Variable speed vapor compression systems and methods of controlling humidity with vapor compression systems

Abstract

A variable speed vapor compression system includes a compressor, a first heat exchanger connected to the compressor, an expansion valve connected to the first heat exchanger, a second heat exchanger connecting the expansion valve to the compressor, a fan associated with the second heat exchanger, and a controller operatively connected to one or more of the compressor and the fan. The controller is responsive to instructions to receive a target humidity range for a conditioned space, receive a sensed humidity for the conditioned space, compare the sensed humidity to the target humidity range, and vary speed of one or more of the fan and the compressor based on the comparison of the sensed humidity and the target humidity range. Methods of controlling humidity in conditioned spaces and computer program products are also described.

What is claimed is: 
     
         1 . A variable speed vapor compression system, comprising:
 a compressor;   a first heat exchanger connected to the compressor;   an expansion valve connected to the first heat exchanger;   a second heat exchanger connecting the expansion valve to the compressor;   a fan associated with the second heat exchanger; and   a controller operatively connected to the compressor and the fan, the controller responsive to instructions to:
 receive a target humidity range for a conditioned space; 
 receive a sensed humidity for the conditioned space; 
 compare the sensed humidity to the target humidity range; and 
 vary speed of at least one of the fan and the compressor based on the comparison of the sensed humidity and the target humidity range. 
   
     
     
         2 . The vapor compression system as recited in  claim 1 , wherein the first heat exchanger comprises a condenser, wherein the second heat exchanger comprises an evaporator. 
     
     
         3 . The vapor compression system as recited in  claim 1 , further comprising a variable speed drive operably connected to the compressor. 
     
     
         4 . The vapor compression system as recited in  claim 3 , wherein the instructions cause the variable speed drive to reduce compressor speed when the sensed humidity is within the target humidity range. 
     
     
         5 . The vapor compression system as recited in  claim 3 , wherein the instructions cause the variable speed drive to increase compressor speed when the sensed humidity is outside of the target humidity range. 
     
     
         6 . The vapor compression system as recited in  claim 1 , further comprising a variable speed drive operably connected to the fan. 
     
     
         7 . The vapor compression system as recited in  claim 6 , wherein the instructions cause the variable speed drive to vary fan speed when the sensed humidity is within the target humidity range. 
     
     
         8 . The vapor compression system as recited in  claim 6 , wherein the instructions cause the variable speed drive to vary fan speed when the sensed humidity is outside the target humidity range. 
     
     
         9 . The vapor compression system as recited in  claim 1 , wherein the controller has a comfort mode and an efficiency mode, 
     
     
         10 . The vapor compression system as recited in  claim 9 , wherein the instructions cause the controller to vary speed of at least one of the fan and the compressor by toggling the vapor compression system between the comfort mode and the efficiency mode. 
     
     
         11 . The vapor compression system as recited in  claim 10 , wherein toggling between the comfort mode and the efficiency mode includes automatically selecting between a first efficiency range and a second efficiency range, the first efficiency range having a higher peak efficiency than the second efficiency range. 
     
     
         12 . The vapor compression system as recited in  claim 1 , further comprising:
 a temperature sensor associated with an outlet side of the second heat exchanger and disposed in communication with the controller; and   a pressure sensor associated with an inlet side of the second heat exchanger and disposed in communication with the controller, wherein the instructions cause the controller to vary speed of at least one of the fan and the compressor based on (a) temperature at the outlet end of the second heat exchanger, and (b) pressure at the inlet end of the second heat exchanger.   
     
     
         13 . A method of controlling humidity in a conditioned space, comprising:
 at a variable speed vapor compression system having a compressor, a first heat exchanger connected to the compressor, an expansion valve connected to the first heat exchanger, a second heat exchanger connecting the expansion valve to the compressor, a fan associated with the second heat exchanger, and a controller operatively connected to the compressor and the fan,
 receiving a target humidity range for a conditioned space; 
 receiving a sensed humidity for the conditioned space; 
 comparing the sensed humidity to the target humidity range; and 
 varying speed of at least one of the fan and the compressor based on the comparison of the sensed humidity and the target humidity range. 
   
     
     
         14 . The method as recited in  claim 13 , further comprising reducing compressor speed when the sensed humidity is within the target humidity range. 
     
     
         15 . The method as recited in  claim 13 , further comprising increasing compressor speed when the sensed humidity is outside of the target humidity range. 
     
     
         16 . The method as recited in  claim 13 , further comprising:
 varying fan speed when the sensed humidity is within the target humidity range; and   varying fan speed when the sensed humidity is outside the target humidity range.   
     
     
         17 . The method as recited in  claim 13 , wherein varying speed of at least one of the fan and the compressor includes toggling the vapor compression system between a comfort mode and an efficiency mode. 
     
     
         18 . The method as recited in  claim 13 , further comprising automatically toggling between a first efficiency range and a second efficiency range. 
     
     
         19 . The method as recited in  claim 18 , wherein the first efficiency range has a higher peak efficiency than the second efficiency range. 
     
     
         20 . A computer program product tangibly embodied on a computer readable medium, the computer program product including instructions that, when executed by a processor, cause the processor to perform operations comprising:
 receive a target humidity range for a conditioned space;   receive a sensed humidity for the conditioned space;   compare the sensed humidity to the target humidity range; and   vary speed of at least one of a fan and a compressor based on the comparison of the sensed humidity and the target humidity range.