Start-up for refrigerant system with hot gas reheat

Abstract

A refrigerant system has a compressor for compressing and delivering refrigerant to a heat rejecting heat exchanger. Refrigerant from the heat rejecting heat exchanger passes through an expansion device, and then to an evaporator. A reheat circuit includes a reheat valve for selectively tapping refrigerant from a location downstream of the compressor and upstream of the condenser. The reheat refrigerant passes through a reheat heat exchanger, the reheat heat exchanger being positioned to be in a path of air having passed over the evaporator, and delivered into an indoor environment to be conditioned. A control for the refrigerant system is operable to receive inputs from the indoor environment to be conditioned, and to control the several components in the refrigerant system, the control being operable to determine a request for dehumidification provided without any request for significant change in the temperature of the air being delivered into the indoor environment to be conditioned, but said control starting operation of the refrigerant system by enabling cooling mode of operation initially and at least for a short period of time.

1 . A refrigerant system comprising:
 a compressor for compressing and delivering refrigerant to a heat rejecting heat exchanger, refrigerant from the heat rejecting heat exchanger passing through an expansion device, and then to an evaporator;   a reheat circuit including a reheat valve for selectively tapping refrigerant from a location downstream of the compressor and upstream of the heat rejecting heat exchanger, and the tapped refrigerant passing through a reheat heat exchanger, the reheat heat exchanger being positioned to be in a path of air having passed over the evaporator, and to be delivered into an indoor environment to be conditioned; and   a control for the refrigerant system, the control being operable to receive inputs from the indoor environment to be conditioned, and to control the refrigerant system, the control being operable to determine a request for dehumidification provided without any request for significant change in temperature of the air being delivered into the indoor environment to be conditioned, and said control starting operation of the reheat mode of operation by initiating cooling mode of operation at least for a short period of time in response to such a request.   
     
     
         2 . The refrigerant system as set forth in  claim 1 , wherein there is a single refrigerant circuit. 
     
     
         3 . The refrigerant system as set forth in  claim 1 , wherein there are at least two refrigerant circuits incorporated into the refrigerant system. 
     
     
         4 . The refrigerant system as set forth in  claim 3 , wherein at least one of the refrigerant circuits is not provided with a reheat circuit. 
     
     
         5 . The refrigerant system as set forth in  claim 3 , wherein at least one refrigerant flow control device is provided to control the amount of refrigerant passing through the reheat heat exchanger. 
     
     
         6 . The refrigerant system as set forth in  claim 1 , wherein the short period of time is greater than thirty seconds, and less than five minutes. 
     
     
         7 . The refrigerant system as set forth in  claim 3 , wherein the at least two refrigerant circuits have different capacities. 
     
     
         8 . A method of operating a refrigerant system including the steps of:
 receiving a request for dehumidification without any request for significant change in the temperature of the air being delivered into the indoor environment to be conditioned, and starting operation of a refrigerant system by enabling the reheat mode of operation by initiating cooling mode of operation at least for a short period of time in response to such a request.   
     
     
         9 . The method as set forth in  claim 8 , including the step of controlling the amount of refrigerant passing through a reheat heat exchanger. 
     
     
         10 . The method as set forth in  claim 8 , wherein the short period of time is greater than thirty seconds, and less than five minutes.