Abstract: A refrigeration expansion valve meters the flow of refrigerant therethrough through a flexible orifice that varies in cross-sectional area as a function of the pressure differential across the valve.

Abstract: Apparatus and a method for operating a series compression refrigeration circuit with supplemental heating means are disclosed. The supplemental heat source is arranged to supply heat energy to the refrigerant being supplied to the high stage compressor suction line. A quench conduit is provided for effectively regulating the temperature of the refrigerant entering the high stage compressor. This arrangement allows for the simultaneous heating of the refrigerant for supplying supplemental heat energy and for continued utilization of the outdoor heat exchanger for absorbing heat energy from the outdoor ambient air for transfer to a space to be conditioned.

Abstract: Apparatus and method for operating a series compression refrigeration system are disclosed. A by-pass for circuiting refrigerant around one compressor when the compressor is not operating is provided. Additionally, a quench conduit conducts liquid refrigerant from a common line to provide a liquid refrigerant quench of the gaseous refrigerant between compressors. A control device is provided for regulating the flow of liquid refrigerant through the quench conduit.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor is conducted into a heat exchanger mounted within an accumulator for supplying heat to vaporize liquid refrigerant received from the evaporator. After the gas passes through the heat exchanger it is conducted to the condenser where it is condensed to a liquid and then routed to the evaporator. In the evaporator or frost accumulating coil the liquid refrigerant is subcooled, supplying heat to melt the ice formed on the evaporator surfaces and the liquid is thereafter conducted to the accumulator where the heat supplied from the heat exchanger acts to vaporize the fluid. The vaporized refrigerant is then recycled to the compressor to complete the system.

Abstract: Apparatus and method for operating a series compression refrigeration system are disclosed. A by-pass for circuiting refrigerant around one compressor when the compressor is not operating is provided. Additionally, a quench conduit conducts liquid refrigerant from a common line to provide a liquid refrigerant quench of the gaseous refrigerant between compressors. A control device is provided for regulating the flow of liquid refrigerant through the quench conduit.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor outlet is conducted directly into the heat exchanger to be defrosted, by-passing the condenser and thermal expansion valve to effect removal of the frost and ice accumulation on the heat exchanger surface. A portion of the hot compressor discharge gas is conducted directly into an accumulator with the liquid refrigerant received from the heat exchanger to be defrosted, the liquid refrigerant resulting from the gaseous refrigerant being condensed in the heat exchanger as the ice is melted. The refrigerant condensed to a liquid during defrost is vaporized in the accumulator thereby providing a supply of gaseous refrigerant to the compressor suction line, said gaseous refrigerant being a combination of the non-condensed discharge gas conducted to the accumulator and the liquid refrigerant vaporized in the accumulator.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor outlet is conducted directly into the heat exchanger to be defrosted, by-passing the condenser and thermal expansion valve to effect removal of the frost and ice accumulation on the heat exchanger surface. A portion of the hot compressor discharge gas is conducted directly into an accumulator with the liquid refrigerant received from the heat exchanger to be defrosted, the liquid refrigerant resulting from the gaseous refrigerant being condensed in the heat exchanger as the ice is melted. The refrigerant condensed to a liquid during defrost is vaporized in the accumulator thereby providing a supply of gaseous refrigerant to the compressor suction line, said gaseous refrigerant being a combination of the non-condensed discharge gas conducted to the accumulator and the liquid refrigerant vaporized in the accumlator.

Abstract: Apparatus and method for operating a series compression refrigeration system are disclosed. A by-pass for circuiting refrigerant around one compressor when the compressor is not operating is provided. Additionally, a quench conduit conducts liquid refrigerant from a common line to provide a liquid refrigerant quench of the gaseous refrigerant between compressors. A control device is provided for regulating the flow of liquid refrigerant through the quench conduit.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor is conducted into a heat exchanger mounted within an accumulator for supplying heat to vaporize liquid refrigerant received from the evaporator. After the gas passes through the heat exchanger it is conducted to the condenser where it is condensed to a liquid and then routed to the evaporator. In the evaporator or frost accumulating coil the liquid refrigerant is subcooled, supplying heat to melt the ice formed on the evaporator surfaces and the liquid is thereafter conducted to the accumulator where the heat supplied from the heat exchanger acts to vaporize the fluid. The vaporized refrigerant is then recycled to the compressor to complete the system.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor outlet is conducted directly into the heat exchanger to be defrosted, by-passing the condenser and thermal expansion valve to effect removal of the frost and ice accumulation on the heat exchanger surface. A portion of the hot compressor discharge gas is conducted directly into an accumulator with the liquid refrigerant received from the heat exchanger to be defrosted, the liquid refrigerant resulting from the gaseous refrigerant being condensed in the heat exchanger as the ice is melted. The refrigerant condensed to a liquid during defrost is vaporized in the accumulator thereby providing a supply of gaseous refrigerant to the compressor suction line, said gaseous refrigerant being a combination of the non-condensed discharge gas conducted to the accumulator and the liquid refrigerant vaporized in the accumulator.

Abstract: A heat exchange unit for use in an air conditioning system having an enclosure defining an opening, a heat exchanger within the enclosure and a cover adapted and mounted to the enclosure at the opening, the cover having segments extending between the center portion of the cover and the end surface such that slots are created between adjacent segments. The segments have inclined louver sections such that the air flow through the grille is optimized with the particular fan characteristics. The fan and fan motor may be secured to the center portion of the cover.

Abstract: A control circuit for a combination furnace and heat pump wherein a temperature dependent relay is connected to a thermostat such that the heat pump is operated to supply heat to an enclosure when the outdoor temperature is above a predetermined level and the furnace is operated to supply heat to the enclosure when the outdoor temperature is below a predetermined level. To defrost the outdoor coil of the heat pump the furnace is operated to supply heat to the indoor coil of the heat pump and a reversing valve relay is energized whereby the heat pump is operated in a reverse direction to supply heat to the outdoor coil for defrost.