Humidity control system using desiccant device

Abstract

A humidity control system for an enclosure includes a housing having a process air duct and a regeneration air duct, with return air from the enclosure and/or atmospheric air being supplied to the process air duct and atmospheric air being supplied to the regeneration duct. A desiccant wheel is rotatably mounted in the housing for rotation through the ducts for absorbing moisture in the process air duct and releasing moisture in the regeneration duct. A refrigeration system including a condenser coil in the regeneration duct upstream of the desiccant wheel is connected to a heat pump which includes a heat exchanger and a recirculating fluid loop connected between the condenser coil and the heat exchanger for transferring heat from the recirculating fluid loop to said reactivation airstream.

1 . A humidity control system for an enclosure containing a heating load, a first refrigeration system for cooling the heating load, and a second refrigeration system for removing heat from the first system, said humidity control system including a housing having a process air duct and a regeneration air duct means for supplying return air from the enclosure and/or atmosphere air to the process air duct; means for supplying atmospheric air to the regeneration duct, a desiccant wheel rotatably mounted in said housing for rotation through said ducts whereby it absorbs moisture in the process air duct and releases moisture in the regeneration duct; a third refrigeration system including a condenser coil in said regeneration duct upstream of the desiccant wheel, a compressor connected to said condenser coil, and a heat exchanger connected to said compressor and to said second refrigeration system whereby low grade heat absorbed by the third refrigeration system from said heat exchanger is used by the compressor to generate higher grade heat supplied to the condenser coil to increase the temperature of air supplied to the desiccant wheel in said regeneration duct; and a fourth refrigeration system including a dehumidification coil in said process air stream upstream of said desiccant wheel, at least one compressor connected to said coil and a condenser coil connected to said at least one compressor whereby said at least one compressor in said fourth refrigeration system may be operated in response to humidity levels of the air being supplied in the process air duct to the desiccant wheel to selectively dehumidify such air before it enters the desiccant wheel. 
   
   
       2 . A humidity control system as defined in  claim 1  wherein said at least one compressor comprises a plurality of compressors which may be sequentially activated in response to humidity levels of the air being supplied in the process air duct to the desiccant wheel to selectively dehumidify such air before it enters the desiccant wheel. 
   
   
       3 . A humidity control system for an enclosure including a housing having a process air duct and a regeneration air duct, means for supplying return air from the enclosure and/or atmospheric air to the process air duct; means for supplying atmospheric air to the regeneration duct, a desiccant wheel rotatably mounted in said housing for rotation through said ducts for absorbing moisture in the process air duct and releasing moisture in the regeneration duct; and a refrigeration system including a condenser coil in said regeneration duct upstream of the desiccant wheel and a heat pump connected to said condenser coil, including a heat exchanger and a recirculating fluid loop connected between said condenser coil and heat exchanger for transferring heat from the recirculating fluid loop to said reactivation air stream. 
   
   
       4 . The system in  claim 3  where said fluid loop is decoupled from atmospheric temperature. 
   
   
       5 . The system in  claim 3  where said fluid loop contains a liquid from the group consisting of ground water or glycol loop. 
   
   
       6 . The system in  claim 3  where said fluid loop is a cooling tower loop. 
   
   
       7 . The system in  claim 3  where said fluid loop is a low grade solar heated loop. 
   
   
       8 . The system in  claim 3  where said fluid loop is maintained between 45° F. and 95° F. year round. 
   
   
       9 . The system in  claim 3  where said regeneration air temperature created by the heat pump is between 105° F. and 135° F. 
   
   
       10 . A humidity control system for an enclosure containing a heating load, a first refrigeration system for cooling the heating load, and a second refrigeration system for removing heat from the first system, said humidity control system including a housing having a process air duct and a regeneration air duct, means for supplying return air from the enclosure and/or atmosphere air to the process air duct; means for supplying atmospheric air to the regeneration duct, a desiccant wheel rotatably mounted in said housing for rotation through said ducts whereby it absorbs moisture in the process air duct and releases moisture in the regeneration duct; a third refrigeration system including a condenser coil in said regeneration duct upstream of the desiccant wheel, a compressor connected to said condenser coil, and a heat exchanger connected to said compressor and to said second refrigeration system whereby low grade heat absorbed by the third refrigeration system from said heat exchanger is used by the compressor to generate higher grade heat supplied to the condenser coil to increase the temperature of air supplied to the desiccant wheel in said regeneration duct.