Abstract: An evaporator condensate pan has a condensate trap incorporated therein to thereby eliminate the need for the installation of the separate component. A well structure is provided in the bottom wall of the condensate pan and an additional depending wall structure is provided such that the depending wall, together with a side wall of a well, define a passage way which retains a column of water for preventing the flow air into the condensate pan while allowing the flow of condensate out of the pan. Provision is made for such a combination discharge drain and trap in either a side or bottom wall of the condensate pan.

Abstract: A flue gas heat pump is provided for extracting heat from the discharged hot flue gas of a furnace. The heat pump includes a condenser at the inlet of the furnace cabinet in heat transfer relation with the flow of air to be conditioned, and an evaporator disposed at the outlet of the furnace heat exchanger for extracting heat therefrom. A compressor is provided for compressing a refrigerant and delivering it to the heat exchangers. The compressor is located in the flow path of the air to be conditioned so that the heat generated by the compressor is transferred thereto.

Abstract: A method and apparatus for regulating an economizer damper using indoor fan air pressure is disclosed. The economizer control includes dampers powered by a motive source regulated by air pressure. An outdoor ambient thermostat and a mixed air thermostat are utilized to regulate the air pressure supplied to the motive source to effectively regulate the damper position.

Abstract: Apparatus and a method for providing a combination of non-reverse and reverse defrost for a refrigeration circuit are disclosed. A three-way valve is provided for initially circulating hot gaseous refrigerant directly from the compressor to the heat exchanger requiring defrost. An intermediate header is provided as part of the internal circuiting of the outdoor heat exchanger, said intermediate header serving to direct hot gaseous refrigerant from the three-way valve into all of the circuits of the outdoor heat exchanger simultaneously to effect defrost thereof. If, after a predetermined time period, the first mode of defrost directing hot gaseous refrigerant directly to the outdoor heat exchanger fails to accomplish defrost then the three-way valve is returned to its original position and the system is operated in a second defrost mode with the reversing valve being changed such that the system operates in the cooling mode and the outdoor heat exchanger serves as a condenser until defrost is completed.

Abstract: Apparatus and method for preconditioning makeup air supplied to an air conditioning unit. An add-on preconditioning unit having a separate vapor compression refrigeration circuit is disclosed for heating or cooling makeup air supplied to an air conditioning system.

Abstract: Apparatus and a method for providing a combination of non-reverse and reverse defrost for a refrigeration circuit are disclosed. A three-way valve is provided for initially circulating hot gaseous refrigerant directly from the compressor to the heat exchanger requiring defrost. An intermediate header is provided as part of the internal circuiting of the outdoor heat exchanger, said intermediate header serving to direct hot gaseous refrigerant from the three-way valve into all of the circuits of the outdoor heat exchanger simultaneously to effect defrost thereof. If, after a predetermined time period, the first mode of defrost directing hot gaseous refrigerant directly to the outdoor heat exchanger fails to accomplish defrost then the three-way valve is returned to its original position and the system is operated in a second defrost mode with the reversing valve being changed such that the system operates in the cooling mode and the outdoor heat exchanger serves as a condenser until defrost is completed.

Abstract: Apparatus and method for preconditioning makeup air supplied to an air conditioning unit. An add-on preconditioning unit having a separate vapor compression refrigeration circuit is disclosed for heating or cooling makeup air supplied to an air conditioning system.

Abstract: A heat pump system includes a compressor, indoor and outdoor coils and a four-way valve for automatically reversing refrigerant to provide cooling or heating mode of operation. Each coil has a plurality of heat transfer circuits arranged in series when the coil operates as a condenser, and in a parallel when the coil operates as an evaporator. A second four-way reversing valve is provided in the refrigerant circuit between outlets of indoor and outdoor coils to direct refrigerant through liquid lines of the refrigerant circuit from the outlet of one coil used as a condenser to the expansion means of the other coil used as an evaporator. The second four-way reversing valve is arranged in the refrigerant circuit to connect some of heat transfer circuits connected in parallel in each coil when it is used as an evaporator, to the suction line of the compressor.

Abstract: Apparatus comprising a combination tube support for supporting tubes within a shell and tube type heat exchanger and baffle for directing fluid flow within the heat exchanger. A baffle lip is mounted on a baffle body to provide a seal with the interior surface of the heat exchanger shell. A foot having support surfaces of varying heights is used to support the baffle body to prevent the weight of the baffle body and the tubes contained therein as well as other forces from collapsing a portion of the baffle lip.

Abstract: A method and apparatus for controlling a multiple compressor heat pump system such that when the system is in the heating mode of operation the compressors are cycled individually depending upon the ambient temperature level and are individually co-ordinately operated in a defrost mode. The electrical control means disclosed provides for a second compressor being energized when the outdoor heat exchanger of a first compressor is being defrosted and the first and second contact means located within the individual defrost circuits for the first and second outdoor heat exchangers such that when the first outdoor heat exchanger is being defrosted the second outdoor heat exchanger may not commence a defrost cycle and when the second compressor is being operated in a defrost cycle a first compressor may not commence a defrost cycle.

Abstract: Apparatus for and a method of operating a high performance shell and tube type heat exchanger utilizing tubes having integral internal fins. A specific tube circuit configuration is selected to limit the temperature drop of the refrigerant within the tube to a preselected range as the refrigerant flows through the circuit.

Abstract: Electrical control means for use in a heat pump system having dual compressors wherein the operation of each compressor can be staged independently and automatically except for those periods when the outdoor heat exchanger is undergoing defrost wherein both compressors are placed in operation.

Abstract: A flow divider for use in a direct expansion heat exchanger coil as typically utilized in an air conditioning system. The divider is adapted to receive an entering flow of refrigerant from a first circuit and equally distribute the flow into a plurality of leaving circuits. The geometry of the divider is arranged so that the force of gravity acting upon the working fluids passing therethrough is negated thereby enhancing the ability of the divider to produce an equal flow distribution in each of the leaving circuits.

Abstract: A heat exchanger for use in a reversible refrigeration system. The exchanger is divided into a plurality of heat transfer zones containing one or more circuits. Control means are provided to route refrigerant through each zone in a series progression when the heat exchanger is serving as a condenser. The flow geometry is automatically changed when the function of the exchanger is reversed from condenser to evaporator so that refrigerant flows simultaneously through each of the heat transfer zones.

Abstract: A reversible vapor compression system having control means associated therewith for automatically routing refrigerant through the heat exchangers in response to a system mode of operation to produce optimum system performance when the system is called upon to produce either heating or cooling.

Abstract: A protection system for an electric motor including a safety switch to deenergize the motor upon the occurrence of a potentially deleterious operating condition. The protection system includes a current sensitive device in series with the motor. The device is deenergized when the motor is deenergized due to the occurrence of the deleterious operating condition. The protection system further includes a holding device having a normally closed switch electrically connected thereto. The holding device is energized and its switch is opened when the current sensitive device is energized. The holding device remains energized, even though the current device is deenergized, to prevent the motor from being reenergized. The holding device is deenergized to permit reenergization of the motor by the manual opening of a switch connected in series therewith.

Abstract: A reversible vapor compression system having control means associated therewith for automatically routing refrigerant through the heat exchangers in response to a system mode of operation to produce optimum system performance when the system is called upon to produce either heating or cooling.

Abstract: A heat exchanger for use in a reversible refrigeration system. The exchanger is divided into a plurality of heat transfer zones containing one or more circuits. Control means are provided to route refrigerant through each zone in a series progression when the heat exchanger is serving as a condenser. The flow geometry is automatically changed when the function of the exchanger is reversed from condenser to evaporator so that refrigerant flows simultaneously through each of the heat transfer zones.

Abstract: A heat exchanger for use in a reversible refrigeration system. The exchanger is divided into a plurality of heat transfer zones containing one or more circuits. Control means are provided to route refrigerant through each zone in a series progression when the heat exchanger is serving as a condenser. The flow geometry is automatically changed when the function of the exchanger is reversed from condenser to evaporator so that refrigerant flows simultaneously through each of the heat transfer zones.

Abstract: A reversible vapor compression system having control means associated therewith for automatically routing refrigerant through the heat exchangers in response to a system mode of operation to produce optimum system performance when the system is called upon to produce either heating or cooling.