The invention relates to a process air dehumidification system (2) comprising a process air dehumidifier unit (4) comprising a moisture absorbing agent (6), the process air dehumidification system (2) further comprising a moisture absorbing agent regeneration system (8) comprising a closed regeneration air loop (10) arranged to pass through the process air dehumidifier unit (4) and comprising regeneration air flow generating means (12) for generating a regeneration air flow (14) in the closed regeneration air loop (10) and comprising a heat pump (16) comprising a condenser (18) and an evaporator (20) and a heat pump refrigerant (22), where the closed regeneration air loop (10) is arranged to pass through the condenser (18) and the evaporator (20) to exchange heat between regeneration air (24) and heat pump refrigerant (22), where the dehumidification system (2) comprises a complementary regeneration air moisture removal system (26) arranged downstreams of the evaporator (20) and upstreams of the condenser (18) and a regeneration air heat bypass system (28) arranged to exchange heat from inlet regeneration air (30) upstreams of the dehumidifier unit (4) and down-streams of the condenser (18) to outlet regeneration air (32) downstreams of the dehumidifier unit (4) and upstreams of the evaporator (20) and means (34) arranged to activate and deactivate the complementary regeneration air moisture removal system (26) and the regeneration air heat bypass system (28). The invention also relates to a method for dehumidification of process air.

An air conditioning control system includes a casing including paths through which air passes, dampers arranged at an entrance and an exit of each of the paths and operated to open or close the entrance and the exit according to a control signal, a heat and mass exchanger including a hygroscopic material for absorbing moisture and arranged across the paths to be rotated with respect to the casing, a driving unit rotating the heat and mass exchanger, a heat exchange unit having a heat transfer medium flowing inside the heat exchange unit and arranged on at least one of the paths, and a controller opening or closing the entrance and the exit of the paths by applying a control signal to the dampers, and changing a rotation speed of the heat and mass exchanger by applying a control signal to the driving unit, according to operation modes.

An improved HVAC system and method for simultaneously controlling the temperature and humidity of an indoor space while providing high quantities of outdoor air is described herein. The HVAC system of the present invention utilizes a heating source positioned in the supply passageway between an energy recovery wheel and a dehumidification wheel in order to control the temperature and humidity of air supplied to the indoor space while preventing frost build-up on the energy recover wheel. By positioning a heating source between the energy recovery wheel and a dehumidification wheel, the system is able to prevent frost accumulation on the energy recovery wheel during winter operation while also increasing the relative humidity of the supply air.

A dedicated outdoor air system and method that is capable of operating over a broader spectrum of conditions. The HVAC system of the present invention utilizes a heating means positioned within the return air passageway in order to optimize the regeneration of the desiccant wheel and energy recovery device. By positioning a heating means upstream of the regeneration side of the desiccant wheel, the system is capable of providing supply air having low dew points to the enclosed space while still providing improved energy efficiency over conventional HVAC systems.

A dedicated outdoor air system and method that is capable of operating over a broader spectrum of conditions. The HVAC system of the present invention utilizes a heating means positioned within the return air passageway in order to optimize the regeneration of the desiccant wheel and energy recovery device. By positioning a heating means upstream of the regeneration side of the desiccant wheel, the system is capable of providing supply air having low dew points to the enclosed space while still providing improved energy efficiency over conventional HVAC systems.

The invention relates to a process air dehumidification system (2) comprising a process air dehumidifier unit (4) comprising a moisture absorbing agent (6), the process air dehumidification system (2) further comprising a moisture absorbing agent regeneration system (8) comprising a closed regeneration air loop (10) arranged to pass through the process air dehumidifier unit (4) and comprising regeneration air flow generating means (12) for generating a regeneration air flow (14) in the closed regeneration air loop (10) and comprising a heat pump (16) comprising a condenser (18) and an evaporator (20) and a heat pump refrigerant (22), where the closed regeneration air loop (10) is arranged to pass through the condenser (18) and the evaporator (20) to exchange heat between regeneration air (24) and heat pump refrigerant (22), where the dehumidification system (2) comprises a complementary regeneration air moisture removal system (26) arranged downstreams of the evaporator (20) and upstreams of the condenser (18) and a regeneration air heat bypass system (28) arranged to exchange heat from inlet regeneration air (30) upstreams of the dehumidifier unit (4) and downstreams of the condenser (18) to outlet regeneration air (32) downstreams of the dehumidifier unit (4) and upstreams of the evaporator (20) and means (34) arranged to activate and deactivate the complementary regeneration air moisture removal system (26) and the regeneration air heat bypass system (28). The invention also relates to a method for dehumidification of process air.

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.

An air conditioner includes an indoor introduction air path configured to introduce air into an indoor space and an outdoor discharge air path configured to discharge air to an outdoor space, wherein the outdoor discharge air path includes an air path in which heat exchange is performed with the air introduced into the indoor space, and a by-pass path in which heat exchange is not performed with the air introduced into the indoor space, and the air conditioner further includes a controller configured to control the air discharged to the outdoor space so that the air discharged to the outdoor space flows to one of the air paths, in which the heat exchange is performed, and the by-pass path.

Outside air is cooled and dehumidified by a pre-cooler to pass through an adsorption zone of a carbon dioxide adsorbing rotor, producing air having a low carbon dioxide concentration which is cooled by an intercooler. The air that has passed through the intercooler is passed through an adsorption zone of a moisture adsorption rotor and then supplied to a low humidity working chamber. Return air from the low humidity working chamber may be mixed with the air leaving the pre-cooler. A part of the air which passed through the intercooler is branched to pass through a purge zone of the moisture adsorption rotor before being sent to a regeneration zone of the humidity adsorption rotor. Air that passed through the regeneration zone of the humidity adsorption rotor is mixed with outside air and then passed through a regeneration zone of the carbon dioxide adsorption rotor before being exhausted.

An air-conditioning system includes: a dehumidifying unit configured to mix air discharged from an environmental testing chamber with outside air for dehumidification and to discharge dry air; a dry air thermal controlling unit configured to thermally control the dry air discharged from the dehumidifying unit to have a temperature lower than a preset air temperature inside the environmental testing chamber; and a dry air heating unit configured to heat the dry air thermally controlled by the dry air thermal controlling unit up to the preset air temperature and to supply the dry air to the environmental testing chamber. The dehumidifying unit preferably discharges the dry air having a dew point temperature of 30 C. or less.