Patent ID: 6138919
Filing Date: 2000-10-31
Classification: F25B

Abstract:
In a heat pump system for a swimming pool or other body of water, said heat pump system being the type which includes a compressor operable responsively to water temperature sensing means, a condenser for receiving water to be heated and returning it in heated state, an evaporator connected with the compressor, and a refrigerant fluid contained in a closed circuit between said compressor, condenser and evaporator, the improvement which comprises:said evaporator containing at least a first section and a second section;each of said sections containing elements in the form of a coil capable of converting said fluid from a liquid to a gaseous state;each of said sections having more than one inlet;each of said sections having a return line connected to said compressor for returning the refrigerant in gaseous state to the compressor;a control valve connected between said first and second sections;a sensor operably connected with a valve control unit;said valve control unit being operably connected with said control valve to open or close said control valve in response to sensed ambient conditions;said valve control unit maintaining said control valve in its closed position in response to a first ambient condition in which a lesser amount of heat is desired from the ambient air, in which event only said first evaporator section is utilized to convert said refrigerant to its gaseous state and deliver it through the first section return line to said compressor;said valve control unit opening said control valve in response to a second ambient condition in which a greater amount of heat is desired from the ambient air, in which event both said first and said second evaporator sections are utilized to convert said refrigerant to its gaseous state, and said refrigerant is delivered through both said first and said second section return lines to said compressor;wherein said second ambient condition is a low temperature condition.