Ventilation system for buildings, method for controlling a ventilation system, control unit and computer program

Abstract

Ventilation system for buildings with - a central supply air duct (ZuK), - decentralized exhaust air ducts (AbK1, AbK2), each connected to an assigned room (R1, R2) of the building, - an exhaust air duct (FoK) which is connected to the decentralized exhaust air ducts (AbK1, AbK2) for the discharge of exhaust air from the rooms (R1, R2) into the environment of the building, and - a fresh air duct (FrK) which is connected to the central supply air duct (ZuK) for supplying fresh air (FrL) from the environment of the building, wherein - the exhaust air duct (FoK) and the fresh air duct (FrK) are jointly guided through a common heat exchanger (12) for the transfer of heat energy between the exhaust air (FoL) and the fresh air (FrL) supplied, - the exhaust air ducts (AbK1, AbK2) are connected to the supply air duct (ZuK), - at least one air volume control unit (1, 2, 3, 4, 8, 10) is available to vary the proportion of exhaust air from rooms (R1, R2) discharged via the exhaust air ducts (AbK1, AbK2) as supply air (FoL) via the supply air duct (FoK) and the proportion of exhaust air from rooms (R1, R2) discharged via the exhaust air ducts (AbK1, AbK2, ...) as recirculated air (UmL) into the supply air duct (ZuK), and - Air quality sensors for measuring parameters for the air quality of the air in the rooms (R1, R2) of the building connected to the decentralized exhaust air ducts (AbK1, AbK2), as well as - Room temperature sensors are available to measure the room temperature of the respective assigned room (R1, R2) of the building, - a fresh air fan (13) is arranged in the fresh air duct (FrK), and characterized in that - a control unit (14) with the at least one air volume control unit (1, 2, 3, 4, 8, 10) and the fresh air fan (13) as well as with the air quality sensors and room temperature sensors and is configured for primary temperature control with temperature as the primary control variable and air quality as the secondary control variable by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10) and the fresh air fan (13), wherein control with temperature as the primary control variable is achieved by controlling the recirculated air flow with room temperature setpoints and the at least one room temperature measured by the respective room temperature sensor by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10), and only in the event that the air quality measured by the at least one air quality sensor is worse than a predetermined air quality limit value,Control using air quality as a secondary control variable is achieved by increasing the exhaust air ratio and reducing the recirculated air ratio for the room (R1, R2) where the air quality measured by at least one air quality sensor is worse than a predefined air quality limit value.

Description

[0001] The invention relates to a ventilation system for buildings with - a central air supply duct, - decentralized exhaust air ducts, each connected to an assigned room in the building, - an exhaust air duct that is connected to the decentralized exhaust air ducts for the removal of exhaust air from the rooms into the environment of the building, and - a fresh air duct that is connected to the central supply air duct for the supply of fresh air from the environment of the building, where - the exhaust air duct and the fresh air duct are jointly routed through a common heat exchanger for the transfer of heat energy between the exhaust air and the fresh air supplied, - the exhaust air ducts are connected to the supply air duct, - at least one air volume control unit is available to vary the proportion of exhaust air discharged from the rooms via the exhaust air ducts as supply air via the exhaust air duct and the proportion of exhaust air discharged from the rooms via the exhaust air ducts as recirculated air into the supply air duct, and - Air quality sensors for measuring parameters for the air quality of the air in the rooms of the building connected to the decentralized exhaust air ducts, as well as - Room temperature sensors are available to measure the room temperature of the respective assigned room in the building and A fresh air fan is located in the fresh air duct.

[0002] The invention further relates to a method for controlling such a ventilation system, a control unit of such a ventilation system and a computer program for carrying out the above-mentioned method.

[0003] Ventilation systems for buildings, especially for residential buildings such as single-family homes, are primarily designed to ensure adequate air quality in the individual rooms of the building served by the ventilation system. For this purpose, fresh air from the surroundings is drawn into the building, and stale air is extracted from the building as exhaust air.

[0004] The air supplied to a room in a building is called supply air, and the air extracted from a room is called exhaust air. Exhaust air from a room can also be recirculated back into the supply air stream. In this process, the exhaust air can also be mixed with fresh air.

[0005] In single-family homes, fresh air and, if applicable, recirculated air are typically supplied via a common anteroom, such as a hallway or stairwell, so individual supply air ducts to the rooms are not required. Exhaust air, on the other hand, is removed via individual exhaust air ducts connected to the respective room.

[0006] In high-quality ventilation systems, individual rooms can also be equipped with supply air and exhaust air ducts assigned to the room, in order to regulate not only the exhaust air flow via the exhaust air duct, but also the supply air flow.

[0007] EP 3 683 512 A1 describes a control unit for a ventilation system with a main supply air duct and / or an exhaust air duct. Air pressure and air pollution levels are measured to generate an air pressure control variable and an air pollution control variable for the respective room, and thus to perform control using the air pollution control variable as the reference input.

[0008] DE 10 2007 041 041 B4 discloses a system for heating and / or ventilating rooms, comprising an exhaust air duct, a supply air duct, a ventilation duct, and a supply air duct, as well as a counterflow heat exchanger coupled to the exhaust air duct, the ventilation duct, the ventilation duct, and the supply air duct. Excess heat from the exhaust air duct can be temporarily stored in a separate storage tank via the first heat exchanger. A bypass damper and a bypass can direct an air volume flow from the outside air duct through a mixing damper and the bypass to the supply air duct.

[0009] German patent application DE 41 00 674 C2 describes a heating and ventilation system for several rooms served by a single boiler, in which the three main components for heat generation, ventilation (including supply and exhaust air distribution), and heat recovery (heat pump) are integrated within the system. The system retains the conventional hot water heating system and combines it with a ventilation and heat recovery system. The exhaust air from the rooms is fed to a heat pump, which performs the heat recovery function.

[0010] DE 199 00 358 A1 describes a combined heating and ventilation system for buildings in which fresh supply air is heated while stale exhaust air is simultaneously cooled using a heat exchanger and an air-source heat pump. The outside supply air can optionally be pre-tempered before entering the counterflow heat exchanger and from there, via the air-source heat pump with the addition of recirculated air and via PTC thermistor heating coils, directed to the rooms of the consumers.

[0011] DE 10 2010 010 711 A1 discloses a device for ventilating an object with a heat exchanger through which supply air and exhaust air can be directed, and a secondary channel in order to be able to achieve a higher ventilation performance in the short term.

[0012] US 6,698,219 B2 discloses a ventilation and air conditioning system that uses a first variable-volume air system to cool and dehumidify fresh outside air and deliver it through a first duct to a downstream mixing box. The system also uses a second variable-volume air system to further cool and dehumidify the recycled air and deliver it through a second duct to the mixing box, where the fresh and recycled air can mix before being ventilated into a room or office. The system uses a carbon dioxide sensor and a temperature sensor to provide feedback signals to a control system, which in turn regulates fan speeds and damper openings to provide optimal cooling and ventilation and to conserve energy when cooling and ventilation needs are low.

[0013] US Patent 2014 / 0260965 A2 discloses a controlled mechanical ventilation (CMV) system with one or more air ionization devices for increasing operational efficiency and reducing overall costs by lowering the concentration of volatile organic compounds (VOCs) in the recirculated building air. Also disclosed are combinations of heat exchangers that work in conjunction with ionization to further reduce operating costs. Included are various control sequences for a controller that manages air quality using CO2, VOC, and other sensors to maintain air quality at reduced costs.

[0014] US 2012 / 0071082 A1 discloses a method and devices for modular building supply systems and assemblies for a building. A modular system comprises a first assembly with a duct, an inlet pipe, and an outlet pipe, which are coupled via a support in a first positional relationship, wherein the inlet pipe and the outlet pipe are located outside the duct. The modular system comprises a second assembly, which also has a duct, an inlet pipe, and an outlet pipe, which are coupled via a support in a second positional relationship, wherein the inlet pipe and the outlet pipe are also located outside the duct. The first positional relationship of the first assembly and the second positional relationship of the second assembly provide an alignment between the respective ducts, inlet pipes, and outlet pipes to facilitate the coupling of the first and second assemblies.

[0015] Based on this, the object of the present invention is to create an improved ventilation system, a control unit for such a ventilation system, and a method for controlling a ventilation system, which enables energy-optimized control of air quality in relation to heat demand.

[0016] The problem is solved by the ventilation system with the features of claim 1, the method for controlling such a ventilation system with the features of claim 13, the control unit of such a ventilation system with the feature of claim 16, and by the computer program with the features of claim 17. Advantageous embodiments are described in the dependent claims.

[0017] It is proposed for a ventilation system appropriate to the type of product that - a control unit connected to at least one air volume control unit and the fresh air fan, as well as to the air quality sensors and room temperature sensors, and configured for primary temperature control with temperature as the primary control variable and air quality as the secondary control variable by controlling the at least one air volume control unit and the fresh air fan, wherein control with temperature as the primary control variable is achieved by regulating the recirculated airflow with room temperature setpoints and the at least one room temperature measured by the respective room temperature sensor by controlling the at least one air volume control unit, and only if the air quality measured by the at least one air quality sensor is worse than a predetermined air quality limit value, control with air quality as the secondary control variable is achieved bythat an increase in the exhaust air ratio and a reduction in the recirculated air ratio will be implemented for the room in which the air quality measured by at least one air quality sensor is worse than a specified air quality limit value.

[0018] The airflow is regulated by the air volume control unit and the fresh air fan, using temperature as the primary control parameter. Air quality is used as a secondary control parameter. This results in energy-optimized air distribution. Only if the air quality falls below a predefined threshold is the recirculated air volume reduced and the exhaust air volume increased. This approach accepts that heat loss through the removal of heat energy via the exhaust air volume will increase. However, this can be mitigated by limiting the reduction in recirculated air and the increase in exhaust air volume to the room where poor air quality is detected.

[0019] In this way, the ventilation system can be operated in an energy-efficient manner, keeping heating or cooling requirements as low as possible while ensuring adequate air quality in the rooms.

[0020] The exhaust air fan can be located in the exhaust air duct, with the control unit connected to this fan and configured for primary temperature control by controlling the fan. Temperature is the primary control variable, and air quality is the secondary control variable. This exhaust air fan allows the volume of exhaust air to be regulated per unit of time. For example, increasing the fan speed can increase the exhaust air volume and extract more exhaust air from the connected rooms. The volume of exhaust air extracted from each room can be individually controlled using the air volume control unit assigned to that room.

[0021] For the purposes of this invention, a room is understood to mean not only a space within a building separated from other spaces by walls, but also a spatial zone. A spatial zone can be an area within a larger room. However, a spatial zone can also comprise several individual rooms connected to one another by sufficiently large openings.

[0022] The exhaust air fan in the exhaust air duct enables central control of the exhaust air volume.

[0023] At least one air volume control unit can be designed as an air damper.

[0024] At least one of the air volume control units can also be designed as a fan. It is also conceivable that at least one air volume control unit is designed as an air damper and at least one other as a fan, in order to combine the different types of air volume control units.

[0025] When an air volume control unit is designed as a fan, the extraction of exhaust air can be forced through this fan air volume control unit, so that a central exhaust air fan in the exhaust air duct is no longer absolutely necessary.

[0026] The exhaust air ducts of the rooms can each have a branch element to direct a portion of the exhaust air into the supply air duct and a portion as recirculated air into the supply air duct. The air volume control units can then include adjustable exhaust air dampers or controllable fans in the branch element or in the air ducts leading from the branch element to both the supply air duct and the supply air duct. In this way, the branch element allows the proportion of exhaust air extracted as supply air and the proportion of exhaust air reused as recirculated air to be regulated.

[0027] The exhaust air duct can terminate in at least one room exhaust air distributor. A group of air ducts leading from the branch elements to the exhaust air duct can be joined at a common room exhaust air distributor. Such a room exhaust air distributor is not assigned to a single room, but to a group of rooms. The branch elements, on the other hand, are each specifically assigned to a room (or a room zone). Several branch elements are joined by the room exhaust air distributor to direct the exhaust air into the common exhaust air duct.

[0028] Similarly, the supply air duct can terminate in at least one room recirculation distributor. A group of air ducts leading from the branch elements to the supply air duct can be combined in a common room recirculation distributor of the supply air duct. In this way, the airflow from the individual rooms is collected via the branch elements assigned to each room (or room zone) in a common room recirculation distributor and directed into the common recirculation duct.

[0029] The airflow is regulated by a recirculation fan located in a recirculation duct leading from the exhaust air ducts to the supply air duct. The control unit can be connected to and configured with the recirculation fan to regulate its speed, i.e., to adjust the fan's speed as needed.

[0030] Depending on the prevailing air pressure differences between the recirculation duct and the fresh air duct, a backflow from the fresh air duct into the recirculation duct and then into the exhaust ducts can occur, causing air to flow from the fresh air duct, through the recirculation duct, and then through the exhaust ducts into the individual rooms. This can be particularly likely to happen if the recirculation fan is not activated or is switched off, i.e., if the recirculation flow is regulated to a lower level.

[0031] Therefore, it can be advantageous to have a non-return valve in the recirculation duct leading to the supply air duct.

[0032] For the same reasons of preventing backflow in the event of a pressure difference, a non-return valve can also be installed in the fresh air duct.

[0033] The heat exchanger can be, for example, a cross-flow heat exchanger or a rotary heat exchanger that can be controlled by the control unit.

[0034] In a cross-flow heat exchanger, it is advantageous to have a bypass line with a bypass valve. This allows heat exchange to be prevented or reduced as needed. This is equivalent to stopping the rotation of a rotary heat exchanger.

[0035] A rotary heat exchanger offers the advantage of moisture recovery. A disadvantage of rotary heat exchangers can be a slight mixing of exhaust and fresh air. Furthermore, the amount of heat transferred in a rotary heat exchanger can be adjusted by regulating the rotational speed.

[0036] Improved temperature control of the supply air to the rooms can be achieved by connecting a heating and / or cooling coil to the supply air duct to heat or cool the supply air. This allows for rapid and efficient temperature control. The use of a separate heating system can be reduced to a base load or to periods of extreme cold, thus saving expensive fossil fuels. Similarly, efficient room cooling can be achieved with a cooling coil. The heating and / or cooling coil serves to supplement the heat exchange in the heat exchanger. During a desired cooling phase, excess unwanted heat energy contained in the fresh air is transferred to the exhaust air stream via the heat exchanger. Further cooling of the pre-cooled fresh air then occurs using the cooling coil.Conversely, fresh air can be preheated by a warmer exhaust air stream using the heat exchanger and then brought to the desired air temperature using the downstream heating register.

[0037] To balance the amount of supply air to and exhaust air from the rooms, the volume flow of fresh air and exhaust air can be adjusted. This can be achieved by measuring the volume flow in the supply air duct, for example, using a flow velocity sensor. Similarly, the volume flow in the exhaust air duct and the recirculation duct can be measured. Alternatively, the volume flow can be measured only in the fresh air duct and the exhaust air duct and adjusted by the control unit to largely balance the volume flows.

[0038] The at least one air quality sensor can, for example, be designed to measure the carbon dioxide (CO2) concentration. Optionally, an air quality sensor for measuring humidity can also be included.

[0039] Preferably, sensors are used to measure air temperature and air quality, in particular CO2 content and optionally also humidity, as well as the volume flow rate, using a combined air quality sensor unit. Such an air quality sensor or air quality unit can be arranged in an air damper, in the air ducts, or preferably in distributors such as the room exhaust air distributor, the room recirculation air distributor, and / or branch elements.

[0040] A predefined air limit value can, for example, be in the range of 600 ppm to 1,000 ppm, preferably in the range of 800 ppm ± 10%. If the measured air quality for a room exceeds this CO2 limit value, the exhaust air volume for that room is increased and the recirculated air volume is reduced. This, in turn, increases the fresh air volume, and the supply air to all rooms has better quality, as it is less affected by the poor air quality of the affected room via the recirculated air. Over time, this improves the air quality in the room identified as having a high CO2 level, without noticeably affecting the room temperature.

[0041] Optionally, air quality can also be monitored by measuring odors using a VOC sensor, for example, by determining the ammonia concentration. If the fresh air has an unpleasant odor, as can occur during manure spreading in agriculture, the control unit can then reduce the amount of fresh air depending on the detected odor level.

[0042] With such a ventilation system according to claim 1 and optionally a further embodiment according to the dependent claims, temperature-controlled regulation of the proportion of fresh air supplied via the fresh air duct in the supply air and the proportion of recirculated air supplied via the recirculated air duct in the supply air is achieved, so that the amount of heat supplied or removed by a heating and / or cooling coil for room temperature requirements is reduced. Additional heating or cooling of the supply air flow by a heating or cooling coil is required to a minimal extent due to the temperature-dependent control of the recirculated air flow, since the heat or cooling energy contained in the recirculated air flow is reused. Therefore, the ventilation system is primarily temperature-controlled, and only after insufficient air quality is detected in a room is a readjustment carried out using air quality as a secondary control variable.

[0043] The speed of the fresh air recirculation fan can be matched to the speed of the exhaust air fan or to the speeds of the air volume control units designed as fans, so that the amount of fresh air supplied to the building equals the amount of exhaust air extracted from the building. This allows the air pressure within the building to be kept balanced. In this way, the adjustment can also be made to maintain a desired negative or positive pressure within the building.

[0044] The control unit of such a ventilation system can, for example, be configured as an electronic automated measuring and control unit for primary temperature control, with temperature as the primary control variable and air quality as the secondary control variable, by controlling at least one air volume control unit and the fresh air fan. The recirculated airflow is controlled using room temperature setpoints and at least one room temperature measured by the respective room temperature sensor, by controlling at least one air volume control unit. The exhaust air volume is increased and the recirculated air volume is reduced for the room in which the air quality measured by the at least one air quality sensor is lower than a predefined air quality threshold.

[0045] The room temperature sensors do not necessarily have to be located in the room itself. They could also be placed, for example, in the exhaust ducts of the individual rooms and measure the temperature of the exhaust air. This exhaust air temperature is a measure of the room temperature. It is also conceivable that room temperature sensors could be located within each room.

[0046] The invention is explained in more detail below by way of example with reference to the accompanying drawings. These show: Fig. 1 - Block diagram of a first embodiment of the ventilation system; Fig. 2 - Block diagram of a second embodiment of the ventilation system; Fig. 3 - Block diagram of a third embodiment of the ventilation system.

[0047] Fig. Figure 1 shows a block diagram of a ventilation system of a building which has several rooms R1, R2, ... and a corridor through which air, indicated by arrows, can flow via openings into the respective interconnected rooms R1, R2, ... .

[0048] In the illustrated embodiment, the flow of supply air via the corridor into rooms R1, R2, ... is not regulated.

[0049] Supply air (ZuL) is supplied to rooms R1, R2, ... via a supply air duct (ZuK) running through the corridor. The supply air (ZuL) is fed on one side via a fresh air duct (FrK) with fresh air (FrL) and on the other side via a recirculating air duct (UmK) with recirculating air (UmL).

[0050] Exhaust air is extracted from rooms R1, R2, ... via exhaust air ducts AbK1, AbK2, ... which are connected to the rooms. The extracted exhaust air can either be discharged as supply air FoL via a supply air duct FoK or recirculated as recirculated air UmL via the recirculated air duct UmK back to the supply air ZuL.

[0051] To individually control the exhaust and recirculated air volumes for the individual exhaust air ducts AbK1, AbK2, ... and thus for the individual rooms R1, R2, R3, air volume control units 1, 2, 3, 4 are provided for the exhaust air. In the illustrated embodiment, these air volume control units 1, 2, 3, 4 are designed as air dampers and are arranged in the ducts leading to a room exhaust air distributor 5 and a room recirculated air distributor 6, respectively. It is also conceivable that these air volume control units 1, 2, 3, 4 are part of the associated room exhaust air distributor 5 or room recirculated air distributor 6. For this purpose, the air dampers could, for example, be arranged in the inlet openings of the room exhaust air distributor 5 or room recirculated air distributor 6.

[0052] The room exhaust air distributor 5 has an outlet for connection to a common exhaust air duct FoK. In this way, the exhaust air from the individual rooms R1, R2, ... is collected in the room exhaust air distributor 5 and from there forwarded to the exhaust air duct FoK.

[0053] Similarly, the room recirculation distributor 6 has an outlet for the common recirculation duct UmK in order to direct the exhaust air from the individual rooms R1, R2, ... which is led to the room recirculation distributor 6 back into the supply air duct ZuK as recirculated air.

[0054] To change the temperature of the supply air ZuL in the supply air duct ZuK, a heating and / or cooling coil 7 is arranged in the supply air duct ZuK. This brings the supply air ZuL to a desired temperature, for example by heating the mixed recirculated and fresh air stream UmL, FrL or cooling it in warmer seasons.

[0055] Heating element 7 can, for example, be part of a heat pump.

[0056] To regulate the recirculated air volume flow, a recirculating air fan 8 is arranged in the recirculating air duct UmK. Furthermore, a non-return damper 9 may be present in the recirculating air duct UmK to prevent a backflow of recirculated air UmL via the exhaust air ducts AbK1, AbK2, ... into the rooms R1, R2, ... if a corresponding pressure difference exists.

[0057] Likewise, an exhaust air fan 10 is arranged in the exhaust air duct FoK to regulate the exhaust air volume flow of the exhaust air FoL.

[0058] To prevent backflow in the fresh air duct FrK, a non-return valve 11 can be arranged in the fresh air duct FrK.

[0059] Heat exchange between exhaust air FoL and fresh air FrL is achieved by a heat exchanger 12 in which the exhaust air volume flow FoL and fresh air volume flow FrL are combined.

[0060] The illustrated embodiment shows a cross-flow heat exchanger. However, a rotary heat exchanger or similar device can also be used.

[0061] With the aid of the heat exchanger 12, heat still present in the exhaust air (FoL) can be recovered during heating phases when heating is required and transferred to the cooler fresh air (FrL). This preheats the fresh air (FrL) and reduces the energy requirement for the heating coil 7.

[0062] The fresh air volume flow FrL is regulated by a fresh air fan 13.

[0063] A central control unit 14 is provided, which is connected to the air volume control units 1, 2, 3, 4, the recirculating air fan 8, the exhaust air fan 10, the fresh air fan 13, and the heating and cooling coil 7. This makes it possible to regulate the volume flows, heat input, and heat exchange so that rooms R1, R2, ... are supplied with air at the desired temperature.

[0064] A ventilation system is primarily intended to ensure adequate air quality in rooms R1, R2, ...

[0065] This is also achieved in the present ventilation system by providing air quality sensors and room temperature sensors (not shown) for measuring the temperatures of the respective rooms R1, R2, ... and the air quality of the air present in the respective rooms.

[0066] Measuring CO2 levels with a CO2 sensor is particularly suitable for assessing air quality. An air quality limit for CO2 levels can then be set, for example, in the range of 600 to 1,000 ppm, preferably 800 ppm ± 10%. If air quality exceeding this limit is measured for a particular room, the control unit 14 is configured to reduce the recirculated air (UmL) and increase the exhaust air (FoL) ratio. This ensures that the exhaust air of lower quality is primarily discharged as exhaust air (FoL) and is either not recirculated at all or only minimally reintroduced into the supply air. The temperature-controlled settings for the recirculated and exhaust air ratios remain unchanged for the other rooms. This maintains the already sufficiently warmed air quality as recirculated air and keeps the heat input requirement from the heating and cooling coil 7 low. Only the heat generated by the affected room R1, R2, ... then needs to be adjusted.The large temperature difference caused by increasing the exhaust air volume must be compensated for.

[0067] However, through primary temperature control and secondary air quality control using recirculated air, the ventilation system can be operated highly efficiently without unduly impairing the air quality.

[0068] For the occupants of a building, even a slight temperature change is associated with a greater loss of comfort than a deterioration in air quality. The latter is perceived as a secondary disturbance and is regulated by the control unit 14 according to the invention in such a way that a permissible, acceptable air quality is ensured in all rooms R1, R2, ... in that case.

[0069] A heat pump with a heat exchanger, an electric generator, or a combined heat and power plant can be used as a heating and / or cooling coil 7. A communicating heating and cooling coil has the advantage that heating in winter and cooling of the supply air is possible in summer.

[0070] Air quality sensors can also be used to measure humidity, odor (e.g., with a VOC sensor), and nitrogen content (NO₂). X The oxygen content and similar parameters are measured. The control can then be achieved through suitable wiring or programming of the control unit 14, depending on these air quality factors, so that the exhaust air and recirculated air proportions in the individual rooms R1, R2, ... are regulated as required, in order to ensure sufficient air quality while maintaining the target room temperature.

[0071] Fig. Figure 2 shows an alternative embodiment of the ventilation system made of Fig. 1. The air volume control units 1, 2, 3, 4 are designed as fans. The exhaust air from the individual rooms R1, R2, ... is now regulated by the fans and supplied either as exhaust air FoL to the exhaust air duct FoK or as recirculated air UmL to the recirculation air duct UmK. A central exhaust air fan 10 is therefore unnecessary for adjusting the air volume in the exhaust air duct FoK, as is a central recirculation air fan 8.

[0072] While the air volume setting in the exemplary embodiment in Fig. 1 with passive air dampers to the individual rooms R1, R2, ... and active exhaust and recirculation fans 8, 10, are in the embodiment according to Fig. 2. Only the decentralized air volume control units 1, 2, 3, 4 in the form of active fans are necessary. The terms "active" and "passive" refer to the generation of an airflow.

[0073] Furthermore, the design of the ventilation system corresponds to Fig. 1.

[0074] In both embodiments, branch elements 15, 16 are visible, which are connected to another room R1, R2 (or room zone) via a common air duct connection LA1, LA2. These branch elements 15, 16 then divide into two exhaust air ducts, each leading either to the supply air duct FoK or to the recirculation air duct UmK. These ducts can be combined and open into a common room exhaust air distributor 5 or a room recirculation air distributor 6.

[0075] It is also conceivable that the exhaust air duct FoK is connected directly to an assigned room R1, R2, ... via an intermediate room exhaust air distributor 5 and exhaust air ducts FoK. For the recirculated air UmL, air duct openings for the separate recirculated air ducts are then provided in the individual rooms R1, R2, ... In this case, branch elements 15, 16 can be omitted. The air volume control units 1, 2, 3, 4 are then arranged in these decentralized exhaust air and recirculated air ducts FoL, UmL.

[0076] However, a combination of such rooms with separate connections of exhaust air and recirculation air ducts FoK, UmK for the direct discharge of exhaust air as exhaust air FoL and recirculation air UmL and rooms with an initially central air duct connection LA1, LA2 and subsequent branching element 15, 16 is also conceivable.

[0077] Fig. Figure 3 shows a third embodiment of the ventilation system, which in turn is based on the first embodiment of the ventilation system made of Fig. 1. In contrast, the air volume control unit in the form of the recirculation fan 8 is no longer present. To regulate the recirculation flow UmL, an adjustable recirculation air flap 18 is provided instead of the non-return flap 9. This adjustable recirculation air flap 18 is controlled by the control unit 14.

[0078] Likewise, the fresh air fan 13 from the first embodiment is no longer present, and the non-return flap 11 has been replaced by an adjustable fresh air damper 19. This damper is also controlled by the control unit 14 in order to regulate the volume flow of the fresh air FrL.

[0079] The volume flow in the recirculating air duct UmK and the fresh air duct FrK is controlled by a supply air fan 17 using the control unit 14. This supply air fan 17 is located in the supply air duct ZuK behind the heating coil 7 in order to draw in the fresh air FrL and recirculated air UmL and supply it as supply air ZuL via the corridor to rooms R1, R2, ...

[0080] The amount of recirculated air (UmL) and fresh air (FrL) is adjusted by controlling the recirculated air damper 18 and the fresh air air damper 19. The proportion of exhaust air (FoL) and recirculated air (UmL) is controlled by controlling the exhaust air fan 10 and the recirculated air damper 18.

[0081] This embodiment is further combined with the variant from Fig. 2. This can be combined by designing the air volume control units 1, 3, which are designed as air flaps, as fans for the exhaust air extracted as exhaust air FoL. Then the common exhaust air fan 10 can be omitted.

[0082] Optionally, the air flaps 2 and 4 intended for recirculation can also be designed as active fans. This ensures sufficient overpressure in the recirculation duct UmK compared to the air pressure in the fresh air duct FrK.

[0083] In all different embodiments, the volume flow of the exhaust air FoL and / or fresh air FrL and / or recirculated air UmL can be temperature-controlled to meet the greatest air demand, so that the air volume control unit 1, 2, 3, 4, which is open the widest or generates / permits the largest volume flow, specifies the required volume flow.

Claims

[1] Ventilation system for buildings with - a central supply air duct (ZuK), - decentralized exhaust air ducts (AbK1, AbK2), each connected to an assigned room (R1, R2) of the building, - an exhaust air duct (FoK) which is connected to the decentralized exhaust air ducts (AbK1, AbK2) for the discharge of exhaust air from the rooms (R1, R2) into the environment of the building, and - a fresh air duct (FrK) which is connected to the central supply air duct (ZuK) for supplying fresh air (FrL) from the environment of the building, wherein - the exhaust air duct (FoK) and the fresh air duct (FrK) are jointly guided through a common heat exchanger (12) for the transfer of heat energy between the exhaust air (FoL) and the fresh air (FrL) supplied, - the exhaust air ducts (AbK1, AbK2) are connected to the supply air duct (ZuK), - at least one air volume control unit (1, 2, 3, 4, 8, 10) is available to vary the proportion of exhaust air from rooms (R1, R2) discharged via the exhaust air ducts (AbK1, AbK2) as supply air (FoL) via the supply air duct (FoK) and the proportion of exhaust air from rooms (R1, R2) discharged via the exhaust air ducts (AbK1, AbK2, ...) as recirculated air (UmL) into the supply air duct (ZuK), and - Air quality sensors for measuring parameters for the air quality of the air in the rooms (R1, R2) of the building connected to the decentralized exhaust air ducts (AbK1, AbK2), as well as - Room temperature sensors are available to measure the room temperature of the respective assigned room (R1, R2) of the building, - a fresh air fan (13) is arranged in the fresh air duct (FrK), and characterized by , that - a control unit (14) with the at least one air volume control unit (1, 2, 3, 4, 8, 10) and the fresh air fan (13) as well as with the air quality sensors and room temperature sensors and is configured for primary temperature control with temperature as the primary control variable and air quality as the secondary control variable by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10) and the fresh air fan (13), wherein control with temperature as the primary control variable is achieved by controlling the recirculated air flow with room temperature setpoints and the at least one room temperature measured by the respective room temperature sensor by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10), and only in the event that the air quality measured by the at least one air quality sensor is worse than a predetermined air quality limit value,Control using air quality as a secondary control variable is achieved by increasing the exhaust air ratio and reducing the recirculated air ratio for the room (R1, R2) where the air quality measured by at least one air quality sensor is worse than a predefined air quality limit value. [2] Ventilation system according to claim 1, characterized by , that an exhaust air fan (10) is arranged in the exhaust air duct (FoK) and the control unit (14) is further connected to the exhaust air fan (10) and is set up for primary temperature control with the temperature as the primary control variable and the air quality as the secondary control variable by controlling the exhaust air fan (10). [3] Ventilation system according to claim 1 or 2, characterized by , that at least one air volume control unit (1, 2, 3, 4, 8, 10) is designed as an air damper. [4] Ventilation system according to one of claims 1 to 3, characterized by, that at least one air volume control unit (1, 2, 3, 4, 8, 10) is designed as a fan. [5] Ventilation system according to one of claims 1 to 4, characterized by , that the exhaust air ducts (AbK1, AbK2) of the rooms (R1, R2) each have a branch element (15, 16) for directing a portion of the exhaust air into the supply air duct (FoK) and a portion of the exhaust air as recirculated air (UmL) into the supply air duct (ZuK) and the air volume control units (1, 2, 3, 4, 8, 10) include adjustable exhaust air dampers or controllable fans in the branch element (15, 16) or in the air ducts leading from the branch element (15, 16) into the supply air duct (FoK) and the supply air duct (ZuK). [6] Ventilation system according to claim 5, characterized by, that the exhaust air duct (FoK) leads into at least one room exhaust air distributor (5) and a group of the air ducts leading from the branch elements (15, 16) to the exhaust air duct (FoK) are combined in a common room exhaust air distributor (5) of the exhaust air duct (FoK). [7] Ventilation system according to claim 5 or 6, characterized by , that the supply air duct (ZuK) leads into at least one room recirculation distributor (6) and a group of the air ducts leading from the branch elements (15, 16) to the supply air duct (ZuK) are combined in a common room recirculation distributor (6) of the supply air duct (ZuK). [8] Ventilation system according to one of the preceding claims, characterized by , that a recirculation fan (8) is arranged in a recirculation duct (UmK) leading from the exhaust air ducts (AbK1, AbK2) to the supply air duct (ZuK), wherein the control unit (14) for controlling the recirculation fan (8) is connected to the recirculation fan (8). [9] Ventilation system according to one of the preceding claims, characterized by a non-return valve (11) in the fresh air duct (FrK) and / or a non-return valve (9) in the recirculation duct (UmK) leading from the exhaust air ducts (AbK1, AbK2) to the supply air duct (ZuK). [10] Ventilation system according to one of the preceding claims, characterized by , that the heat exchanger (12) is a cross-flow heat exchanger or a rotary heat exchanger controllable by the control unit (14). [11] Ventilation system according to one of the preceding claims, characterized by , that a heating and / or cooling register (7) is connected to the supply air duct (ZuK) for heating or cooling the supply air (ZuL). [12] Ventilation system according to claim 11, characterized by , that the control unit (14) is connected to the heating and / or cooling register (7) and is designed to control the temperature of the supply air (ZuL) in the supply air duct (ZuK) with the heating and / or cooling register (7) using a setpoint supply air temperature. [13] Method for controlling a ventilation system according to one of the preceding claims, characterized byPrimary temperature control with temperature as the primary control variable and air quality as the secondary control variable by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10) and the fresh air fan (13), wherein control with temperature as the primary control variable is achieved by regulating the recirculated air flow with room temperature setpoints and the at least one room temperature measured by the respective room temperature sensor by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10), and only if the air quality measured by the at least one air quality sensor is worse than a predetermined air quality limit value, control with air quality as the secondary control variable is achieved by increasing the exhaust air proportion and reducing the recirculated air proportion for the room (R1, R2).where the air quality measured by at least one air quality sensor is worse than a specified air quality limit. [14] Method according to claim 13, characterized by temperature-controlled regulation of the proportion of fresh air (FrL) supplied through the fresh air duct (FrK) in the supply air (ZuL) and the proportion of recirculated air (UmL) supplied through the recirculation duct (UmK) in the supply air (ZuL), so that the amount of heat supplied or removed by the heating and / or cooling register (7) for the room temperature requirement is reduced. [15] Method according to claim 13 or 14, characterized by , that the speed of the fresh air fan (13) is coordinated with the speed of the exhaust air fan (10) or with the speeds of the air volume control units (1, 2, 3, 4, 8, 10) designed as fans, so that the amount of fresh air (FrL) supplied into the building corresponds to the amount of exhaust air (FoL) extracted from the building. [16] Control unit (14) of a ventilation system according to one of claims 1 to 12, characterized by, that the control unit (14) is configured for primary temperature control with temperature as the primary control variable and air quality as the secondary control variable by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10) and the fresh air fan (13), wherein control with temperature as the primary control variable is achieved by controlling the recirculated air flow with room temperature setpoints and the at least one room temperature measured by the respective room temperature sensor by controlling the at least one air volume control unit (1, 2, 3, 4, 8, 10), and only if the air quality measured by the at least one air quality sensor is worse than a predetermined air quality limit value, control with air quality as the secondary control variable is achieved by increasing the exhaust air proportion and reducing the recirculated air proportion for the room (R1, R2),where the air quality measured by at least one air quality sensor is worse than a specified air quality limit. [17] Computer program comprising instructions which, when the program is executed by a computer, cause it to execute the method comprising the steps according to any one of claims 13 to 15.

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