A heat exchanger (100) comprises: a first header tube (1) and two second header tubes (3); a first heat exchange tube (51) in fluid communication with one of the two second header tubes (3) and a second chamber (B) of the first header tube (1); a first runner tube (61) in fluid communication with the one of two second header tubes (3) and a first chamber (A) of the first header tube (1); a second heat exchange tube (52) in fluid communication with the other of the two second header tubes (3) and the first chamber (A) of the first header tube (1); and a second runner tube (62) in fluid communication with the other of the two second header tubes (3) and the second chamber (B) of the first header tube (1). The heat exchanger (100) bends at a first bending portion (71) between the other of the two second header tubes (3) and the first header tube (1), so as to enable the other of the two second header tubes (3) to be higher or lower than the first header tube (1).

Systems and methods for controlling conditions in an enclosed space, such as a data center, or for providing cooling to a device, can include using a Liquid-to-Air Membrane Energy Exchanger (LAMEE) as an evaporative cooler. The LAMEE or exchanger can cool water to the outdoor air wet bulb temperature in a cooling system disposed outside of the enclosed space or device. The reduced-temperature water can be delivered to the enclosed space or device or can cool a coolant that is delivered to the enclosed space or device. The air in the enclosed space, or one or more components in the enclosed space, can be cooled by delivering the reduced-temperature water or coolant to the enclosed space, rather than moving the supply air from the enclosed space to the cooling system. In an example, the cooling system can include one or more cooling coils, upstream or downstream of the LAMEE.

An air delivery system may include a housing, a first liquid-to-air membrane energy exchanger (LAMEE), and a desiccant storage tank. The housing includes a supply air channel and an exhaust air channel. The first LAMEE may be an exhaust LAMEE disposed within an exhaust air channel of the housing. The exhaust LAMEE is configured to receive the outside air during a desiccant regeneration mode in order to regenerate desiccant within the exhaust LAMEE. The desiccant storage tank is in communication with the exhaust LAMEE. The exhaust LAMEE is configured to store regenerated desiccant within the desiccant storage tank. The regenerated desiccant within the desiccant storage tank is configured to be tapped during a normal operation mode.

A humidifying device for transferring water and/or water vapour from waste air of a waste air flow to supply air of a supply air flow is provided. In the compensating chamber of the housing of the humidifying device, at least one spreading means is arranged, which spreads apart the plate stack of the humidifying device and the housing cover closing the housing in the direction of the longitudinal axis.

Systems and methods for providing dehumidification to an enclosed space can include a dehumidification unit in a supply air plenum that receives return air and a regeneration unit in a scavenger air plenum that receives outdoor air. The system can operate in a wet mode and a dry mode, depending on outdoor air conditions and a relative humidity setpoint for the enclosed space. The dehumidification unit and regeneration unit are both operational in the wet mode to dehumidify the return air and regenerate dilute desiccant. In the dry mode, the dehumidification unit and regeneration unit are not needed, and dry outdoor air can be supplied to the enclosed space. A heat recovery system utilizes waste heat from either return air or scavenger air, depending on the operating mode, to heat the outdoor air before it is supplied to the enclosed space or before it is used for regenerating desiccant.

An air conditioner includes an outdoor unit including a compressor for compressing a refrigerant and an outdoor heat exchanger for exchanging heat between the refrigerant and outside air. A ventilation device is connected to the outdoor unit through a liquid refrigerant pipe, a high-pressure refrigerant pipe, and a low-pressure refrigerant pipe. The ventilation device supplies the outside air to an indoor space, and discharges indoor air to the outside. The ventilation device includes a case, a main heat exchanger, a recovery heat exchanger, a refrigerant distributor, and a re-heat heat exchanger. A liquid refrigerant pipe valve is disposed in the liquid refrigerant pipe for controlling an amount of refrigerant.

A heat exchanger for exchanging heat between first and second duct portions of a ventilation system includes first and second heat pipe portions in the first and second duct portions, respectively. Each heat pipe portion can be a heat pipe subassembly including one or more vertical heat pipes fluidly coupled to top and bottom headers, which are respectively connected to the top and bottom headers of the other subassembly to form a refrigerant loop. One or more flow restrictors can block air flow through a respective section of the first or second duct portion. The blocked section can be operatively aligned with a segment of the respective heat pipe portion along which there is a low probability of refrigerant phase change. Each flow restrictor can be an adjustable damper. The damper(s) can be selectively opened and closed as the ventilation system switches between heating and cooling modes.

An air conditioning system including a condenser system and a closed-loop air-to-water system. The condenser system includes a compressor which pressurizes refrigerant and distributes the pressurized refrigerant to at least one condenser coil, which climatizes water; and a fan which exhausts heat from the pressurized refrigerant. The closed-loop air-to-water system includes a climatized liquid tank, which receives climatized water from the at least one condenser coil; and an air handler disposed within a building, the air handler having a climatized liquid coil. The air handler is disposed to receive air from inside the building; transfer thermal energy from the climatized liquid coil to ambient air, creating climatized air; and distribute the climatized air to at least a portion of the building. The climatized water may be distributed to a recycled liquid tank, which may redistribute the climatized water to the climatized liquid tank, forming a closed-loop air-to-water system.

Embodiments of the present disclosure are directed toward a heat exchanger that includes an evaporator coil section disposed at least partially within a first flow structure configured to direct a first flow of air across the evaporator coil section, a condenser coil section fluidly coupled with the evaporator coil section and disposed at least partially within a second flow structure configured to direct a second flow of air across the condenser coil section, and an auxiliary heat exchanger fluidly coupled with the evaporator coil section, where the auxiliary heat exchanger is external to the first flow structure.

A dehumidifying system includes an enclosure having at least one opening disposed at a first end and at least one opening disposed at a second end. A plurality of air paths that extend through the enclosure and are separated from one another by partitions along at least a portion of the enclosure. A dehumidifier evaporator is disposed within the enclosure and configured such that at least one of the air paths is disposed to flow through the dehumidifier evaporator. The dehumidifier evaporator includes a dehumidifying coil and a heat pipe assembly at least partially wrapping around the dehumidification coil.