Auxiliary ambient air refrigeration system for cooling and controlling humidity in an enclosure

Abstract

An auxiliary ambient air refrigeration system for cooling and controlling humidity in an enclosure including a conventional refrigeration unit for providing cool refrigerated air to the enclosure, an auxiliary refrigeration unit for providing cool ambient air to the enclosure, a first sensor unit for sensing air temperature and humidity inside the enclosure, a second sensor unit for sensing ambient air temperature and humidity; and a controller responsive to the sensor units and their indicated dew points of the enclosure air and the ambient air for enabling the auxiliary refrigeration unit to provide cool ambient air to the enclosure when temperature inside the enclosure is above a first predetermined temperature, the ambient temperature is less than the enclosure temperature by a predetermined differential temperature and the dew point of the ambient air is matched to the dew point range of the air in the enclosure.

What is claimed is:   
     
         1 . An auxiliary ambient air refrigeration system for cooling and controlling humidity in an enclosure comprising:
 a conventional refrigeration unit for providing cool refrigerated air to the enclosure;   an auxiliary refrigeration unit for providing cool ambient air to the enclosure;   a first sensor unit for sensing air temperature and humidity inside the enclosure;   a second sensor unit for sensing ambient air temperature and humidity; and   a controller responsive to said sensor units and their indicated dew points of the enclosure air and the ambient air for enabling said auxiliary refrigeration unit to provide cool ambient air to the enclosure when temperature inside the enclosure is above a first predetermined temperature, the ambient temperature is less than the enclosure temperature by a predetermined differential temperature and the dew point of the ambient air is matched to the dew point range of the air in the enclosure.   
     
     
         2 . The auxiliary ambient air refrigeration system of  claim 1  in which said controller is responsive to said sensor units for enabling said conventional refrigeration unit when the enclosure temperature is at a second predetermined temperature higher than said first predetermined temperature. 
     
     
         3 . The auxiliary ambient air refrigeration system of  claim 1  in which said dew point range includes a minimum humidity dew point and the auxiliary refrigeration unit is not enabled if the dew point of the enclosure air is at or below that minimum dew point and if the dew point of the ambient air is below the dew point of the enclosure air. 
     
     
         4 . The auxiliary ambient air refrigeration system of  claim 1  in which said dew point range includes a maximum humidity dew point and the auxiliary refrigeration unit is not enabled if the dew point of the enclosure air is at or above that maximum dew point and if the dew point of the ambient air is above the dew point of the enclosure air. 
     
     
         5 . The auxiliary ambient air refrigeration system of  claim 3  further including a humidifier and said controller is responsive to a humidity below said minimum humidity dew point to enable said humidifier. 
     
     
         6 . The auxiliary ambient air refrigeration system of  claim 1  in which each said sensor unit includes a temperature sensor and a dew point sensor. 
     
     
         7 . The auxiliary ambient air refrigeration system of  claim 1  in which said dew point range includes a minimum humidity dew point and the auxiliary refrigeration unit is not enabled if the dew point of the ambient air is below that minimum dew point. 
     
     
         8 . The auxiliary ambient air refrigeration system of  claim 1  in which said dew point range includes a maximum humidity dew point and the auxiliary refrigeration unit is not enabled if the dew point of the ambient air is above that maximum dew point.