Abstract: In a temperature control system and method, a compressor is left on during steady state operation even when cooling is not needed, and an electronically controlled valve (e.g., a solenoid valve) is used to enable and disable the flow of coolant through a heat exchanger system in order to selectively control whether cooling is enabled or disabled. A flow of air may be passed through the heat exchanger system to cool the flow of air, and the valve may be controlled based at least in part on temperature of the flow of air, e.g., in accordance with a proportional-integral-derivative (PID) control scheme. A heater may be controlled to selectively heat the flow of air. A cooling cycle may be provided in which the heater is disabled and the flow of coolant is enabled via the valve, and a heating cycle may be provided in which the heater is enabled and the flow of coolant is disabled via the valve.

Abstract: Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

Abstract: A vehicle air-conditioning apparatus includes a dehumidification means, which has a compressor and dehumidifies inside of the vehicle, a humidity calculation means, which calculates humidity in the vicinity of an inside surface of the windshield, and a determination means, which determines whether the windshield is fogged on the basis of comparison between the humidity and a predetermined value. A defogging operation for heightening dehumidifying performance of the dehumidification means is performed, when the determination means determines that the windshield is fogged in a state where the compressor is turned on. The dehumidifying performance of the dehumidification means is lowered or condition in which the defogging operation is started is made to be difficult in the next defogging operation, when the windshield is determined to be fogged and the defogging operation is not manually performed in a state where the compressor is turned off.

Abstract: A vehicle air conditioner selectively switches one of a cooling mode in which an interior heat exchanger of a refrigerant cycle is operated as an evaporator for cooling air, and a hot-gas heating mode in which the interior heat exchanger is operated as a radiator for heating air. The cooling mode is selected by turning on an air-conditioning switch, and the hot-gas heating mode is selected by turning on a hot gas switch. When both the switches are turned on at the same time, a control unit determines a priority mode having a higher necessity among the hot-gas heating mode and the cooling mode. Specifically, the hot-gas heating mode is automatically set by the control unit when the outside air temperature is lower than a predetermined temperature, and the cooling mode is automatically set by the control unit when the outside air temperature is higher than the predetermined temperature.

Abstract: Carbon dioxide refrigerant is circulated through a vapor compression system including a compressor, a gas cooler, an expansion device, and an evaporator. Carbon dioxide is extracted from a vehicle exhaust stream that includes combustion products of burned hydrocarbon fuel. The extracted carbon dioxide is used to supplement the initial supply of carbon dioxide refrigerant to maintain a desired (or predetermined) level of refrigerant in the system. The system includes a sensor assembly that measures and monitors the amount of refrigerant in the system. In one example, the extracted carbon dioxide is automatically added to the system from a storage tank when a sensor detects that the amount of carbon dioxide refrigerant in the system is below a threshold value. In another example, the extracted carbon dioxide is directly added to the system, and the carbon dioxide refrigerant is purged from the system when a sensor detects that the amount of carbon dioxide in the system exceeds a threshold value.

Abstract: A manual reset high temperature limit thermostat is provided. The manual reset lockout feature is provided by a lock rod that is outwardly transitioned upon actuation of the thermostat when the sensed temperature reaches its high level limit. A manual reset reset slide then engages the lock rod to prevent automatic resetting of the thermostat once the sensed temperature decreases below the thermostat set point. Resetting of the thermostat once the temperature has decreased may be accomplished by sliding the switch to disengage the reset slide from the locking rod. The thermostat internal snap action mechanism then retracts the lock rod and resets the thermostat's electrical contacts.

Abstract: A driving arrangement for air refrigeration appliances, of the type comprising a fan (F), a compressor (C), a thermostat (T) and first and second selecting devices (10, 20), which are manually displaceable for activating the fan (F) and compressor (C) and for adjusting the thermostat (T). According to the invention, the first selecting device (10) is displaced along a first portion (1), at the end of which the fan (F) is turned on, a second portion (2), in which only the fan (F) is kept turned on and a third portion (3), in which beginning the compressor (C) is turned on and along which the thermostat (T) is adjusted between a minimum cold condition and a maximum cold condition. The second selecting device (20) has two operative positions, each defining a ventilation regimen for the fan (F).

Abstract: An air conditioner for an automotive vehicle having an air conditioner compressor driven with a crankpulley of an internal combustion engine, with an electromagnetic clutch energized, and linked with an evaporator for cooling and dehumidifying the intake air and an air mixing door located upstream of a heater core for heating the intake air.

Abstract: A user-operable power-up mode switch included within an electronic air conditioning mode control circuit of the type including momentarily-actuated user mode selection switches and a volatile mode selection memory. In the event of power interruption, the mode selection memory "forgets" the last selected mode after a relatively short time when power supply filter capacitors have discharged. The power-up mode switch allows user selection of the particular mode in which operation resumes upon power restoration, but the user power up mode selections do not include all the operational modes selectable by the momentarily-actuated user mode selection switches. Thus operation continues in a mode at least appropriate for the season.

Abstract: A discharge air temperature control device which is provided in an air conditioning system for automotive vehicles, the device comprising a lever assembly for adjusting the angular position of an air-mix damper, a driving circuit for driving the compressor of the air conditioning system, and a switching device for opening or closing the driving circuit in response to an air flow temperature signal supplied from a temperature sensor, characterized in that means is provided which is responsive to a change in the angular position of the lever assembly to vary a reference temperature value with reference to which the switching device opens or closes the driving circuit. The frequency of actuation of the compressor can thus be reduced to thereby save energy to be consumed by the air conditioning system.

Abstract: A self contained heating and cooling system is disclosed comprising a heat pump unit having a heat exchanger for heating and cooling air in a space, an auxiliary heating unit for heating air in the space, a support housing for the heat pump and auxiliary heating units, a cycling thermostat for governing operation of the heat pump and auxiliary heating units to enable establishment of a predetermined space air temperature, and a changeover thermostat.

Abstract: A control for a plurality of air conditioning units installed in separate rooms of a multi-room building, with each air conditioning unit having an on-off switch to selectively connect the air conditioning unit to a source of electrical power. The control includes a switch for simultaneously interrupting the electrical power supplied to each air conditioning unit to place each unit in an off state. Once the supply of electrical power to each unit is renewed, each unit is prevented from restarting until the unit's on-off switch has been manually moved from its on position to its off position.

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.