Patent ID: 7171817
Filing Date: 2007-02-06
Classification: F25B

Abstract:
1. A method for maintaining the production of heat on an indoor heat exchanger connected to an outdoor heat exchanger that uses cool vapor refrigerant to produce heat for the indoor heat exchanger while selectively defrosting the outdoor heat exchanger, said method comprising the following steps; a. selecting an outdoor heat exchanger that includes plurality of coil subsystems each being connected at two ends to a main liquid refrigerant line that connects to the indoor heat exchanger and at a third end to a secondary transfer line that connects to said indoor heat exchanger; b. monitoring the temperature or the accumulation of frost on each said coil subsystem on said outdoor heat exchanger; and, c. selectively stopping the flow of said cool vapor refrigerant from said secondary transfer line through at least one said coil subsystem when a low temperature is detected or accumulation of frost is detected thereon while maintaining the flow of cool vapor refrigerant from said secondary transfer line in the remaining coil subsystems to produce heat for said indoor heat exchanger.