Air conditioning system with temperature responsive controls

Claim 1

In an air conditioning system including a compressor, condenser, and evaporator wherein the compressor provides a heat laden refrigerant under relatively high pressure to the condenser which rejects heat from and condenses the refrigerant so that lower heat level liquid refrigerant can be supplied to the evaporator, there being a refrigerant flow control valve between the condenser outlet and evaporator inlet to reduce the pressure of the refrigerant fed to the evaporator, the improvement comprising a refrigerant bypass line for passing the heat laden highpressure refrigerant from the compressor output into the reduced-pressure lower heat level refrigerant between said flow control and the inlet to said compressor, a bypass valve in said bypass line for controlling the flow of said heat laden rerigerant in said bypass line, said valve including a bimetallic element and an electrical heating element for flexing said bimetallic element, a temperature responsive probe arranged outside of the direct flow of air across the evaporator and responsive to the room temperature of the space to be cooled, means for coupling an electrical signal from said temperature responsive probe to said electrical heating element for controlling the condition of said valve to vary the temperature of the discharge air flowing across the evaporator to maintain said room temperature at a preselected level by varying the thermal capacity of the air conditioner, a second temperature responsive probe responsive to the temperature of the outside air, and means responsive to said second temperature responsive probe for varying the magnitude of the voltage applied to said heating element by said first-named temperature responsive probe.