An air treatment apparatus includes: a total heat exchanger; a heat supply device having a heater and a cooler; an upper damper; and a complex dehumidification device having a first stationary desiccant and a second stationary desiccant. The upper damper allows return air (RA) to flow into one of the first stationary desiccant and the second stationary desiccant, and allows outdoor air (OA) to flow into the other one of the first stationary desiccant and the second stationary desiccant. The upper damper switches between a return air path and an outdoor air path so that the return air (RA) and the outdoor air (OA) pass through different ones of the first stationary desiccant and the second stationary desiccant.

A metering device is fluidly coupled to the condenser coil. A distributor is fluidly coupled to the metering device. An evaporator coil is fluidly coupled to the distributor via a plurality of evaporator circuit lines. A re-heat coil is disposed adjacent to the evaporator coil. The re-heat coil includes a first fluid connection to the metering device via a re-heat return line and a second re-heat feed line. The re-heat coil includes a second fluid connection to the condenser coil via a connecting line and a condenser intake line. A first check valve is disposed between the connecting line and the condenser intake line. A second check valve is disposed between the re-heat return line and the second re-heat feed line.

A refrigerant sub-system includes a compressor, a condenser, an expansion valve, an evaporator, and a refrigerant-air heat exchanger. The compressor receives and compresses refrigerant. The condenser condenses the refrigerant and transfers heat from the refrigerant to a first fluid. The expansion valve expands the refrigerant. The evaporator vaporizes the refrigerant at the first pressure and transfers heat from a second fluid to the refrigerant. The refrigerant-air heat exchanger has a first operating mode and a second operating mode. In the first operating mode, the condenser is adapted to condense a first portion of the refrigerant from a vapor to a liquid, and the refrigerant-air heat exchanger is adapted to condense a second portion of the refrigerant from a vapor to a liquid and transfer heat from the second portion of the refrigerant to air.

A heating, ventilation, and air conditioning (HVAC) system includes a heat pump having a housing. The HVAC system also includes an energy recovery ventilator (ERV) or heat recover ventilator (HRV) integrated with the heat pump such that an access panel to the ERV or HRV faces outwardly from the housing of the heat pump, and such that the access panel is accessible at an outer boundary of the housing.

In an air conditioning system, a cooling tower cools cooling water. A chiller generates cold water using the cooling water cooled by the cooling tower. A cooling water circulation passage circulates cooling water between the cooling tower and chiller. A first heat exchanger exchanges heat between air and the cold water generated by the chiller. A cold water circulation passage circulates the cold water between the chiller and first heat exchanger. A second heat exchanger exchanges heat between a portion of the cooling water cooled by the cooling tower and air heat-exchanged with the cold water. A cooling water branch passage, branching from the cooling water circulation passage, introduces to the second heat exchanger the portion of the cooling water introduced to the chiller from the cooling tower, and introduces to the cooling water circulation passage the portion of the cooling water heat-exchanged with air by the second heat exchanger.

Disclosed herein are systems and processes to thermally regenerate and re-concentrate a liquid desiccant (absorbent) with an electrically driven heat pump. The regeneration and re-concentration may be performed in a cost and energy efficient manner.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and a valve coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine that the outdoor heat pump unit is in operation during an air conditioning cycle. The controllers are further operable to determine an outdoor temperature and compare the outdoor temperature to a predetermined temperature. The controllers are further operable to initiate a closure of the valve coupled to the refrigerant line and initiate operation of the compressor at an end of the air conditioning cycle to pump down a refrigerant to the outdoor coil in response to comparing the outdoor temperature to the predetermined temperature.

A metering device is fluidly coupled to the condenser coil. A distributor is fluidly coupled to the metering device. An evaporator coil is fluidly coupled to the distributor via a plurality of evaporator circuit lines. Are-heat coil is disposed adjacent to the evaporator coil. The re-heat coil includes a first fluid connection to the metering device via a re-heat return line and a second re-heat feed line. The re-heat coil includes a second fluid connection to the condenser coil via a connecting line and a condenser intake line. A first check valve is disposed between the connecting line and the condenser intake line. A second check valve is disposed between the re-heat return line and the second re-heat feed line.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and an EEV coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine an occurrence of a first event, initiate a closure of the EEV, initiate operation of the compressor at a completion of the air conditioning cycle to pump down a refrigerant to the outdoor coil, and cease operation of the compressor when a low-pressure switch is tripped.

A metering device is fluidly coupled to the condenser coil. A distributor is fluidly coupled to the metering device. An evaporator coil is fluidly coupled to the distributor via a plurality of evaporator circuit lines. A re-heat coil is disposed adjacent to the evaporator coil. The re-heat coil includes a first fluid connection to the metering device via a re-heat return line and a second re-heat feed line. The re-heat coil includes a second fluid connection to the condenser coil via a connecting line and a condenser intake line. A first check valve is disposed between the connecting line and the condenser intake line. A second check valve is disposed between the re-heat return line and the second re-heat feed line.