An air handling unit (1) for cooling down an indoor airflow (A1) including at least one fan (3) circulating the indoor airflow inside the air handling unit (1) and a first and a second cooling subsystems (5, 15) including a refrigeration apparatus (50, 150) comprising an evaporator (500, 1500) and a condenser (504, 1504), a first water circuit (52, 152) connected to the condenser and comprising at least one outside heat exchanger (520, 1520) exposed to outside air (A5, A15), a second water circuit (56, 156) connected to the evaporator and comprising at least one indoor heat exchanger (560, 1560) exposed to the indoor airflow, water connection means (62, 64, 162, 164) for selectively connecting, depending on a temperature of the outside air.

A heating, ventilation, and/or air conditioning (HVAC) system having a return air recycling system that includes a heat exchanger configured to be disposed along a refrigerant circuit of the HVAC system and flow a refrigerant therethrough, an exhaust fan configured to direct return air across the heat exchanger to place the refrigerant in thermal communication with the return air and to exhaust the return air from the HVAC system, and a controller configured to adjust a speed of the exhaust fan, a flow rate of refrigerant through the heat exchanger, or both, based on feedback indicative of a temperature of the return air.

A heat source integrated air conditioner, which includes a freezer, a cooling tower, and a device for heating and is integrated up to heat source supply equipment to be capable of supplying cooling and heating as well as dehumidification, humidification, and ventilation is provided. The heat source integrated air conditioner is formed on an upper side of one frame and installed outside or on a rooftop of a building, thereby reducing time and cost for manufacturing, installation and maintenance, increasing utilization of a space inside a building, reducing heat loss and appliance costs by minimizing piping distance, and creating a pleasant indoor environment, and also enhancing utilization of a space inside the building and maximizing energy saving during operation of cooling/heating.

A refrigeration cycle apparatus includes: a casing; an air handling unit accommodated in the casing and including a first duct and a first outlet, a second duct and a second outlet, a first fan and a second fan; and a refrigerant circuit configured to circulate refrigerant in the refrigerant circuit and including a first heat exchanger and a second heat exchanger.

An example system is configured to control conditions in an enclosed space. The system includes scavenger and process plenums, a liquid-to-air membrane energy exchanger (LAMEE), a first liquid-to-air heat exchanger (LAHX), a second LAHX, and a fluid circuit The scavenger plenum is configured to direct scavenger air from a scavenger inlet to a scavenger outlet. The process plenum is sealed from the scavenger plenum and is configured to direct process air from a process inlet to a process outlet The process inlet receives heated air from the space and the process outlet supplies cooled air to the space. The LAMEE is arranged inside the scavenger plenum. The LAMEE is configured to use the scavenger air to evaporatively cool a first fluid flowing through the LAMEE. The temperature of the first fluid at a LAMEE outlet is lower than the temperature of the first fluid at a LAMEE inlet. The first LAHX is arranged inside the process plenum. The first LAHX is configured to directly and sensibly cool the heated air from the space to a supply air temperature using a second fluid flowing through the first LAHX. The second LAHX is arranged inside the scavenger plenum downstream of the LAMEE. The second LAHX is configured to receive and cool the second fluid heated by the first LAHX using the scavenger air. The fluid circuit transports the first and second fluids among the LAMEE, the first LAHX, and the second LAHX.

An Air Handling Unit for a ventilation system in a building has supply and extract air channels, each with an inlet and an outlet for guiding air to and from a building. Each air channel includes a damper controlling air flow. The air channels are in a heat exchanging relation to each other. The AHU also includes a fan and an Electronic Control Unit. The ECU outputs a defrost cycle initiation signal to defrost the heat recovery arrangement. The ECU outputs a defrost cycle termination signal to end the defrost cycle upon indication of the defrosting being completed. To optimize the defrost cycle time the ECU changes the first or second criterion for defrost cycle termination signal depending on the time for performing the defrost cycle such that the time period of the defrost cycle is prolonged/shortened when the defrost cycle time period is shorter/longer than preferred.

A heat pump cycle includes a compressor, a heat exchanger, a gas-liquid separator, and an outdoor heat exchanger. The heat pump cycle includes a main circuit connecting the compressor, the heat exchanger, the gas-liquid separator, and the outdoor heat exchanger such that refrigerant flows therethrough. The heat pump cycle includes an exhaust-heat recovery heat exchanger, and an exhaust-heat recovery circuit forming a flow path leading to the compressor not through the outdoor heat exchanger but through the exhaust-heat recovery heat exchanger. The heat pump cycle includes an expansion valve that is disposed upstream of the exhaust-heat recovery heat exchanger in the exhaust-heat recovery circuit and expands the refrigerant such that the refrigerant changes from liquid phase to gas phase in the exhaust-heat recovery heat exchanger.

A remote heat transfer device for use with an air handling unit comprises: a vapour-compression circuit, the vapour-compression circuit comprising a first heat exchanger adapted to exchange heat between a refrigerant in the vapour compression circuit and a first heat transfer fluid; and a first outlet arranged to provide the first heat transfer fluid to an air supply passage of the air handling unit, so that the first heat transfer fluid exchanges heat with supply air passing through the air supply passage.

Methods and systems for controlling temperature and humidity within a space in a building. Outdoor air and return air from the space are passed through particular equipment in a particular order. Equipment includes a secondary direct-expansion refrigeration circuit, a recovery wheel, a primary cooling coil or direct-expansion refrigeration circuit, secondary circuit coils, and a dehumidification wheel. Various embodiments include modulating the secondary circuit compressor to adjust reheat capacity at the secondary circuit condenser coil, a geothermal direct-expansion refrigeration circuit, a variable refrigerant flow subsystem, fan coil units, multiple zones, a dedicated outdoor air supply subsystem, an evaporative cooler, supplemental outdoor air, or a combination thereof. In some embodiments, supply air passes first through the recovery wheel, then through the primary cooling coil, then through the dehumidification wheel, and then to the space. Further, in some embodiments, exhaust air passes through the dehumidification wheel, and then through the recovery wheel.

An MVHR system for a building having a roof with at least two pitched slopes facing in different directions. The MVHR system comprises a Heat Recovery Unit (HRU) for exchanging heat between a flow of ambient air and a flow of air from inside the building. The HRU is connected to two ports located on different pitched slopes, and a flow diverter is provided between the HRU and the ports. The flow diverter is switchable so as to reverse the flows of air into and out of the building via the two ports and through the HRU. The system can be combined with photovoltaic solar cells and/or an air source heat pump and/or a ground source heat pump system.