Double DX Hydronic System

Abstract

A double DX hydronic heating/cooling system includes a primary DX system for maintaining a primary interior fluid loop at a desired temperature range. Secondary DX sub-systems are operatively coupled to the primary interior fluid loop and are operable in either a heating mode or a cooling mode to provide independent control of interior air temperature in different spaces. Each sub-system includes a dedicated water pump to minimize power requirements for the system.

1 . A direct exchange geothermal heating/cooling system, comprising:
 a primary heat exchange sub-system including a sub-surface primary heat exchanger, a compressor box operatively coupled to the primary heat exchanger, a primary interior heat exchanger operatively coupled to the primary heat exchanger, and an interior fluid loop operatively coupled to the primary interior heat exchanger;   first and second transfer heat exchangers operatively coupled to the interior fluid loop;   a first secondary heat exchange sub-system operatively coupled to the first transfer heat exchanger and including a first secondary compressor box and a first secondary interior heat exchanger; and   a second secondary heat exchange sub-system operatively coupled to the second transfer heat exchanger and including a second secondary compressor box and a second secondary interior heat exchanger.   
     
     
         2 . The system of  claim 1 , in which the primary heat exchange sub-system is operated to maintain fluid in the interior fluid loop within a temperature range of approximately 50 degrees F. to approximately 80 degrees F. 
     
     
         3 . The system of  claim 2 , in which the system is operable in a cooling mode, and in which the temperature range is maintained in the cooling mode. 
     
     
         4 . The system of  claim 2  in which the system is operable in a heating mode, and in which the temperature range is maintained in the heating mode. 
     
     
         5 . The system of  claim 1 , in which the primary heat exchange sub-system is operated to maintain fluid in the interior fluid loop within a temperature range of approximately 50 degrees F. to approximately 65 degrees F. 
     
     
         6 . The system of  claim 5 , in which the system is operable in a cooling mode, and in which the temperature range is maintained in the cooling mode. 
     
     
         7 . The system of  claim 1 , in which the primary heat exchange sub-system is operated to maintain fluid in the interior fluid loop within a temperature range of approximately 38 degrees F. to approximately 68 degrees F. 
     
     
         8 . The system of  claim 7 , in which the system is operable in a heating mode, and in which the temperature range is maintained in the heating mode. 
     
     
         9 . The system of  claim 1 , in which the interior fluid loop includes:
 a primary supply line having a first end fluidly communicating with the primary interior heat exchanger and a second end;   a first distributed supply line having a first end fluidly communicating with the primary supply line second end and a second end fluidly communicating with the first transfer heat exchanger;   a second distributed supply line having a first end fluidly communicating with the primary supply line second end and a second end fluidly communicating with the second transfer heat exchanger;   a first distributed return line having a first end fluidly communicating with the first transfer heat exchanger and a second end;   a second distributed return line having a first end fluidly communicating with the second transfer heat exchanger and a second end; and   a primary return line having a first end fluidly communicating with the first and second distributed return line second ends and a second end fluidly communicating with the primary interior heat exchanger.   
     
     
         10 . The system of  claim 9 , further comprising a first pump disposed in the first distributed return line and a second pump disposed in the second distributed return line. 
     
     
         11 . The system of  claim 10 , further comprising a pump controller configured to selectively operate the first pump only when the first secondary heat exchange sub-system is operative and the second pump only when the second secondary heat exchange sub-system is operative.