Temperature sensor autoconfiguration in HVAC systems

Abstract

An indoor unit (IDU) for a heat pump conditioning air of a building is disclosed. The IDU includes an intake port for return air. An indoor coil is air coupled with the intake port. When installed according to factory presents, a first temperature sensor is positioned between the intake port and the indoor coil. A second temperature sensor is positioned at a location opposite to the first temperature sensor and downstream to the indoor coil. A control unit is configured to monitor temperatures from the first temperature sensor and the second temperature sensor to compare temperatures. The control unit uses a control algorithm to identify direction of airflow and confirm proper installation location of the first and second temperature sensor. Depending on the airflow direction, the first and second temperature sensors may be algorithmically switched.

Description

BACKGROUND

[0001] This disclosure generally relates to a heat pump or air conditioner and, not by way of limitation, sensing the temperatures in the heat pump and applying various algorithms with those temperatures.

[0002] Temperature sensing in a heat pump typically involves using a sensor that is installed at an air intake to measure temperature of incoming return air for the indoor unit (IDU) of the heat pump. The temperature sensor facilitates operational adjustments of components, such as compressor and fan based on the detected temperature. During installation, the sensor can be installed incorrectly causing malfunction of the heat pump and unnecessary rework and possible product returns. For example, the sensor needs to be upstream of the coil and may be moved for proper installation.SUMMARY

[0003] In one embodiment, an indoor unit (IDU) for a heat pump conditioning air of a building is disclosed. The IDU includes an intake port for return air from the building. An indoor coil is air coupled with the intake port. When installed according to factory presets, a first temperature sensor is positioned between the intake port and the indoor coil. A second temperature sensor is positioned at a location opposite to the first temperature sensor and downstream to the indoor coil. A control unit is configured to monitor temperatures from the first temperature sensor and the second temperature sensor to compare temperatures. The control unit uses a control algorithm to identify direction of airflow and confirm proper installation location of the first and second temperature sensor. Depending on the airflow direction, the first and second temperature sensors may be algorithmically switched.

[0004] In an embodiment, an indoor unit for a heat pump is disclosed. The indoor unit includes an indoor coil, first and second temperature sensors, and a control unit. The indoor coil is air coupled with an intake port. The first temperature sensor is designed for positioning between the intake port and the indoor coil. The second temperature sensor is designed for positioning downstream to the indoor coil. The control unit is configured to: monitor temperatures from the first temperature sensor and the second temperature sensor, compare temperatures determined by the first temperature sensor and the second temperature sensor, algorithmically determine which of the first or second temperature sensors is upstream of the indoor coil, and control operation of the heat pump according a reading from the first or second temperature sensors that is determined upstream of the indoor coil.

[0005] In another embodiment, an indoor unit for a heat pump that conditions air of a building is disclosed. The indoor unit includes an intake port for return air, an indoor coil air coupled with the intake port, a first temperature sensor designed for positioning between the intake port and the indoor coil when properly installed, a second temperature sensor designed for positioning at a location opposite to the first temperature sensor and downstream of the indoor coil; and a control unit. The control unit is configured to: monitor temperatures from the first temperature sensor and the second temperature sensor, compare temperatures of the first temperature sensor and the second temperature sensor following a predetermined time interval after initialization of the indoor unit, determine a direction of airflow with respect to the first and second temperature sensors, and determine which of the first and second temperature sensors is installed upstream of the indoor coil to sense the return air based on: the direction of airflow, and comparison of the temperatures.

[0006] In yet another embodiment, a method for automatically configuring an indoor unit of a heat pump that conditions air of a building is disclosed. In one step, temperatures from a first temperature sensor and a second temperature sensor are monitored. The first temperature sensor is upstream of an indoor coil when installed in standard orientation. Temperatures determined by the first temperature sensors and the second temperature sensors are compared to determine a temperature differential. A direction of airflow across the indoor coil is determined based upon the temperature differential and a mode of operation of the heat pump. The temperature of the return air is determined based on: the direction of airflow with respect to the first and second temperature sensors, and temperature differential. A correct temperature of the return air is determined based on a mode of operation of the heat pump.

[0007] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various embodiments, are intended for purposes of illustration only and are not intended to necessarily limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure is described in conjunction with the appended figures:

[0009] FIG. 1A shows indoor and outdoor units with their placement for a building;

[0010] FIG. 1B illustrates a schematic view of an indoor unit (IDU) that is part of a heat pump;

[0011] FIGS. 2A to 2D illustrate various installation configurations of the IDU;

[0012] FIG. 3 illustrates a schematic view of an A-coil of the IDU;

[0013] FIG. 4 illustrates a schematic view of an M-coil of the IDU; and

[0014] FIG. 5 illustrates a temperature sensing method for return air coming inside an IDU unit.

[0015] In the appended figures, similar components and / or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a second alphabetical label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.DETAILED DESCRIPTION

[0016] The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

[0017] Referring initially to FIG. 1A, a schematic view of a heat pump system 150 according to an embodiment is shown. The heat pump system 150 shows a building or house 103, and a heat pump divided between an indoor unit (IDU) 100 and an outdoor unit (ODU) 118. A thermostat 138 is connected to the IDU 100 to provide a control interface and remote sensors to allow control of the heat pump system 150 according to occupant preferences.

[0018] The heat pump system 150 provides heating and cooling for the building 103 with optional humidity control. The outdoor temperature and humidity levels play an important role in determining the operation of the heat pump. When these conditions are not favorable, the heat pump system 150 maintains efficiency and comfort. The ODU 118 includes an ODU fan 105, a heat exchanger coil 106, and a compressor 107. The ODU fan 105 is configured to draw outside ambient air into the ODU 118. The ODU fan 105 ensures a continuous and regulated airflow over the heat exchanger coil 106, thereby facilitating heat exchange.

[0019] The heat exchanger coil 106 is disposed within an airflow path created by the ODU fan 105 in airflow communication with an ODU intake 124 of the ODU 118. In heating mode, the heat exchanger coil 106 functions to absorb heat from the air drawn in by the ODU fan 105, thereby heating the refrigerant passing through the heat exchanger coil 106. The heat exchanger coil 106 is airflow connected to the compressor 107. The compressor 107 is configured to compress the refrigerant, thereby raising the temperature and pressure of the refrigerant. The high-pressure refrigerant is then directed to the IDU 100, specifically to an indoor coil 108.

[0020] The IDU 100 includes the indoor coil 108, a control unit 112, and an exit port 116 to condition building 103. In heating mode for the heat pump system 150, the high-pressure refrigerant from the compressor 107 is directed to the indoor coil 108, where it releases its absorbed heat to the air passing over the indoor coil 108. An indoor fan (not shown) is positioned downstream of the indoor coil 108 in this embodiment. The exit port 116 circulates the heated air throughout building 103, ensuring even distribution of warm air to maintain consistent indoor comfort.

[0021] The control unit 112 is configured to receive data from temperature and humidity sensors in the ODU 118, IDU 100 and any thermostat(s) 138 in the building 103 to control operation of the heat pump system 150 to achieve a desired comfort programmed by occupants. Furthermore, control unit 112 also executes a control algorithm to operate the heat pump system 150, identify malfunctions and reprogram when possible, to fix the malfunctions.

[0022] With regard to FIG. 1B, a schematic view of the IDU 100 that is part of a heat pump to provide heat movement as part of a building is illustrated according to an embodiment of the present disclosure. The IDU 100 includes an intake port 102, a first temperature sensor 104, an intake fan 106, an indoor coil 108, a second temperature sensor 110, and a control unit 112. The indoor coil 108 is configured such that the return air flows downwards through the indoor coil 108 with activation of the intake fan 106. In this embodiment, the intake fan 106 is proximate to the intake port 102. In a different embodiment, the intake fan 106 could be placed proximate to the exit port of the IDU or anywhere in between to move airflow throughout the IDU 100.

[0023] The IDU 100 allows determining temperature of airflow using the first and second temperature sensors 104, 110. The IDU 100 uses two temperature sensors 104, 110, where the first temperature sensor 104 is placed in air communication with an intake port 102 and the second temperature sensor 110 is placed at an opposite location that is downstream of the indoor coil 108. A dual-sensor setup ensures accurate measurement of the temperature of airflow. Additionally, an algorithm can be used with two temperature measurements on each side of indoor coil 108 to confirm airflow direction for the particular installation.

[0024] By positioning the two sensors at alternative sides of the indoor coil 108 with respect to the airflow, the IDU 100 can reliably detect temperature variations, providing a comprehensive understanding of the air temperature conditions impacting performance of the IDU 100. As a result, the IDU 100 becomes “error-proof” for the installers regardless of the orientation of the indoor coil 108 during installation. Generally, indoor coil 108 is designed such that airflow direction and refrigerant direction respectively go in their predetermined directions. Installation of the indoor coil 108 backwards with respect to airflow or the coolant loop reversed may cause the IDU 100 to fail in conventional systems. The IDU 100 installation is labor intensive and improper installation of the temperature sensors 104, 110, indoor coil 108 or other components results in unnecessary rework, faulty operation, and / or product returns.

[0025] The intake port 102 is designed to facilitate entry of return or fresh air into the IDU 100. The intake port 102 serves as an initial point of contact for the airflow before it undergoes any conditioning. The intake port 102 is positioned to intake return air entering the IDU 100 and is at the temperature of the external environment, typically, at indoor temperature for the building. After conditioning by the IDU 100, the airstream is pushed into the building through an exit port 116 as supply air.

[0026] The first temperature sensor 104 is positioned in air communication with the intake port 102 and is responsible for measuring the temperature of the incoming return air. The first temperature sensor 104 is positioned proximate and upstream of the indoor coil 108. The first temperature sensor 104 captures real-time temperature of the incoming return air so that the IDU 100 can monitor and adjust the heating or cooling based on the detected temperature of incoming return air with respect to a set point for the desired air temperature at thermostat 138 and / or other sensor inside the building being conditioned. The first temperature sensor 104 is communicatively connected to the control unit 112 via a wired or wireless connection in various embodiments.

[0027] The intake or blower fan 106 is located upstream of the first temperature sensor 104 and serves to draw the return air through the intake port 102 and into the IDU 100. The intake fan 106 draws of airflow through the indoor coil 108 to have heat exchange for raising or lowering the temperature of the airflow. The intake fan 106 is communicatively connected to control unit 112, which regulates the speed and operation of the intake fan 106 based on the temperature data and desired indoor temperature. For instance, control unit 112 increases the fan speed in response to higher return temperatures to enhance cooling of the airstream. In other embodiments, the intake fan 106 can be downstream of the indoor coil 108 or anywhere in the airstream to pull or push airflow through the IDU 100 from the intake port 102 to exit port 116.

[0028] The indoor coil 108 is positioned downstream of the intake fan 106 and serves as the primary heat exchanger for the IDU unit 100. The indoor coil 108 is air coupled with the intake port 102. The indoor coil 108 is configured as an evaporator coil in a cooling mode or as a condenser coil in a heating mode, depending on desired indoor building temperature. The return air passes over the indoor coil 108 and undergoes temperature modification, either by absorbing or releasing heat. The indoor coil 108 is fluidly connected to a refrigerant circuit, allowing for effective heat transfer to the outdoor unit (not shown). For example, in a cooling scenario, the indoor coil 108 absorbs heat from the airstream to cool the return air before it is distributed throughout the building.

[0029] The second temperature sensor 110 is placed on the opposite side of the indoor coil 108 from the first temperature sensor 104 and measures the temperature of the airstream after temperature modification by passing through the indoor coil 108. The location of the second temperature sensor 110 is downstream to the indoor coil 108. The second temperature sensor 110 is connected to control unit 112 in a similar manner to the first temperature sensor 104 to enable continuous temperature measurement. The second temperature sensor 110 provides feedback to control unit 112 for assessing effectiveness of a heat exchange process. For example, a thermocouple or a resistance temperature detector (RTD) serves as the first and / or second temperature sensors 104,110 to deliver precise temperature readings.

[0030] Control unit 112 controls certain functions of the IDU 100. The control unit 112 receives temperature data from both the first temperature sensor 104 and the second temperature sensor 110, analyzes the information, and adjusts the operation of the intake fan 106 and other components of the IDU 100 and heat pump. The control unit 112 monitors temperatures from the first temperature sensor 104 and the second temperature sensor 110 to compare their temperatures for a control algorithm to determine the direction of airflow with respect to the indoor coil 108. The IDU 100 depicts the direction of airflow using arrows in FIG. 1. The control unit 112 determines temperature of the return air after determining the direction of airflow over the indoor coil 108. When the indoor coil 108 is moving heat from the airstream, readings from the first and second temperature sensors 104, 110 allows algorithmically determining a direction of the airstream regarding the indoor coil 108. The temperature of the return air is determined based on a mode of operation of the heat pump.

[0031] When the heat pump is installed and working properly, a higher temperature is measured by the first temperature sensor 104 than lower temperature of the second temperature sensor 110 when the indoor coil 108 is cooling. For example, if the first temperature sensor 104 measures an incoming return air temperature of 85° F. and the second temperature sensor 110, after air passes over the indoor coil 108, measures a temperature of 75° F., the IDU 100 would consider the higher value of 85° F. as the correct return air temperature such that the IDU 100 is installed correctly. Some conventional systems only have a single temperature sensor and when installed on the wrong side of the indoor coil, the heat pump will not operate correctly. With the two temperature sensors affixed to the indoor coil, the temperature gradient between the two could be the inverse of the designed value indicating that the indoor coil needs to be reversed with respect to the airstream.

[0032] A lower temperature determined by the first temperature sensor 104 with respect to the second temperature sensor 110 is indicative of proper operation when in a heating mode for the heat pump. For example, if the first temperature sensor 104 measures the incoming return air temperature at 60° F. and the second temperature sensor 110, after the air has passed over the indoor coil 108, measures a temperature of 70° F., the IDU 100 will consider the lower value of 60° F. as the correct return air temperature. A positive temperature differential is from the heating effect within the heat pump. Should the indoor coil 108 be installed in a different flow orientation, there would not be a positive temperature differential during heating mode. Algorithmically, the first and second temperature sensors 104, 110 can be switched depending on installed flow direction once a negative temperature differential is detected during a heating mode (or a positive temperature differential in a cooling mode).

[0033] In some embodiments, control unit 112 is configured to detect an unanticipated airflow direction across the indoor coil 108 through unique installations that require different airflow orientation. In those cases where the indoor coil 108 is installed in a reversed orientation with respect to the airstream, the temperature sensors 104, 110 could be installed in an unanticipated configuration with respect to the airstream. For example, the control unit 112 may determine little or no temperature differential from readings from the first temperature sensor 104 and the second temperature sensor 110. Specifically, if the first temperature sensor 104 measures a return air temperature of 70° F. and the second temperature sensor 110, after the air has passed over the indoor coil 108, also measures 70° F., the control unit 112 would interpret this as a potential malfunction in the indoor coil 108. The same or similar temperature readings suggest that the indoor coil 108 is not effectively altering the airstream temperature, which indicates a failure in the heating or the cooling process. Control unit 112 can alert the user or maintenance personnel for further investigation.

[0034] In some embodiments, the control unit 112 is configured to compare the temperatures from the first temperature sensor 104 and the second temperature sensor 110 following a pre-defined time interval after an initiation or activation of the heat pump. This could be performed upon installation or with each cold start after a power interruption in various embodiments. For example, upon starting the IDU 100, the control unit 112 is programmed to wait for 10 minutes after activation of the heat pump before comparing the temperature readings. During this pre-defined time interval, the IDU 100 allows time for the indoor coil 108 to reach its operating temperature, the intake fan 106 to activate, and for the airflow temperature to stabilize. After 10 minutes (or some other predetermined interval), the control unit 112 compares the temperature data from the first temperature sensor 104, which measures the incoming return air, and the second temperature sensor 110, which measures the air temperature after passing over the indoor coil 108. The temperature comparison helps in assessing whether the IDU 100 is functioning correctly by determining if there is an expected temperature differential indicative of proper heating or cooling. In some embodiments, this algorithm is only performed at initial install or periodically thereafter.

[0035] The control unit 112 includes a microprocessor or a programmable logic controller (PLC) programmed with algorithms to optimize the heat pump's performance in conjunction with the ODU 118 and possibly other control units. Additionally, control unit 112 is connected to an external system or user interfaces, allowing for remote monitoring and control such as a thermostat 138 or another controller. Various sensors within the building measuring humidity, temperature, etc. could also report to the control unit 112 to allow algorithms to better maintain desired comfort within the building.

[0036] The IDU 100 further includes a refrigerant leak detector that is communicably coupled with the control unit 112. The control unit 112 is further configured to monitor signals from the leak detector and initiate shutdown of the heat pump upon detection of a leak of refrigerant. For example, if the leak detector identifies a drop in refrigerant pressure or detects the presence of refrigerant in areas where it should not be, the leak detector sends a signal to the control unit 112. The control unit 112 interprets this signal as an indication of a refrigerant leak and promptly activates a shutdown procedure to prevent further damage or inefficiency. This involves turning off the compressor and other components to protect the IDU 100 and ensure safety. Various embodiments could also algorithmically detect blockage or founding of the evaporator, slowly eroding performance of the intake fan or blower, air filter replacement / cleaning reminder, etc.

[0037] Referring next to FIGS. 2A-2D, various installation configurations 200-1, 200-2, 200-3, 200-4 of the IDU 100 are illustrated to show different directions of return air flowing through the indoor coil 108. The technician may install the indoor coil 108 with respect to the airflow differently or even improperly. Proper installation has a temperature sensor measuring the return air prior to temperature conditioning by the indoor coil 108. Depending on the installation, the temperature sensor would be moved in conventional installations for IDUs with a single temperature sensor.

[0038] FIG. 2A depicts a horizontal-left installation configuration 200-1 of the IDU 100 where the return air flows horizontally to the right through the indoor coil 108 when properly installed. In the horizontal-left installation 200-1, the air enters the IDU 100 from the left side of the indoor coil 108 and exits to the right side. The first temperature sensor 104 measures the temperature of the return air, while the second temperature sensor 110 records the temperature of the airflow after it has passed over the indoor coil 108. With two temperature sensors 104, 110 both before and after the indoor coil 108 there will always be temperature sensing of the return air.

[0039] FIG. 2B illustrates a horizontal-right installation configuration 200-2 of the IDU 100 where the return air flows horizontally to the left through the indoor coil 108. Here, the air enters the IDU 100 from the right side with respect to the indoor coil 108 and exits to the left side. Here, the second temperature sensor 110 measures the temperature of the incoming air, while the first temperature sensor 104 records the temperature of the air after it has passed over the indoor coil 108. With the installation having reversed airflow, the control unit 112 uses the second temperature sensor 110 to measure the return air to properly operate the heat pump. Through automatic analysis, the airflow direction can be determined to know if the first or second temperature sensor 104, 110 should measure the return air at the inlet.

[0040] FIG. 2C shows an upflow installation configuration 200-3 of the IDU 100 in which the return air flows vertically upwards through the indoor coil 108. In the upflow installation configuration 200-2, the return air enters from below the indoor coil 108 and exits above. The direction of airflow is depicted by arrows. The first temperature sensor 104 is positioned to detect the temperature of the airflow before passing through the indoor coil 108. The second temperature sensor 110 measures the temperature after the air has been conditioned by the indoor coil 108 before exiting the IDU 100 to condition the building.

[0041] FIG. 2D shows a downflow installation configuration 200-4 of the IDU 100 in which the return air flows vertically downwards through the indoor coil 108. The second temperature sensor 104 is above the indoor coil 108 to sense the return air before any temperature differential is applied to the airstream to condition the building. The control unit 112 adapts control algorithms once airflow direction is determined after installation.

[0042] Regardless of installation configuration 200, the control unit 112 can determine the temperature sensor that is upstream of the indoor coil 108. In the embodiments in FIGS. 2B and 2D, For example, the second temperature sensor 110 measures the return air temperature. The temperature sensor after the indoor coil 108 is the first temperature sensor 104 for measuring the airstream as it returns to the building through exit port 116 once the airstream direction is determined. The control unit 112 automatically determines airflow direction with respect to the coil 108 and temperature sensors to configure the control algorithms accordingly.

[0043] Referring to FIG. 3, illustrates a schematic view of an A-coil 300 that serves as the indoor coil of the IDU 100. Although the indoor coil 108 can come in many different configurations, the A-coil 300 cups the airstream while passing it through to modify the temperature. The A-coil 300 is a type of heat exchanger that is air coupled with the intake port 102, allowing return air to flow through A-coil 300 for conditioning. The A-coil 300 is designed with a distinctive A-shape, which enhances its surface area and efficiency of heat exchange. The return air enters the IDU 100 through the intake port 102 and is directed over the A-coil 300 to lower or raise the temperature of the airstream.

[0044] The first temperature sensor 104 is cupped above an entrance 302 of the A-coil 300. This placement allows first temperature sensor 104 to measure the temperature of the return air as it first contacts the A-coil 300, providing an accurate reading of the return air temperature before any heat exchange occurs. The direction of airflow is depicted by arrows.

[0045] The second temperature sensor 110 is positioned at an apex 304 of the A-coil 300. This location is used for measuring the temperature of the airstream after it has passed through and interacted with the A-coil 300 for heat exchange. By positioning the second temperature sensor 110 at apex 304, the control unit 112 captures the temperature of the air that has been conditioned by the A-coil 300, which can be higher or lower depending on the mode of operation (heating or cooling).

[0046] The direction of return air flow through the A-coil 300 can be configured in various ways. Installers may rotate the A-coil 300 with respect to the airstream, to reverse airflow direction from one side to another or vice versa. For example, the air might flow horizontally from left to right, horizontally from right to left, or vertically from bottom to top with the orientation of the A-coil 300 being rotated appropriately. Regardless of the direction of airflow, the placement of the temperature sensors near the entrance 302 and the apex 304 of the A-coil 300 ensures that accurate temperature measurements are obtained to determine the heat transferred to the airstream. The control unit 112 interprets these measurements and makes necessary adjustments to adjust heat pump operation based on the direction of airflow and the thermal performance of the A-coil 300. This flexibility in airflow direction enhances the adaptability of the heat pump to different installation environments and configurations according to installer preference.

[0047] Referring to FIG. 4, illustrates a schematic view of an M-coil 400 that serves as the indoor coil for the IDU 100 as the heat exchanger component. The M-coil 400 is air coupled with the intake port 102, allowing return air thermal conditioning. The direction of airflow is depicted by arrows in the figures. The design of the M-coil 400 includes an M-shaped configuration to increase surface area available for heat exchange and enhances efficiency of the heat pump.

[0048] The first temperature sensor 104 is positioned at the base 402 of the M-coil 400. This location allows the first temperature sensor 104 to measure the temperature of the return air as it first encounters the M-coil 400. By capturing the temperature at this initial point, the first temperature sensor 104 provides an accurate reading of the incoming air before it undergoes any heating or cooling. For example, if the air flows horizontally from left to right through the M-coil 400, the first temperature sensor 104 would be situated at the leftmost point of the indoor coil where the air initially enters.

[0049] The second temperature sensor 110 is positioned at an apex 404 of the M-coil 400. This sensor measures the temperature of the airflow after it has passed through the M-coil 400. Positioned at the top or apex 404, the second temperature sensor 110 captures the conditioned air temperature, which reflects the thermal effect imparted by the indoor coil. This setup allows for an accurate assessment of the temperature change resulting from the heat exchange process. For instance, if the air flows vertically from bottom to top, the second temperature sensor 110 would be located at the upper end of the indoor coil where the air exits. The airstream direction through the M-coil 400 can vary based on installation requirements. It may flow horizontally from left to right, horizontally from right to left, or vertically from bottom to top. The flexible accommodation of airflow direction ensures that the IDU 100 can be adapted to different installation orientations while maintaining accurate temperature measurement. The control unit 112 can reconfigure which is the first or second temperature sensor according to any orientation of the M-coil 400 with respect to the airflow. The control unit 112 interprets the readings from both temperature sensors to assess system performance and make necessary adjustments, ensuring efficient operation regardless of the direction of airflow through the M-coil 400.

[0050] With reference to FIG. 5, a temperature sensing method 500 for controlling IDU 100 according to an embodiment of the present disclosure is illustrated. Some steps of the temperature sensing method 500 may be performed by the IDU 100 by utilizing processing resources in the control unit 112 and / or ODU 118 or thermostat 138. Some embodiments may use processing resources in the cloud with an Internet connection from the building. Initially, it is presumed that the indoor coil 108 is installed to factory preset airstream direction, and the first temperature sensor 104 is upstream to measure a first temperature T1 and the second temperature sensor 110 is downstream to measure a second temperature T2 on opposite sides of the indoor coil 108. With factory presets, it is presumed that the first temperature sensor 104 is upstream of the indoor coil 108 until the algorithm in this temperature sensing method 500 determines otherwise.

[0051] At block 502, the heat pump operation is initialized. This step involves powering on and / or initializing the heat pump including the IDU 100 and beginning its operation. This could be done upon initial installation or later during ongoing operation after installation. The heat pump then begins to monitor and regulate the indoor air temperature according to the setting from a thermostat 138 or mobile app under the control of a user of the building.

[0052] At block 504, the first temperature sensor 104 receives the first temperature (T1) of the return air entering the air intake of the IDU 100. The first temperature sensor measures the temperature of the airstream before it undergoes any conditioning. For instance, in a commercial building, the first temperature sensor 104 might be located near the air intake 102, ensuring accurate measurement of the return air temperature from the building.

[0053] At block 506, the second temperature sensor 110 receives the second temperature (T2) of the airstream after the heat exchange with the indoor coil 108. Similar to the first temperature sensor 104, the second temperature sensor 110 is placed near the indoor coil 108 to provide an additional temperature reading of the airstream.

[0054] At block 508, the control unit 112 checks if a pre-defined time interval has been exceeded. This interval represents the time for the IDU 100 to condition the airstream after startup before testing for a temperature differential over the indoor coil 108. For example, an IDU may have a pre-defined interval of 15 minutes, after which it assumes the airstream should be sufficiently conditioned to measure and compare temperatures effectively. When the time interval has not been exceeded, the IDU 100 keeps on looping back to block 504 to continue receiving inputs from the two temperature sensors 104, 110.

[0055] Upon exceeding the pre-defined time interval, the IDU 100 compares the temperature readings in block 514 where the heat pump is currently active such that there should be some temperature differential. Where temperature T1 and temperature T2 are approximately equal, processing goes to steps to block 510 where the user is notified of a malefaction through the thermostat interface, mobile app, and / or SMS or email messaging. A shutdown of the heat pump is initiated in block 512 since the expected heat exchange is not happening. Alternatively, a system message or diagnostic process kickoff could be initiated at the thermostat 138, diagnostic tool and / or companion app.

[0056] Where the heat pump is exchanging heat effectively with the airstream as determined in block 514, processing continues to block 516 where the mode is determined. Heating mode for the heat pump is where heat is transferred to the airstream using the indoor coil 108. Cooling mode is where heat is removed from the airstream using the indoor coil. If the first and second temperature sensors are installed improperly, that can be detected respectively in block 518 for heating mode and in block 520 for cooling mode.

[0057] The first temperature sensor 104 is upstream of the indoor coil 108 and the second temperature sensor 110 is downstream of the indoor coil 108. Where the indoor coil 108 and temperature sensors 104, 110 are installed according to factory presets for airstream direction, processing from blocks 518 and 520 would go to block 524. In cooling mode, T1 should measure a temperature that is warmer than T2. If that is not the case as determined in block 520, the two temperature sensors are electronically swapped in the control algorithm in block 522 rather than physically reversing them. In heating mode, T1 should measure a temperature that is cooler than T2. If that is not the case as determined in block 518, the two temperature sensors are electronically swapped in the control algorithm in block 522 rather than physically reversing them as the airstream is reversed from factory presets. If the temperatures are as expected for the mode, the indoor coil 524 is installed according to factory presets for airstream direction as determined in block 524.

[0058] Installation problems include reversed intake fans, refrigerant going in the wrong direction, and / or airflow in the reverse direction from factory presets. Where multiple temperature sensors are used, these issues can be diagnosed. The intake fan 106 can be reversed. Misplaced temperature sensors can be identified to substitute the one air coupled with the intake port 102 can be identified and used for control unit 112 to manage operation of the IDU 100.

[0059] Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

[0060] Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above, and / or a combination thereof.

[0061] Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a swim diagram, a data flow diagram, a structure diagram, or a block diagram. Although a depiction may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.

[0062] Furthermore, embodiments may be implemented by hardware, software, scripting languages, firmware, middleware, microcode, hardware description languages, and / or any combination thereof. When implemented in software, firmware, middleware, scripting language, and / or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as a storage medium. A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a script, a class, or any combination of instructions, data structures, and / or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, and / or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0063] For a firmware and / or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory. Memory may be implemented within the processor or external to the processor. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other storage medium and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored.

[0064] Moreover, as disclosed herein, the term “storage medium” may represent one or more memories for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and / or other machine readable mediums for storing information. The term “machine-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage devices, and / or various other storage mediums capable of storing that contain or carry instruction(s) and / or data.

[0065] While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure.

Examples

Embodiment Construction

[0016]The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

[0017]Referring initially to FIG. 1A, a schematic view of a heat pump system 150 according to an embodiment is shown. The heat pump system 150 shows a building or house 103, and a heat pump divided between an indoor unit (IDU) 100 and an outdoor unit (ODU) 118. A thermostat 138 is connected to the IDU 100 to provide a control interface and remote sensors to allow control of the heat pump system 150 according to occupant preferences.

[0018]The heat pump system ...

BACKGROUND

[0001] This disclosure generally relates to a heat pump or air conditioner and, not by way of limitation, sensing the temperatures in the heat pump and applying various algorithms with those temperatures.

[0002] Temperature sensing in a heat pump typically involves using a sensor that is installed at an air intake to measure temperature of incoming return air for the indoor unit (IDU) of the heat pump. The temperature sensor facilitates operational adjustments of components, such as compressor and fan based on the detected temperature. During installation, the sensor can be installed incorrectly causing malfunction of the heat pump and unnecessary rework and possible product returns. For example, the sensor needs to be upstream of the coil and may be moved for proper installation.SUMMARY

[0003] In one embodiment, an indoor unit (IDU) for a heat pump conditioning air of a building is disclosed. The IDU includes an intake port for return air from the building. An indoor coil is air coupled with the intake port. When installed according to factory presets, a first temperature sensor is positioned between the intake port and the indoor coil. A second temperature sensor is positioned at a location opposite to the first temperature sensor and downstream to the indoor coil. A control unit is configured to monitor temperatures from the first temperature sensor and the second temperature sensor to compare temperatures. The control unit uses a control algorithm to identify direction of airflow and confirm proper installation location of the first and second temperature sensor. Depending on the airflow direction, the first and second temperature sensors may be algorithmically switched.

[0004] In an embodiment, an indoor unit for a heat pump is disclosed. The indoor unit includes an indoor coil, first and second temperature sensors, and a control unit. The indoor coil is air coupled with an intake port. The first temperature sensor is designed for positioning between the intake port and the indoor coil. The second temperature sensor is designed for positioning downstream to the indoor coil. The control unit is configured to: monitor temperatures from the first temperature sensor and the second temperature sensor, compare temperatures determined by the first temperature sensor and the second temperature sensor, algorithmically determine which of the first or second temperature sensors is upstream of the indoor coil, and control operation of the heat pump according a reading from the first or second temperature sensors that is determined upstream of the indoor coil.

[0005] In another embodiment, an indoor unit for a heat pump that conditions air of a building is disclosed. The indoor unit includes an intake port for return air, an indoor coil air coupled with the intake port, a first temperature sensor designed for positioning between the intake port and the indoor coil when properly installed, a second temperature sensor designed for positioning at a location opposite to the first temperature sensor and downstream of the indoor coil; and a control unit. The control unit is configured to: monitor temperatures from the first temperature sensor and the second temperature sensor, compare temperatures of the first temperature sensor and the second temperature sensor following a predetermined time interval after initialization of the indoor unit, determine a direction of airflow with respect to the first and second temperature sensors, and determine which of the first and second temperature sensors is installed upstream of the indoor coil to sense the return air based on: the direction of airflow, and comparison of the temperatures.

[0006] In yet another embodiment, a method for automatically configuring an indoor unit of a heat pump that conditions air of a building is disclosed. In one step, temperatures from a first temperature sensor and a second temperature sensor are monitored. The first temperature sensor is upstream of an indoor coil when installed in standard orientation. Temperatures determined by the first temperature sensors and the second temperature sensors are compared to determine a temperature differential. A direction of airflow across the indoor coil is determined based upon the temperature differential and a mode of operation of the heat pump. The temperature of the return air is determined based on: the direction of airflow with respect to the first and second temperature sensors, and temperature differential. A correct temperature of the return air is determined based on a mode of operation of the heat pump.

[0007] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various embodiments, are intended for purposes of illustration only and are not intended to necessarily limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure is described in conjunction with the appended figures:

[0009] FIG. 1A shows indoor and outdoor units with their placement for a building;

[0010] FIG. 1B illustrates a schematic view of an indoor unit (IDU) that is part of a heat pump;

[0011] FIGS. 2A to 2D illustrate various installation configurations of the IDU;

[0012] FIG. 3 illustrates a schematic view of an A-coil of the IDU;

[0013] FIG. 4 illustrates a schematic view of an M-coil of the IDU; and

[0014] FIG. 5 illustrates a temperature sensing method for return air coming inside an IDU unit.

[0015] In the appended figures, similar components and / or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a second alphabetical label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.DETAILED DESCRIPTION

[0016] The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

[0017] Referring initially to FIG. 1A, a schematic view of a heat pump system 150 according to an embodiment is shown. The heat pump system 150 shows a building or house 103, and a heat pump divided between an indoor unit (IDU) 100 and an outdoor unit (ODU) 118. A thermostat 138 is connected to the IDU 100 to provide a control interface and remote sensors to allow control of the heat pump system 150 according to occupant preferences.

[0018] The heat pump system 150 provides heating and cooling for the building 103 with optional humidity control. The outdoor temperature and humidity levels play an important role in determining the operation of the heat pump. When these conditions are not favorable, the heat pump system 150 maintains efficiency and comfort. The ODU 118 includes an ODU fan 105, a heat exchanger coil 106, and a compressor 107. The ODU fan 105 is configured to draw outside ambient air into the ODU 118. The ODU fan 105 ensures a continuous and regulated airflow over the heat exchanger coil 106, thereby facilitating heat exchange.

[0019] The heat exchanger coil 106 is disposed within an airflow path created by the ODU fan 105 in airflow communication with an ODU intake 124 of the ODU 118. In heating mode, the heat exchanger coil 106 functions to absorb heat from the air drawn in by the ODU fan 105, thereby heating the refrigerant passing through the heat exchanger coil 106. The heat exchanger coil 106 is airflow connected to the compressor 107. The compressor 107 is configured to compress the refrigerant, thereby raising the temperature and pressure of the refrigerant. The high-pressure refrigerant is then directed to the IDU 100, specifically to an indoor coil 108.

[0020] The IDU 100 includes the indoor coil 108, a control unit 112, and an exit port 116 to condition building 103. In heating mode for the heat pump system 150, the high-pressure refrigerant from the compressor 107 is directed to the indoor coil 108, where it releases its absorbed heat to the air passing over the indoor coil 108. An indoor fan (not shown) is positioned downstream of the indoor coil 108 in this embodiment. The exit port 116 circulates the heated air throughout building 103, ensuring even distribution of warm air to maintain consistent indoor comfort.

[0021] The control unit 112 is configured to receive data from temperature and humidity sensors in the ODU 118, IDU 100 and any thermostat(s) 138 in the building 103 to control operation of the heat pump system 150 to achieve a desired comfort programmed by occupants. Furthermore, control unit 112 also executes a control algorithm to operate the heat pump system 150, identify malfunctions and reprogram when possible, to fix the malfunctions.

[0022] With regard to FIG. 1B, a schematic view of the IDU 100 that is part of a heat pump to provide heat movement as part of a building is illustrated according to an embodiment of the present disclosure. The IDU 100 includes an intake port 102, a first temperature sensor 104, an intake fan 106, an indoor coil 108, a second temperature sensor 110, and a control unit 112. The indoor coil 108 is configured such that the return air flows downwards through the indoor coil 108 with activation of the intake fan 106. In this embodiment, the intake fan 106 is proximate to the intake port 102. In a different embodiment, the intake fan 106 could be placed proximate to the exit port of the IDU or anywhere in between to move airflow throughout the IDU 100.

[0023] The IDU 100 allows determining temperature of airflow using the first and second temperature sensors 104, 110. The IDU 100 uses two temperature sensors 104, 110, where the first temperature sensor 104 is placed in air communication with an intake port 102 and the second temperature sensor 110 is placed at an opposite location that is downstream of the indoor coil 108. A dual-sensor setup ensures accurate measurement of the temperature of airflow. Additionally, an algorithm can be used with two temperature measurements on each side of indoor coil 108 to confirm airflow direction for the particular installation.

[0024] By positioning the two sensors at alternative sides of the indoor coil 108 with respect to the airflow, the IDU 100 can reliably detect temperature variations, providing a comprehensive understanding of the air temperature conditions impacting performance of the IDU 100. As a result, the IDU 100 becomes “error-proof” for the installers regardless of the orientation of the indoor coil 108 during installation. Generally, indoor coil 108 is designed such that airflow direction and refrigerant direction respectively go in their predetermined directions. Installation of the indoor coil 108 backwards with respect to airflow or the coolant loop reversed may cause the IDU 100 to fail in conventional systems. The IDU 100 installation is labor intensive and improper installation of the temperature sensors 104, 110, indoor coil 108 or other components results in unnecessary rework, faulty operation, and / or product returns.

[0025] The intake port 102 is designed to facilitate entry of return or fresh air into the IDU 100. The intake port 102 serves as an initial point of contact for the airflow before it undergoes any conditioning. The intake port 102 is positioned to intake return air entering the IDU 100 and is at the temperature of the external environment, typically, at indoor temperature for the building. After conditioning by the IDU 100, the airstream is pushed into the building through an exit port 116 as supply air.

[0026] The first temperature sensor 104 is positioned in air communication with the intake port 102 and is responsible for measuring the temperature of the incoming return air. The first temperature sensor 104 is positioned proximate and upstream of the indoor coil 108. The first temperature sensor 104 captures real-time temperature of the incoming return air so that the IDU 100 can monitor and adjust the heating or cooling based on the detected temperature of incoming return air with respect to a set point for the desired air temperature at thermostat 138 and / or other sensor inside the building being conditioned. The first temperature sensor 104 is communicatively connected to the control unit 112 via a wired or wireless connection in various embodiments.

[0027] The intake or blower fan 106 is located upstream of the first temperature sensor 104 and serves to draw the return air through the intake port 102 and into the IDU 100. The intake fan 106 draws of airflow through the indoor coil 108 to have heat exchange for raising or lowering the temperature of the airflow. The intake fan 106 is communicatively connected to control unit 112, which regulates the speed and operation of the intake fan 106 based on the temperature data and desired indoor temperature. For instance, control unit 112 increases the fan speed in response to higher return temperatures to enhance cooling of the airstream. In other embodiments, the intake fan 106 can be downstream of the indoor coil 108 or anywhere in the airstream to pull or push airflow through the IDU 100 from the intake port 102 to exit port 116.

[0028] The indoor coil 108 is positioned downstream of the intake fan 106 and serves as the primary heat exchanger for the IDU unit 100. The indoor coil 108 is air coupled with the intake port 102. The indoor coil 108 is configured as an evaporator coil in a cooling mode or as a condenser coil in a heating mode, depending on desired indoor building temperature. The return air passes over the indoor coil 108 and undergoes temperature modification, either by absorbing or releasing heat. The indoor coil 108 is fluidly connected to a refrigerant circuit, allowing for effective heat transfer to the outdoor unit (not shown). For example, in a cooling scenario, the indoor coil 108 absorbs heat from the airstream to cool the return air before it is distributed throughout the building.

[0029] The second temperature sensor 110 is placed on the opposite side of the indoor coil 108 from the first temperature sensor 104 and measures the temperature of the airstream after temperature modification by passing through the indoor coil 108. The location of the second temperature sensor 110 is downstream to the indoor coil 108. The second temperature sensor 110 is connected to control unit 112 in a similar manner to the first temperature sensor 104 to enable continuous temperature measurement. The second temperature sensor 110 provides feedback to control unit 112 for assessing effectiveness of a heat exchange process. For example, a thermocouple or a resistance temperature detector (RTD) serves as the first and / or second temperature sensors 104,110 to deliver precise temperature readings.

[0030] Control unit 112 controls certain functions of the IDU 100. The control unit 112 receives temperature data from both the first temperature sensor 104 and the second temperature sensor 110, analyzes the information, and adjusts the operation of the intake fan 106 and other components of the IDU 100 and heat pump. The control unit 112 monitors temperatures from the first temperature sensor 104 and the second temperature sensor 110 to compare their temperatures for a control algorithm to determine the direction of airflow with respect to the indoor coil 108. The IDU 100 depicts the direction of airflow using arrows in FIG. 1. The control unit 112 determines temperature of the return air after determining the direction of airflow over the indoor coil 108. When the indoor coil 108 is moving heat from the airstream, readings from the first and second temperature sensors 104, 110 allows algorithmically determining a direction of the airstream regarding the indoor coil 108. The temperature of the return air is determined based on a mode of operation of the heat pump.

[0031] When the heat pump is installed and working properly, a higher temperature is measured by the first temperature sensor 104 than lower temperature of the second temperature sensor 110 when the indoor coil 108 is cooling. For example, if the first temperature sensor 104 measures an incoming return air temperature of 85° F. and the second temperature sensor 110, after air passes over the indoor coil 108, measures a temperature of 75° F., the IDU 100 would consider the higher value of 85° F. as the correct return air temperature such that the IDU 100 is installed correctly. Some conventional systems only have a single temperature sensor and when installed on the wrong side of the indoor coil, the heat pump will not operate correctly. With the two temperature sensors affixed to the indoor coil, the temperature gradient between the two could be the inverse of the designed value indicating that the indoor coil needs to be reversed with respect to the airstream.

[0032] A lower temperature determined by the first temperature sensor 104 with respect to the second temperature sensor 110 is indicative of proper operation when in a heating mode for the heat pump. For example, if the first temperature sensor 104 measures the incoming return air temperature at 60° F. and the second temperature sensor 110, after the air has passed over the indoor coil 108, measures a temperature of 70° F., the IDU 100 will consider the lower value of 60° F. as the correct return air temperature. A positive temperature differential is from the heating effect within the heat pump. Should the indoor coil 108 be installed in a different flow orientation, there would not be a positive temperature differential during heating mode. Algorithmically, the first and second temperature sensors 104, 110 can be switched depending on installed flow direction once a negative temperature differential is detected during a heating mode (or a positive temperature differential in a cooling mode).

[0033] In some embodiments, control unit 112 is configured to detect an unanticipated airflow direction across the indoor coil 108 through unique installations that require different airflow orientation. In those cases where the indoor coil 108 is installed in a reversed orientation with respect to the airstream, the temperature sensors 104, 110 could be installed in an unanticipated configuration with respect to the airstream. For example, the control unit 112 may determine little or no temperature differential from readings from the first temperature sensor 104 and the second temperature sensor 110. Specifically, if the first temperature sensor 104 measures a return air temperature of 70° F. and the second temperature sensor 110, after the air has passed over the indoor coil 108, also measures 70° F., the control unit 112 would interpret this as a potential malfunction in the indoor coil 108. The same or similar temperature readings suggest that the indoor coil 108 is not effectively altering the airstream temperature, which indicates a failure in the heating or the cooling process. Control unit 112 can alert the user or maintenance personnel for further investigation.

[0034] In some embodiments, the control unit 112 is configured to compare the temperatures from the first temperature sensor 104 and the second temperature sensor 110 following a pre-defined time interval after an initiation or activation of the heat pump. This could be performed upon installation or with each cold start after a power interruption in various embodiments. For example, upon starting the IDU 100, the control unit 112 is programmed to wait for 10 minutes after activation of the heat pump before comparing the temperature readings. During this pre-defined time interval, the IDU 100 allows time for the indoor coil 108 to reach its operating temperature, the intake fan 106 to activate, and for the airflow temperature to stabilize. After 10 minutes (or some other predetermined interval), the control unit 112 compares the temperature data from the first temperature sensor 104, which measures the incoming return air, and the second temperature sensor 110, which measures the air temperature after passing over the indoor coil 108. The temperature comparison helps in assessing whether the IDU 100 is functioning correctly by determining if there is an expected temperature differential indicative of proper heating or cooling. In some embodiments, this algorithm is only performed at initial install or periodically thereafter.

[0035] The control unit 112 includes a microprocessor or a programmable logic controller (PLC) programmed with algorithms to optimize the heat pump's performance in conjunction with the ODU 118 and possibly other control units. Additionally, control unit 112 is connected to an external system or user interfaces, allowing for remote monitoring and control such as a thermostat 138 or another controller. Various sensors within the building measuring humidity, temperature, etc. could also report to the control unit 112 to allow algorithms to better maintain desired comfort within the building.

[0036] The IDU 100 further includes a refrigerant leak detector that is communicably coupled with the control unit 112. The control unit 112 is further configured to monitor signals from the leak detector and initiate shutdown of the heat pump upon detection of a leak of refrigerant. For example, if the leak detector identifies a drop in refrigerant pressure or detects the presence of refrigerant in areas where it should not be, the leak detector sends a signal to the control unit 112. The control unit 112 interprets this signal as an indication of a refrigerant leak and promptly activates a shutdown procedure to prevent further damage or inefficiency. This involves turning off the compressor and other components to protect the IDU 100 and ensure safety. Various embodiments could also algorithmically detect blockage or founding of the evaporator, slowly eroding performance of the intake fan or blower, air filter replacement / cleaning reminder, etc.

[0037] Referring next to FIGS. 2A-2D, various installation configurations 200-1, 200-2, 200-3, 200-4 of the IDU 100 are illustrated to show different directions of return air flowing through the indoor coil 108. The technician may install the indoor coil 108 with respect to the airflow differently or even improperly. Proper installation has a temperature sensor measuring the return air prior to temperature conditioning by the indoor coil 108. Depending on the installation, the temperature sensor would be moved in conventional installations for IDUs with a single temperature sensor.

[0038] FIG. 2A depicts a horizontal-left installation configuration 200-1 of the IDU 100 where the return air flows horizontally to the right through the indoor coil 108 when properly installed. In the horizontal-left installation 200-1, the air enters the IDU 100 from the left side of the indoor coil 108 and exits to the right side. The first temperature sensor 104 measures the temperature of the return air, while the second temperature sensor 110 records the temperature of the airflow after it has passed over the indoor coil 108. With two temperature sensors 104, 110 both before and after the indoor coil 108 there will always be temperature sensing of the return air.

[0039] FIG. 2B illustrates a horizontal-right installation configuration 200-2 of the IDU 100 where the return air flows horizontally to the left through the indoor coil 108. Here, the air enters the IDU 100 from the right side with respect to the indoor coil 108 and exits to the left side. Here, the second temperature sensor 110 measures the temperature of the incoming air, while the first temperature sensor 104 records the temperature of the air after it has passed over the indoor coil 108. With the installation having reversed airflow, the control unit 112 uses the second temperature sensor 110 to measure the return air to properly operate the heat pump. Through automatic analysis, the airflow direction can be determined to know if the first or second temperature sensor 104, 110 should measure the return air at the inlet.

[0040] FIG. 2C shows an upflow installation configuration 200-3 of the IDU 100 in which the return air flows vertically upwards through the indoor coil 108. In the upflow installation configuration 200-2, the return air enters from below the indoor coil 108 and exits above. The direction of airflow is depicted by arrows. The first temperature sensor 104 is positioned to detect the temperature of the airflow before passing through the indoor coil 108. The second temperature sensor 110 measures the temperature after the air has been conditioned by the indoor coil 108 before exiting the IDU 100 to condition the building.

[0041] FIG. 2D shows a downflow installation configuration 200-4 of the IDU 100 in which the return air flows vertically downwards through the indoor coil 108. The second temperature sensor 104 is above the indoor coil 108 to sense the return air before any temperature differential is applied to the airstream to condition the building. The control unit 112 adapts control algorithms once airflow direction is determined after installation.

[0042] Regardless of installation configuration 200, the control unit 112 can determine the temperature sensor that is upstream of the indoor coil 108. In the embodiments in FIGS. 2B and 2D, For example, the second temperature sensor 110 measures the return air temperature. The temperature sensor after the indoor coil 108 is the first temperature sensor 104 for measuring the airstream as it returns to the building through exit port 116 once the airstream direction is determined. The control unit 112 automatically determines airflow direction with respect to the coil 108 and temperature sensors to configure the control algorithms accordingly.

[0043] Referring to FIG. 3, illustrates a schematic view of an A-coil 300 that serves as the indoor coil of the IDU 100. Although the indoor coil 108 can come in many different configurations, the A-coil 300 cups the airstream while passing it through to modify the temperature. The A-coil 300 is a type of heat exchanger that is air coupled with the intake port 102, allowing return air to flow through A-coil 300 for conditioning. The A-coil 300 is designed with a distinctive A-shape, which enhances its surface area and efficiency of heat exchange. The return air enters the IDU 100 through the intake port 102 and is directed over the A-coil 300 to lower or raise the temperature of the airstream.

[0044] The first temperature sensor 104 is cupped above an entrance 302 of the A-coil 300. This placement allows first temperature sensor 104 to measure the temperature of the return air as it first contacts the A-coil 300, providing an accurate reading of the return air temperature before any heat exchange occurs. The direction of airflow is depicted by arrows.

[0045] The second temperature sensor 110 is positioned at an apex 304 of the A-coil 300. This location is used for measuring the temperature of the airstream after it has passed through and interacted with the A-coil 300 for heat exchange. By positioning the second temperature sensor 110 at apex 304, the control unit 112 captures the temperature of the air that has been conditioned by the A-coil 300, which can be higher or lower depending on the mode of operation (heating or cooling).

[0046] The direction of return air flow through the A-coil 300 can be configured in various ways. Installers may rotate the A-coil 300 with respect to the airstream, to reverse airflow direction from one side to another or vice versa. For example, the air might flow horizontally from left to right, horizontally from right to left, or vertically from bottom to top with the orientation of the A-coil 300 being rotated appropriately. Regardless of the direction of airflow, the placement of the temperature sensors near the entrance 302 and the apex 304 of the A-coil 300 ensures that accurate temperature measurements are obtained to determine the heat transferred to the airstream. The control unit 112 interprets these measurements and makes necessary adjustments to adjust heat pump operation based on the direction of airflow and the thermal performance of the A-coil 300. This flexibility in airflow direction enhances the adaptability of the heat pump to different installation environments and configurations according to installer preference.

[0047] Referring to FIG. 4, illustrates a schematic view of an M-coil 400 that serves as the indoor coil for the IDU 100 as the heat exchanger component. The M-coil 400 is air coupled with the intake port 102, allowing return air thermal conditioning. The direction of airflow is depicted by arrows in the figures. The design of the M-coil 400 includes an M-shaped configuration to increase surface area available for heat exchange and enhances efficiency of the heat pump.

[0048] The first temperature sensor 104 is positioned at the base 402 of the M-coil 400. This location allows the first temperature sensor 104 to measure the temperature of the return air as it first encounters the M-coil 400. By capturing the temperature at this initial point, the first temperature sensor 104 provides an accurate reading of the incoming air before it undergoes any heating or cooling. For example, if the air flows horizontally from left to right through the M-coil 400, the first temperature sensor 104 would be situated at the leftmost point of the indoor coil where the air initially enters.

[0049] The second temperature sensor 110 is positioned at an apex 404 of the M-coil 400. This sensor measures the temperature of the airflow after it has passed through the M-coil 400. Positioned at the top or apex 404, the second temperature sensor 110 captures the conditioned air temperature, which reflects the thermal effect imparted by the indoor coil. This setup allows for an accurate assessment of the temperature change resulting from the heat exchange process. For instance, if the air flows vertically from bottom to top, the second temperature sensor 110 would be located at the upper end of the indoor coil where the air exits. The airstream direction through the M-coil 400 can vary based on installation requirements. It may flow horizontally from left to right, horizontally from right to left, or vertically from bottom to top. The flexible accommodation of airflow direction ensures that the IDU 100 can be adapted to different installation orientations while maintaining accurate temperature measurement. The control unit 112 can reconfigure which is the first or second temperature sensor according to any orientation of the M-coil 400 with respect to the airflow. The control unit 112 interprets the readings from both temperature sensors to assess system performance and make necessary adjustments, ensuring efficient operation regardless of the direction of airflow through the M-coil 400.

[0050] With reference to FIG. 5, a temperature sensing method 500 for controlling IDU 100 according to an embodiment of the present disclosure is illustrated. Some steps of the temperature sensing method 500 may be performed by the IDU 100 by utilizing processing resources in the control unit 112 and / or ODU 118 or thermostat 138. Some embodiments may use processing resources in the cloud with an Internet connection from the building. Initially, it is presumed that the indoor coil 108 is installed to factory preset airstream direction, and the first temperature sensor 104 is upstream to measure a first temperature T1 and the second temperature sensor 110 is downstream to measure a second temperature T2 on opposite sides of the indoor coil 108. With factory presets, it is presumed that the first temperature sensor 104 is upstream of the indoor coil 108 until the algorithm in this temperature sensing method 500 determines otherwise.

[0051] At block 502, the heat pump operation is initialized. This step involves powering on and / or initializing the heat pump including the IDU 100 and beginning its operation. This could be done upon initial installation or later during ongoing operation after installation. The heat pump then begins to monitor and regulate the indoor air temperature according to the setting from a thermostat 138 or mobile app under the control of a user of the building.

[0052] At block 504, the first temperature sensor 104 receives the first temperature (T1) of the return air entering the air intake of the IDU 100. The first temperature sensor measures the temperature of the airstream before it undergoes any conditioning. For instance, in a commercial building, the first temperature sensor 104 might be located near the air intake 102, ensuring accurate measurement of the return air temperature from the building.

[0053] At block 506, the second temperature sensor 110 receives the second temperature (T2) of the airstream after the heat exchange with the indoor coil 108. Similar to the first temperature sensor 104, the second temperature sensor 110 is placed near the indoor coil 108 to provide an additional temperature reading of the airstream.

[0054] At block 508, the control unit 112 checks if a pre-defined time interval has been exceeded. This interval represents the time for the IDU 100 to condition the airstream after startup before testing for a temperature differential over the indoor coil 108. For example, an IDU may have a pre-defined interval of 15 minutes, after which it assumes the airstream should be sufficiently conditioned to measure and compare temperatures effectively. When the time interval has not been exceeded, the IDU 100 keeps on looping back to block 504 to continue receiving inputs from the two temperature sensors 104, 110.

[0055] Upon exceeding the pre-defined time interval, the IDU 100 compares the temperature readings in block 514 where the heat pump is currently active such that there should be some temperature differential. Where temperature T1 and temperature T2 are approximately equal, processing goes to steps to block 510 where the user is notified of a malefaction through the thermostat interface, mobile app, and / or SMS or email messaging. A shutdown of the heat pump is initiated in block 512 since the expected heat exchange is not happening. Alternatively, a system message or diagnostic process kickoff could be initiated at the thermostat 138, diagnostic tool and / or companion app.

[0056] Where the heat pump is exchanging heat effectively with the airstream as determined in block 514, processing continues to block 516 where the mode is determined. Heating mode for the heat pump is where heat is transferred to the airstream using the indoor coil 108. Cooling mode is where heat is removed from the airstream using the indoor coil. If the first and second temperature sensors are installed improperly, that can be detected respectively in block 518 for heating mode and in block 520 for cooling mode.

[0057] The first temperature sensor 104 is upstream of the indoor coil 108 and the second temperature sensor 110 is downstream of the indoor coil 108. Where the indoor coil 108 and temperature sensors 104, 110 are installed according to factory presets for airstream direction, processing from blocks 518 and 520 would go to block 524. In cooling mode, T1 should measure a temperature that is warmer than T2. If that is not the case as determined in block 520, the two temperature sensors are electronically swapped in the control algorithm in block 522 rather than physically reversing them. In heating mode, T1 should measure a temperature that is cooler than T2. If that is not the case as determined in block 518, the two temperature sensors are electronically swapped in the control algorithm in block 522 rather than physically reversing them as the airstream is reversed from factory presets. If the temperatures are as expected for the mode, the indoor coil 524 is installed according to factory presets for airstream direction as determined in block 524.

[0058] Installation problems include reversed intake fans, refrigerant going in the wrong direction, and / or airflow in the reverse direction from factory presets. Where multiple temperature sensors are used, these issues can be diagnosed. The intake fan 106 can be reversed. Misplaced temperature sensors can be identified to substitute the one air coupled with the intake port 102 can be identified and used for control unit 112 to manage operation of the IDU 100.

[0059] Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

[0060] Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above, and / or a combination thereof.

[0061] Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a swim diagram, a data flow diagram, a structure diagram, or a block diagram. Although a depiction may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.

[0062] Furthermore, embodiments may be implemented by hardware, software, scripting languages, firmware, middleware, microcode, hardware description languages, and / or any combination thereof. When implemented in software, firmware, middleware, scripting language, and / or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as a storage medium. A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a script, a class, or any combination of instructions, data structures, and / or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, and / or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0063] For a firmware and / or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory. Memory may be implemented within the processor or external to the processor. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other storage medium and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored.

[0064] Moreover, as disclosed herein, the term “storage medium” may represent one or more memories for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and / or other machine readable mediums for storing information. The term “machine-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage devices, and / or various other storage mediums capable of storing that contain or carry instruction(s) and / or data.

[0065] While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure.

Examples

Embodiment Construction

[0016]The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

[0017]Referring initially to FIG. 1A, a schematic view of a heat pump system 150 according to an embodiment is shown. The heat pump system 150 shows a building or house 103, and a heat pump divided between an indoor unit (IDU) 100 and an outdoor unit (ODU) 118. A thermostat 138 is connected to the IDU 100 to provide a control interface and remote sensors to allow control of the heat pump system 150 according to occupant preferences.

[0018]The heat pump system ...

Claims

1. An indoor unit for a heat pump, the indoor unit comprising:an indoor coil air coupled with an intake port;a first temperature sensor is designed for positioning between the intake port and the indoor coil;a second temperature sensor is designed for positioning downstream to the indoor coil; anda control unit configured to:monitor temperatures from the first temperature sensor and the second temperature sensor,compare temperatures determined by the first temperature sensor and the second temperature sensor,algorithmically determine which of the first or second temperature sensors is upstream of the indoor coil, andcontrol operation of the heat pump according a reading from the first or second temperature sensors that is determined upstream of the indoor coil.

2. The indoor unit for the heat pump as claimed in claim 1, wherein the indoor coil is an A-coil.

3. The indoor unit for the heat pump as claimed in claim 1, wherein the indoor coil is an M-coil.

4. The indoor unit for the heat pump as claimed in claim 1, wherein the second temperature sensor is upstream to the indoor coil.

5. The indoor unit for the heat pump t as claimed in claim 1, wherein the first or second temperature sensors are affixed to the indoor coil at manufacture.

6. The indoor unit for the heat pump as claimed in claim 1, wherein a status message is generated when the indoor coil is in a cooling mode and the first temperature sensor indicates a lower temperature than the second temperature sensor before algorithmically swapping the first and second temperature sensors.

7. The indoor unit for the heat pump as claimed in claim 1, wherein a status message is generated when the indoor coil is in a heating mode and the first temperature sensor indicates a higher temperature than the second temperature sensor before algorithmically swapping the first and second temperature sensors.

8. The indoor unit for the heat pump as claimed in claim 1, wherein the control unit is configured to generate a status message when the indoor coil is installed opposite to factory presets with respect to airflow as determined from temperature readings from the first and second temperature sensors.

9. The indoor unit for the heat pump as claimed in claim 1, wherein the control unit is configured to determine direction of airflow in the field where:the airflow is upwards through the indoor coil;the airflow is horizontally to right through the indoor coil;the airflow is downwards through the indoor coil; orthe airflow is horizontally to left through the indoor coil.

10. The indoor unit for the heat pump as claimed in claim 1, wherein the control unit is configured to determine direction of airflow in the field and algorithmically swap the first and second temperature sensors when the second temperature sensor is upstream of the indoor coil.

11. An indoor unit for a heat pump that conditions air of a building, the indoor unit comprising:an intake port for return air;an indoor coil air coupled with the intake port;a first temperature sensor designed for positioning between the intake port and the indoor coil when properly installed;a second temperature sensor designed for positioning at a location opposite to the first temperature sensor and downstream of the indoor coil; anda control unit configured to:monitor temperatures from the first temperature sensor and the second temperature sensor,compare temperatures of the first temperature sensor and the second temperature sensor following a predetermined time interval after initialization of the indoor unit,determine a direction of airflow with respect to the first and second temperature sensors, anddetermine which of the first and second temperature sensors is installed upstream of the indoor coil to sense the return air based on:the direction of airflow, andcomparison of the temperatures.

12. The indoor unit for the heat pump that conditions air of the building as claimed in claim 11, wherein a lower temperature for the first temperature sensor than measured by the second temperature sensor is indicative of the heat pump operating in a heating mode unless the first and second temperature sensors are reversed.

13. The indoor unit for the heat pump that conditions air of the building as claimed in claim 11, wherein an A-coil is fluidly coupled with the intake port and the first temperature sensor is positioned at a base of the A-coil, and the second temperature sensor is positioned at a top of the A-coil.

14. The indoor unit for the heat pump that conditions air of the building as claimed in claim 11, wherein an M-coil is fluidly coupled with the intake port and the first temperature sensor is positioned at a base of the M-coil, and the second temperature sensor is positioned at a top of the M-coil.

15. A method for automatically configuring an indoor unit of a heat pump that conditions air of a building, the method comprising:monitoring temperatures from a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is upstream of an indoor coil when installed in standard orientation;comparing temperatures determined by the first temperature sensors and the second temperature sensors to determine a temperature differential;determining a direction of airflow across the indoor coil based upon the temperature differential and a mode of operation of the heat pump; anddetermining temperature of the return air based on:the direction of airflow with respect to the first and second temperature sensors, andtemperature differential,wherein a correct temperature of the return air is determined based on a mode of operation of the heat pump.

16. The method for automatically configuring the indoor unit of the heat pump that conditions air of the building as claimed in claim 15, wherein a higher temperature determined by the first temperature sensor over the second temperature sensor in a heating mode of the heat pump indicates airflow opposite of factory presets for remediation by logically swapping the second temperature sensor for the first temperature sensor.

17. The method for automatically configuring the indoor unit of the heat pump that conditions air of the building as claimed in claim 15, wherein a lower temperature determined by the first temperature sensor over the second temperature sensor in a cooling mode of the heat pump indicates airflow opposite of factory presets for remediation by logically swapping the second temperature sensor for the first temperature sensor.

18. The method for automatically configuring the indoor unit of the heat pump that conditions air of the building as claimed in claim 15, the method further comprises algorithmically swapping the first and second temperature sensors when the second temperature sensor is upstream of the indoor coil.

19. The method for automatically configuring the indoor unit of the heat pump that conditions air of the building as claimed in claim 15, the method further comprises detecting malfunction of the indoor coil upon determining about equal temperatures determined by the first temperature sensor and the second temperature sensor.

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