The data from the sensors 12 is used to check if there is a violation, for example, if the measurement is outside its set threshold. This is represented by 1021 for an internal violation (i.e., a violation inside the enclosed space S) and by 1022 for an external violation (i.e., a violation outside the enclosed space S). If an exceedance is detected, the current state of the system (i.e., air pressurizer 16 / 16a / blower 16b motor speed and air flow distribution balancer 14# door 48 / 48b position) is saved to memory, and the system process remains in the air quality check function, responding to the detected exceedance (and other exceedances, if detected) before restoring the system to its original state (represented by 1023). The air quality check then ends (represented by 1024), and the system process returns to normal system operation (shown in FIG. 25A).

[0239] Air Quality Check - Detailed Explanation 25C , 1021 represents the controller 11 receiving input signals from the sensors 12 monitoring for internal exceedances. If none of the sensors 12 sense that any of the monitored internal environmental parameters have exceeded a predetermined value or range of values, the operational process proceeds along the “No” trajectory shown in FIG. 25C . This process trajectory may also monitor environmental parameters external to the enclosed space S, as represented by 1022 in FIG. 25C . In that regard, suitable sensors 12 may be provided to monitor environmental parameters outside the enclosed space S. Such sensors 12 typically include one or more CO2 sensors 22 and / or gas sensors 26. However, one or more dust sensors 20 may also be included. If none of the sensors 12 sense that any of the monitored external environmental parameters have exceeded a predetermined value or range of values, the operational process proceeds along the “No” trajectory, restoring the system to its original state (1023), and then terminating the air quality check (1024), as previously described herein.

[0240] If any of the sensors 12 sense that one of the monitored environmental parameters exceeds a predetermined value or a predetermined range of values, the operational process proceeds along the associated "Yes" trajectory shown in FIG. 25C, as further described herein. This process trajectory includes actions taken in response to whether any of the sensors 12 sense that an internal exceedance has occurred (1021) or whether an external gas exceedance has occurred (1022, 1027). An internal exceedance can be an excessive level of an undesirable gas (e.g., CO or other undesirable gas) within the enclosed space S (internal gas or CO exceedance 1025) or an excessive level of particulates within the enclosed space S (internal particulate exceedance 1026). An external gas exceedance can be an excessive level of an undesirable gas outside the enclosed space S (1022, 1027).

[0241] 25C includes an operational process for system response when an undesirable (e.g., dangerous) gas is detected. The system response can differ depending on whether the system has an activated carbon filter in the fresh air path. For example, if the system has an activated carbon filter and an excessive level of undesirable gas is sensed externally (i.e., outside the enclosed space S), the system can operate normally. The table below summarizes the system response to various internal and / or external exceedance scenarios, and whether the system has the appropriate filter.

[0242] [Table 1]

[0243] Important responses of the system shown in FIG. 25C include the responses described below, which are explained with reference to the eight cells A1-D2 of the table. If there is an internal gas or CO2 excess (1025), the system checks for an external gas excess (1027). If data received by the controller 11 from the associated sensor 12 indicates that there is no external gas excess, the system activates the flush mode (1028). In this situation, the flush mode is activated regardless of whether the system has gas filtration installed (i.e., whether the system has an activated carbon filter in the fresh air flow path or not) [table, cell B1—filter and cell B2—no filter]. This is because, without an external gas excess, the external air does not contain excessive levels of undesirable gases, and therefore, the flush mode can be activated to draw fresh air into the enclosed space S regardless of whether the system has a filter suitable for gas filtration or not. This is represented in FIG. 25C by the “No” process trajectory leading to the “Flush” mode 1028.

[0244] If there is an internal gas or CO2 excess (1025) and data received by the controller 11 from the associated sensor 12 indicates that there is also an external gas excess, the system will initiate a flush mode (1028) [table cell A1]. This is represented in FIG. 25C by the "Yes" process trajectory that leads from Check installed gas filtration (1029) to Flush mode 1028. With appropriate filters installed in the system, air drawn in from outside the enclosed space S is filtered to remove undesirable gases before being delivered to the enclosed space S.

[0245] In Flush Mode 1028, the system maximizes fresh air flow, thereby diluting undesirable gases with filtered fresh air. Flush Mode replaces the air inside the enclosed space S with air outside the enclosed space S as quickly as possible. The presence of an accessory blower and / or bypass valve 79 / 79a in the system does not affect the operation of Flush Mode. Flush Mode is used to respond to all cases where there are high levels of CO2 and other undesirable gases inside the enclosure. Flush Mode also responds to an excess of gas inside the enclosure if gas filtration is installed at the fresh air intake. The controller 11 increases the speed of the fresh air pressurizer / blower 16 / 16a motor to 100% speed and fully opens the fresh air intake using door 48 / 48b of the air flow distribution balancer 14#.

[0246] If the system does not have an activated carbon filter and both inside and outside undesirable gas levels are sensed to be excessive, the system issues an alarm (step 1030). This is represented in FIG. 25C by the "No" process path leading from Check Gas Filtration Installed (1029) to Alarm 1030. Alarm 1030 notifies personnel of the danger so that they can take appropriate action. In such a situation, for example, appropriate action may include relocating the confined space S (if the confined space is a vehicle cabin) to a location free of external gas excesses so that a flush mode may be activated. Note, however, that if the confined space is likely to operate in a location where it may encounter external gas excesses, appropriate filters should be installed in the system, as described previously herein.

[0247] If there is no internal gas or CO2 excess (1025) and data received by the controller 11 from the sensor 12 indicates there is an external gas excess (1022), FIG. 25C shows two process trajectories leading from Check Gas Filtration 1031: one with a filter installed and one without a filter installed. If the system has an appropriate filter installed, the process follows the "Yes" trajectory to Restore State 1023 [table cell D1] and then to End 1024. If the system does not have an appropriate filter installed, the process follows the "No" trajectory of FIG. 25C to Recirculate 100% (1032) [table cell D2]. With 100% recirculation airflow R (1032), fresh airflow F is not drawn into the airflow distribution balancer 14#. This is done to prevent external air (with a gas excess) from being drawn into the enclosed space S by the pressurizer 16 / 16a. When the system operates with 100% recirculation airflow R, the CO2 levels within the enclosed space S will rise relatively quickly. Therefore, an alarm 1030 is issued to alert the operator to the potential risk of elevated CO2 levels remaining within the enclosed space S.

[0248] When operating with 100% recirculated air flow R (as described previously herein), door 48 / 48b also provides a physical boundary to fresh air inlet 42 / 42a, allowing for shutting off of fresh air flow F (to air flow distribution balancer 14#), for example, if the air quality outside confined space S does not meet a predetermined quality level. For example, if an implementation of the system does not include activated carbon filter 31a for filtering undesirable gases (e.g., H2S, SO2, and / or refrigerant gases such as R-1234YF), door 48 / 48b can be moved such that fresh air flow F is reduced or shut off, thereby reducing health risks to personnel within confined space S.

[0249] Figure 25C also includes an operational process for the system response when excessive levels of particulates (internal particulates exceedance 1026) are detected within the enclosed space S. This is identified in Figure 25C as "scrub" mode 1033. In scrub mode 1033, excessive dust (i.e., particulates) levels within the enclosed space S are reduced.

[0250] Scrub mode 1033 is shown separately in Figure 25D. When scrub mode (1033) begins (1034), controller 11 commands all motors in recirculated airflow R to run at 100% speed (1035) and opens the recirculated air inlets 100% (1036), thereby increasing the recirculated air flow rate as much as possible. If an accessory blower with a bypass valve is present (Embodiments 3-8), the bypass is fully opened (1037, 1038). However, it may be necessary to maintain some pressure in enclosed space S during this process. Thus, scrub mode includes a pressure check 1039 that causes the controller 11 to move the doors 48 / 48b of the airflow distribution balancer 14# to increase the opening of the fresh air intake (i.e., decrease the opening of the recirculated air inlet 1039) until the pressure in the enclosed space S exceeds a configurable "scrub pressure" threshold ("Pressure_S"), as shown at 1040. For example, the value of Pressure_S may be set to 20 Pa. Scrub mode then ends (1041).

[0251] The scrub mode 1033 removes dust particles (i.e., fine particles) from the enclosed space S, thereby cleaning the enclosed space S. Actions described herein can be taken to increase the recirculated airflow R, such as one or more of increasing the speed of the motor of the blower B (thereby increasing the rotational speed of the associated fan or impeller), increasing the speed of the motor of the air compressor 16 / 16a (thereby increasing the rotational speed of the associated fan or impeller), opening the bypass valve 79 / 79a in systems 3-10 having the bypass valve 79 / 79a, and adjusting the opening of the door 48 / 48b to increase the recirculated airflow through the airflow distribution balancer 14#. The actions taken to increase the recirculated airflow R may be selected to achieve the desired operation of a particular system.

[0252] Pressure Control Returning to FIG. 25A, the next step shown in FIG. 25A is pressure control 1042. Pressure control operates to adjust the fresh air pressurizer / blower motor speed to maintain the setpoint pressure. As the filter becomes clogged with particulates, it becomes more restrictive to airflow and requires more work to push air through the filter (e.g., increasing the motor speed for the same airflow). As the seal of the enclosed space S (which seals the enclosed space S from the outside) deteriorates over time, leakage from the enclosed space S increases. Both result in a drop in pressure within the enclosed space S, requiring the system to adjust to maintain the pressure. When the filter is changed or the seal is repaired / replaced, the pressure within the enclosed space S will increase (for the same motor speed) and the system will again need to adjust to maintain the setpoint pressure.

[0253] Pressure control may be a PID (proportional-integral-derivative) control process used to adjust the fresh air pressurizer / blower motor speed to achieve a setpoint pressure. The PID controller can also be used to adjust the position of the door 48 / 48b of the air distribution balancer 14# to achieve the setpoint pressure. This is also done within the pressure control loop. The pressure control loop also recognizes zero (0 Pa) pressure in the enclosed space S as an open door / window and enters a fault state until some pressure is restored to the enclosed space (i.e., the door / window is closed again). This is because an enclosed space with a significant leak such as an open door or window cannot be pressurized, so the system "waits" until it can operate normally again.

[0254] Cost function Cost function 1044 is the final process action shown in FIG. 25A. Cost function 1044 is shown separately in FIG. 26, starting at 1045. The purpose of the cost function is to check whether operation of the pressure control function over time has caused the air pressurizer / blower motor speed to move significantly (called drift) from the optimal value found during the calibration process. Using the pressurizer / blower motor to maintain the setpoint pressure after calibration means that the motor speed will increase as the seals clog or deteriorate while the doors 48 / 48b of the air flow distribution balancer 14# remain fixed. The cost function allows the current motor speed to be compared to the motor speed when the doors 48 / 48b of the air flow distribution balancer 14# were last adjusted. (The doors 48 / 48b are initially adjusted during calibration.) If the motor speed has drifted significantly, the system moves the door 48 / 48b to decrease the restriction to the fresh air inlet 42 / 42a until the motor speed (adjusted to maintain the setpoint pressure) is somewhere between the two compared speeds. (Experimentally, this value was found to be halfway between the two values.) This ensures that both the door 48 / 48b and the air pressurization motor are used to compensate for the clogged filter. Decreasing the restriction of the fresh air inlet 42 / 42a increases the restriction of the recirculated air inlet 44 / 44a, decreasing the recirculated air flow rate. The effect of the cost function is that if the recirculated air flow rate (Airflow_R) is already at or near the set minimum value (1046), the door 48 / 48b will not be moved. It also checks whether the motor speed is already near the set maximum value (1047). If both cases are true, it issues an alert to check the filters and seals (1048) and proceeds to end 1049. If the recirculated air flow rate is not at or near the set minimum, the process trajectory proceeds to 1050 and reduces the recirculated air flow rate using pressure control (1051).

[0255] Before ending at 1049, the cost function saves the new motor speed and door position to non-volatile memory (as shown at 1055), so that the system can return to this state rather than a calibrated state after being power-cycled. In Figure 26, the check is to calculate whether the current speed of the motor (Speed_F) is greater than the sum of the value saved from calibration (Speed_F_saved) and the set drift value (Drift_F), as shown at 1052. If so, the system enters the cost function process and adjusts the door 48 / 48b of the air flow distributor 14# until the motor speed required to maintain pressure is reduced to a level lower than the set drift value while remaining greater than the saved value (Speed_F_saved). The level is expressed as "Speed_F > (Speed_F_Saved + δDrift_F)". Otherwise (i.e., Speed_F < Speed_F_Saved (1053)), the recirculated air is increased (1054) and the process path returns to pressure control (1051).

[0256] In the above example, the position of the door 48 / 48b is fixed after calibration and adjusted only when the cost function is triggered. Alternatively, the system may be used in the reverse manner, in which case the motor speed of the fresh air pressurizer / blower is fixed and the air flow distributor 14# is used to maintain the pressure level inside the housing until the cost function is triggered, and the motor speed is adjusted to compensate for significant movement of the door. However, usually, it is typically preferred to first change the motor speed of the air pressurizer 16 / 16a because it is quicker and continuous to change the motor speed of the air pressurizer 16 / 16a.

[0257] Air flow In the first, second, third and sixth embodiment systems 1, 1b, 2, 3, 6, the airflow generator is in the form of air compressor 16 (systems 1, 1b and 3) or 16a (systems 2 and 6) located downstream of the airflow distribution balancer (and upstream of the enclosed space S). Air compressor 16 or 16a generates a fresh air flow F and a recirculated air flow R. In systems 3 and 6, blower B also generates a recirculated air flow R.

[0258] In the ninth and tenth embodiment systems 9 and 10, an airflow generator in the form of a large capacity blower 16b is located downstream of the airflow distribution balancer (and upstream of the enclosed space S), and the large capacity blower 16b generates a fresh air flow F and a recirculated air flow R.

[0259] In the fourth, fifth and seventh embodiments, Systems 4, 5 and 7, the air flow generator is in the form of air compressor 16 (Systems 4 and 5) or 16a (System 7) and is located upstream of the air flow distribution balancer (and upstream of the enclosed space S), with air compressor 16 or 16a generating fresh air flow F and blower B generating recirculated air flow R.

[0260] In the eighth embodiment of system 8, an air flow generator in the form of an air compressor 16 is located downstream of the first air flow distribution balancer (and upstream of the enclosed space S) that controls the fresh air flow F, with the air compressor 16 generating the fresh air flow F and the blower B generating the recirculated air flow R.

[0261] Features Various features and combinations of features disclosed herein are described in the following paragraphs.

[0262] A system for monitoring and controlling air quality in enclosed spaces. Air flow distribution balancer The air flow distribution balancer may be a component of a system for monitoring and controlling air quality in an enclosed space.

[0263] A system for monitoring and controlling air quality in an enclosed space, comprising: A controller; one or more sensors for monitoring one or more environmental parameters inside the enclosed space; at least one air flow distribution balancer for receiving a first air flow of external air from outside the enclosed space and a second air flow of internal air from inside the enclosed space; an air flow generator that generates at least a first air flow of external air; The controller and the one or more sensors are in operative communication and, in use, the controller may receive one or more input signals from the one or more sensors and, in response to the one or more input signals, the controller may generate one or more output signals that are sent to the air flow distribution balancer and / or air flow generator to control operation of the air flow distribution balancer and / or air flow generator by adjusting the volume of external air and / or the volume of internal air delivered to the enclosed space, thereby controlling one or more environmental parameters related to air quality inside the enclosed space.

[0264] The air flow distribution balancer comprises at least one inlet for air to enter the air flow distribution balancer as an inlet airflow and an outlet for air to exit the air flow distribution balancer as an outlet airflow.

[0265] The airflow distribution balancer includes a chamber that receives air that enters the airflow distribution balancer through at least one inlet. The air flow distribution balancer includes at least one door movable to selected positions, the at least one entrance being fully closed when the at least one door is in a first position, fully open when the at least one door is in a second position, and partially open and partially closed when the at least one door is in an intermediate position between the first and second positions.

[0266] In use, when the at least one door is in the first position, air cannot flow through the at least one inlet, such that the at least one inlet is fully closed, and when the at least one door is in the second or intermediate position, air can flow into the chamber through the at least one inlet and out the outlet, such that the at least one inlet is fully open or at least partially open, respectively.

[0267] The air flow distribution balancer includes at least one motor, and the at least one door and the at least one motor are operatively connected such that the at least one motor is operable to move the at least one door.

[0268] The at least one motor is operable to move the at least one door in response to a signal received from the controller. The airflow distribution balancer includes a first inlet, a second inlet, and an outlet, wherein the first inlet and the second inlet each receive an inlet airflow.

[0269] The first inlet receives a first air flow of external air from outside the enclosed space, and the second inlet receives a second air flow of internal air from within the enclosed space. The outlet airflow exits the airflow distribution balancer through an outlet.

[0270] The first and second entrances are provided with respective doors as described above that are movable to selected positions as previously described herein. The air flow distribution balancer includes first and second motors, and each door and the first and second motors are operatively connected such that the first and second motors are operable to move the respective doors.

[0271] The system includes a first airflow distribution balancer that receives a first airflow of external air and a second airflow distribution balancer that receives a second airflow of internal air. A first bypass valve allows a portion of the air from the enclosed space to return to the enclosed space instead of entering the second air stream.

[0272] A first filter filters the air before a portion of the air is returned to the enclosed space via a first bypass valve. A second bypass valve directs a portion of the air in the outlet air stream into the enclosed space.

[0273] A second filter filters the air before directing a portion of the air through a second bypass valve into the enclosed space. The airflow generator is positioned so that it can draw air from at least outside the enclosed space and direct the air into the enclosed space.

[0274] The airflow generator is located outside the enclosed space. In one or more other embodiments, the airflow generator is located inside the enclosed space. Air passing through the airflow generator is directed into the enclosed space.

[0275] The system includes a duct for the passage of airflow through the system. The airflow generator includes an air pressurizer. The airflow generator includes a blower.

[0276] Depending on the particular implementation of the system, the airflow generator may be in the form of an air pressurizer or a blower. The blower is provided as a high capacity blower.

[0277] The one or more sensors may include one or more of: at least one pressure sensor for sensing pressure inside and outside the enclosed space (i.e., differential pressure sensing) or inside the enclosed space; at least one dust sensor for sensing the presence of dust particles in the enclosed space; at least one CO2 sensor for sensing the presence of CO2 in the enclosed space; at least one airflow sensor for sensing air flow; and / or at least one gas sensor.

[0278] The one or more sensors include at least one pressure sensor. The at least one gas sensor may include one or more gas sensors that sense the presence of a gas, such as, for example, hydrogen sulfide (H2S), sulfur dioxide (SO2), and / or a refrigerant gas, such as, for example, R-1234YF.

[0279] The system includes an air precleaner for pre-cleaning air received from outside the enclosed space before the air enters the at least one inlet of the air flow distribution balancer. The system includes at least one particulate filter for filtering particulate matter from at least a first air flow of outside air.

[0280] At least one particulate filter is provided as a separate filter. At least one particulate filter is provided within the air compressor. The system further comprises at least one activated carbon filter for filtering undesirable gases from at least the first air flow and / or the outlet air flow.

[0281] At least one particulate filter is provided upstream of the activated carbon filter. Air flow distribution balancer a casing having at least a first inlet and an outlet; a chamber within the casing; at least one door movable to selected positions, the at least one entrance being fully closed when the at least one door is in a first position, fully open when the at least one door is in a second position, and partially open and partially closed when the at least one door is in an intermediate position between the first and second positions; In use, when the at least one door is in the first position, air cannot flow through the at least one inlet, such that the at least one inlet is fully closed, and when the at least one door is in the second or intermediate position, air can flow into the chamber through the at least one inlet and out the outlet, such that the at least one inlet is fully open or at least partially open.

[0282] The air flow distribution balancer further comprises at least one motor, and the at least one door and the at least one motor are operatively connected such that the at least one motor is operable to move the at least one door.

[0283] The airflow distribution balancer includes a first inlet, a second inlet, and an outlet. The first and second entrances are provided with respective doors as described above that are movable to selected positions as previously described herein.

[0284] The air flow distribution balancer includes first and second motors, and each door and the first and second motors are operatively connected such that the first and second motors are operable to move the respective doors.

[0285] A method for monitoring and controlling air quality in an enclosed space, comprising: monitoring one or more environmental parameters inside the enclosed space; generating at least a first air flow of external air from outside the enclosed space with an air flow generator; receiving a first external airflow and a second internal airflow from inside the enclosed space at at least one airflow distribution balancer; delivering air from the at least one air flow distribution balancer to the enclosed space with an outlet air flow; generating one or more input signals indicative of one or more environmental parameters inside the enclosed space; generating one or more output signals in response to one or more input signals; and sending one or more output signals to the airflow distribution balancer and / or the airflow generator to control operation of the airflow distribution balancer and / or the airflow generator by adjusting the volume of external air and / or the volume of internal air delivered to the enclosed space, thereby controlling one or more environmental parameters related to air quality inside the enclosed space.

[0286] In this method, receiving a first air flow of external air and a second air flow of internal air from inside the enclosed space at at least one air flow distribution balancer includes receiving the first air flow of external air and the second air flow of internal air at a single air flow distribution balancer.

[0287] In this method, receiving a first air flow of external air and a second air flow of internal air from inside the enclosed space at at least one air flow distribution balancer includes receiving the first air flow of external air at a first air flow distribution balancer and receiving the second air flow of internal air at a second air flow distribution balancer.

[0288] The method further includes returning the portion of the air from the enclosed space through the first bypass valve to the enclosed space rather than allowing the portion of the air from the enclosed space to enter the second air stream. The method further includes filtering the air before returning a portion of the air to the enclosed space through the first bypass valve.

[0289] The method further includes directing a portion of the air in the outlet air stream through a second bypass valve into the enclosed space. The method further includes filtering the air before directing a portion of the air through a second bypass valve and into the enclosed space.

[0290] While one or more preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to these particular embodiments and may be embodied in other ways, as will be apparent to those skilled in the art.

[0291] Each individual feature, structure, or characteristic of each aspect or embodiment disclosed herein may be combined with any or all of the features, structures, or characteristics of the other aspects or embodiments. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more aspects or embodiments of the present disclosure.

[0292] Modifications and variations that will be apparent to a person skilled in the art are deemed to be within the scope of the present invention.

Claims

1. A system for monitoring and controlling air quality in a closed space, Controller and One or more sensors for monitoring one or more environmental parameters inside the enclosed space, An airflow distribution balancer for receiving a first airflow of external air from outside the enclosed space and a second airflow of internal air from inside the enclosed space, wherein the at least one airflow distribution balancer is At least one inlet for air to enter the airflow distribution balancer as an inlet airflow, A chamber that receives air entering the airflow distribution balancer through at least one of the inlets, An outlet for air to exit the airflow distribution balancer as an outlet airflow, A door that is movable to a selected position, wherein when the front door is in a first position, the at least one entrance is completely closed; when the door is in a second position, it is completely open; and when the door is in an intermediate position between the first and second positions, the at least one entrance is partially open and partially closed. Equipped with an airflow distribution balancer, An airflow generator that generates at least the first airflow of external air and Equipped with, A system in which the controller and the one or more sensors are in an operable communication state, and when in use, the controller is configured to receive one or more input signals from the one or more sensors, and the controller is configured to generate one or more output signals in response to the one or more input signals, and the one or more output signals are transmitted to at least one of the airflow distribution balancer and the airflow generator to control one or more environmental parameters relating to the air quality inside the enclosed space by adjusting at least one of the volume of external air and the volume of internal air delivered to the enclosed space, respectively, in order to control the operation of at least one of the airflow distribution balancer and the airflow generator.

2. The system according to claim 1, wherein when the at least one door is in a first position during use, air cannot flow through the at least one inlet and the at least one inlet is completely closed, and when the at least one door is in a second or intermediate position, air can flow into the chamber through the at least one inlet and exit through the outlet and the at least one inlet is fully open or at least partially open.

3. The system according to claim 2, wherein the airflow distribution balancer further comprises a motor, and the door and the motor are operably connected such that the motor is operable to move the door.

4. The system according to claim 3, wherein the motor is operable to move the door in response to a signal received from the controller.

5. The system according to claim 1, wherein the airflow distribution balancer comprises a first inlet for receiving the first airflow, a second inlet for receiving the second airflow, and an outlet for the outlet airflow.

6. The system according to claim 1 is a system comprising a first airflow distribution balancer that receives the first airflow of external air, and a second airflow distribution balancer that receives the second airflow of internal air.

7. The system according to claim 1, further comprising a first bypass valve that allows a portion of the air to return to the closed space from the closed space instead of the second airflow entering.

8. The system according to claim 7, further comprising a first filter that filters the air before a portion of the air is returned to the closed space via the first bypass valve.

9. The system according to claim 7 further comprises a second bypass valve for directing a portion of the air in the outlet airflow into the closed space.

10. The system according to claim 9 further comprises a second filter for filtering the air before directing the portion of the air into the enclosed space via the second bypass valve.

11. The system according to any one of claims 1 to 10, wherein the airflow generator is arranged to draw in air from at least outside the enclosed space and direct the air into the enclosed space.

12. The system according to any one of claims 1 to 10, wherein the airflow generator is located outside the enclosed space.

13. The system according to any one of claims 1 to 10, wherein the airflow generator is located inside the enclosed space.

14. The system according to any one of claims 1 to 10, wherein the airflow generator includes an air pressurizer.

15. The system according to any one of claims 1 to 10, wherein the airflow generator includes a blower.

16. The one or more sensors include at least one pressure sensor that senses the pressure inside and outside the enclosed space, or the pressure inside the enclosed space, at least one dust sensor that senses the presence of dust or dust particles in the enclosed space, and CO2 in the enclosed space. ２ At least one CO that can sense the presence of ２ The system according to any one of claims 1 to 10, comprising one or more sensors, including a sensor, at least one airflow sensor for sensing airflow, and / or at least one gas sensor.

17. The system according to claim 16, wherein the at least one gas sensor includes one or more gas sensors that detect the presence of one or more gases.

18. The one or more gases mentioned above are hydrogen sulfide (H ２ S), sulfur dioxide (SO ２ ) and / or the system according to claim 17, comprising a refrigerant gas.

19. The system according to claim 18, wherein the refrigerant gas includes R-1234YF.

20. The system according to any one of claims 1 to 10, further comprising an air pre-cleaner for pre-cleaning air received from outside the enclosed space before air enters the at least one inlet of the airflow distribution balancer.

21. The system according to claim 14, further comprising at least one particulate filter for filtering particulate matter from the first airflow of at least external air.

22. The system according to claim 21, wherein the at least one particulate filter is provided as a separate filter.

23. The system according to claim 21, wherein the at least one particulate filter is provided within the air pressurizer.

24. The system according to any one of claims 1 to 10, further comprising at least one activated carbon filter for filtering out undesirable gases from at least the first airflow and / or the outlet airflow.

25. The system according to claim 24, wherein at least one particulate filter is provided upstream of the activated carbon filter.

26. It is an airflow distribution balancer, A casing having at least one first inlet and outlet, The chamber inside the casing, A door that is movable to a selected position, wherein when the door is in a first position, the at least one entrance is completely closed; when the door is in a second position, the at least one entrance is completely open; and when the door is in an intermediate position between the first and second positions, the at least one entrance is partially open and partially closed. Equipped with, An airflow distribution balancer, wherein when the at least one door is in the first position during use, air cannot flow through the at least one inlet and the at least one inlet is completely closed, and when the at least one door is in the second position or an intermediate position, air can flow through the at least one inlet into the chamber and out of the outlet and the at least one inlet is fully open or at least partially open.

27. The airflow distribution balancer according to claim 26 further comprises a motor, wherein the door and the motor are operably connected such that the motor is operable to move the door.

28. The airflow distribution balancer according to claim 26 or 27, further comprising a second inlet.

29. The airflow distribution balancer according to claim 28, wherein the first inlet and the second inlet are each provided with the door, which is movable to a selected position.

30. A method for monitoring and controlling air quality in a closed space, Monitoring one or more environmental parameters inside the enclosed space, The airflow generator generates at least a first airflow of outside air from outside the enclosed space, In at least one airflow distribution balancer, the first airflow of external air and the second airflow of internal air are received from inside the enclosed space. The air from at least one of the airflow distribution balancers is sent into the enclosed space by the outlet airflow, To generate one or more input signals that represent one or more environmental parameters inside the enclosed space, To generate one or more output signals in response to one or more input signals, Transmitting one or more output signals to at least one of the airflow distribution balancer and the airflow generator, thereby controlling one or more environmental parameters relating to the air quality inside the enclosed space by controlling the operation of at least one of the airflow distribution balancer and the airflow generator by adjusting at least one of the volume of external air and the volume of internal air delivered to the enclosed space. A method that includes this.

31. The method according to claim 30, wherein the at least one airflow distribution balancer receives the first airflow of external air and the second airflow of internal air from inside the enclosed space, A method comprising receiving a first airflow of external air and a second airflow of internal air in a single airflow distribution balancer.

32. The method according to claim 30, wherein the at least one airflow distribution balancer receives the first airflow of external air and the second airflow of internal air from inside the enclosed space, A method comprising receiving the first airflow of external air in a first airflow distribution balancer, and receiving the second airflow of internal air in a second airflow distribution balancer.

33. A method according to any one of claims 30 to 32, further comprising returning the portion of the air to the closed space via a first bypass valve, rather than allowing a portion of the air from the closed space to enter the second airflow.

34. A method according to claim 33, further comprising filtering the air before returning the portion of the air to the enclosed space through the first bypass valve.

35. The method according to claim 33 further comprises directing a portion of the air in the outlet airflow into the closed space via a second bypass valve.

36. The method according to claim 35 further comprises filtering the air before directing the portion of the air into the enclosed space through the second bypass valve.

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