Abstract: A heat pump system is disclosed that utilizes one or two compressors and multiple heat exchangers to provide forced air heating, radiant heating and/or water heating for an interior space. A controller directs energy to these multiple system outputs to provide maximum comfort, effectively utilize any excess energy, address fluctuations in energy output, prevent unsafe operating conditions and avoid intermittent compressor operation. The system may provide energy for a water heater in both heating and cooling mode, and control operation of the water heater to utilize system energy whenever possible and avoid use of a conventional water heater heating element. Load Management Control is also provided so that the system may be shut down remotely by a utility company.

Abstract: A simultaneous cooling-heating multiple type air conditioner includes a plurality of cooling-heating combined-use indoor units controlled in an operation domain divided into a plurality of operation zones based on a refrigerant suction pressure and a refrigerant discharge pressure of a compressor. The operation domain includes three operation zones. In the first operation zone, a cooling-initiative simultaneous cooling and heating operation mode is switched to a heating-initiative simultaneous cooling and heating operation mode. In the second operation zone, the cooling-initiative simultaneous cooling and heating operation mode or the heating-initiative simultaneous cooling and heating operation mode, does not switch to different modes. In the third operation zone, the heating-initiative simultaneous cooling and heating operation mode is switched to the cooling-initiative simultaneous cooling and heating operation mode.

Abstract: Disclosed herein is a flash tank of a two-stage compression heat pump system that can perform cooling and heating with a separate type intercooler and a high-stage compressor protecting device. The system comprises a fluid-level detecting sensor for detecting the fluid-level of the refrigerant, an alarm sensor for notifying the saturated state of the refrigerant filled in the flash tank, an evaporator pressure sensor for measuring and notifying the pressure of the refrigerant flowing into the evaporator, a condenser pressure sensor for measuring and notifying the pressure of the refrigerant flowing out of the condenser, a flash tank fluid-level controller for receiving signals from the above sensors and controlling intermediate pressure and the fluid-level of the flash tank, and a bypass valve controller for controlling a bypass valve that receives signals from the alarm sensor and allowing a refrigerant to directly flow from the low-stage compressor to the high-stage compressor.

Abstract: A method for controlling a stop operation of an air conditioner having a compressor, a four-way valve, an electronic expansion valve (EEV), an indoor fan and an outdoor fan includes the steps of stopping the operations of the compressor and the indoor fan if an operation stop signal is inputted during a heating operation; and checking an amount of elapsed time after the turn-offs of the compressor and the indoor fan, and turning off the EEV and the outdoor fan if the amount of elapsed time reaches a preset reference time. The methods also includes the steps of detecting pressures at an inlet side and at an outlet side of the compressor to calculate a pressure difference; and turning off the four-way valve if the calculated pressure difference reaches a preset reference pressure difference.

Abstract: A problem to be solved by the present invention is that the temperature of a refrigerant discharged from a compression section can be detected more exactly without being influenced by variable factors existing around the compression section. In a rotary compressor 1 having a motor 6 and a compression section 3 provided in a closed container 2, and also having a discharge pipe 26 provided in an upper part of the closed container 2 to discharge a refrigerant compressed by the compression section 3 to the outside of the closed container 2, a refrigerant discharge part 462 for discharging the refrigerant compressed by the compression section 3 toward the inner peripheral surface of the closed container 2 is provided, and a discharge temperature sensor 20 for detecting the discharge temperature of compressed refrigerant is arranged in a portion opposed to the refrigerant discharge part 462 on the outer peripheral surface side of the closed container 2.

Abstract: The present invention provides a heat pump including: a compressor; a radiator; a first throttling device having a variable opening; an expander; a second throttling device having a variable opening; an evaporator; piping that connects the compressor, the radiator, the first throttling device, the expander, the second throttling device, and the evaporator so that refrigerant circulates thorough the elements in that order; and a control device for controlling the opening of the first throttling device and the opening of the second throttling device. This heat pump is capable of independently controlling the pressure of the refrigerant flowing into the expander (intermediate pressure) and pressure in a high-pressure side of a refrigeration cycle, and also is capable of size reduction, or in some cases elimination, of a receiver for the refrigerant.

Abstract: A water-cooled air conditioner includes a first heat exchanger where indoor air is heat-exchanged with refrigerant, a compressor for compressing the refrigerant, an accumulator that is installed adjacent to the compressor to filter off liquid-phase refrigerant so that only gas-phase refrigerant can be introduced into the compressor, a plate-shaped second heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with the water, and a refrigerant bypassing unit that selectively operates to allow a portion of the refrigerant compressed in the compressor to be directly returned to the second heat exchanger.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: A system for defrosting an air-to-air heat pump system is disclosed. A bypass loop transfers refrigerant at a higher temperature and pressure than is normally cycled through the outdoor unit to an outdoor coil to defrost ice on the outdoor coil. The bypass loop includes a valve movable between closed and open positions. A sensor monitors a preselected condition indicative of outdoor coil performance. A controller communicates with the valve and the sensor. Once the controller determines that a preselected set point of a preselected condition indicative of deteriorating performance has been reached, the controller sends a signal to open the valve, allowing warm refrigerant to bypass expansion valves and flow to the outdoor unit to defrost the outdoor unit. Once defrosting is accomplished, the valve can be moved to a closed position to resume normal operation of the heat pump unit.

Abstract: The integrated automotive HVAC/PTC system of the present invention includes a bi-fluidic heat exchanger between an air conditioning subsystem and a heating subsystem which enables heat extracted during dehumidification of the ventilation air to be transferred into dehumidified ventilation air. The HVAC/PTC system includes reconfigurable coolant loops and reconfigurable refrigerant loops, some of which act in concert and some of which may be isolated. Power train components, including the power supply, may be grouped by heat transfer requirements and may be cooled or heated as needed. Power train cooling is accomplished with coolant in the heating subsystem chilled by the air conditioning system.

Abstract: A heat pump is operable in a heating mode and a cooling mode and includes two identical heat exchangers. The heat exchangers alternate between operating as a condenser and an evaporator as the heat pump switches between the heating mode and the cooling mode. The heat exchangers include a fluid passageway for directing a refrigerant therethrough and a bypass bisecting the fluid passageway into a first portion and a second portion. A valve interconnects the first portion and the second portion of the fluid passageway and the bypass for directing the refrigerant through the first portion of the fluid passageway and into the bypass to prevent refrigerant flow through the second portion of the fluid passageway when the heat exchanger is operable as the evaporator.

Abstract: A thermostat is provided that receives one or more inputs from at least one heating system of a climate control system, and initiates an appropriate action in response to the input. The thermostat can turn off a heat pump providing substandard heat and responsively turn on a fuel-fired auxiliary furnace. The thermostat may discontinue further operation of the auxiliary furnace upon receiving an operating error signal associated with the auxiliary furnace, and responsively turn on the heat pump to provide for continued heating. The thermostat may also discontinue operation of the fuel-fired furnace and turn on a circulating fan in response to an input signal indicating a furnace high-temperature or a carbon monoxide presence.

Abstract: A heat pump is provided with a discharge valve on a discharge line. The discharge valve can be positioned to modulate or pulse refrigerant flow from the discharge line heading toward an indoor heat exchanger, when in a heating mode. By providing this restriction, the pressure and the temperature of the refrigerant increases. This increased temperature provides additional heating capacity as well as increases the temperature of the delivered indoor air, minimizing “cold blow” and making the end user more comfortable. The use of discharge valve can also minimize or entirely eliminate the ON/OFF unit cycling, as the amount of heat delivered can be precisely controlled by pulsing or modulating the valve, thus reducing unit cycling losses, improving user comfort and enhancing reliability.

Abstract: A heat pump is provided with a method and control for eliminating compressor un-powered reverse rotation at shutdown. In particular, the position of the four-way reversing valve is changed and the heat pump is moved to the opposite mode of operation as compared to the one it had been operated before shutdown. The compressed refrigerant, that might otherwise re-expand through the compressor and cause the compressor to run in reverse, is now communicated to the suction line of the compressor, while the discharge port of the compressor communicates with a refrigerant at suction pressure. Thus the unpowered reverse rotation of the compressor is no longer possible.

Abstract: An air conditioner having a plurality of outdoor units and a plurality of indoor units with a common piping connected via a common piping to transfer refrigerant therebetween, the air conditioner including a first outdoor unit to provide heat, a second outdoor unit to defrost a heat exchanger of the second outdoor unit, and a first refrigerant guide unit in the second outdoor unit to guide a flowing direction of the refrigerant, wherein the refrigerant discharged from the first outdoor unit is circulated through the heat exchanger of the second outdoor unit.

Abstract: Disclosed herein is a control method for four-way valves of a multiple heat pump. In the control method, if even at least one of four-way valves of respective outdoor units is not switched to a desired mode upon switching of all of the four-way valves to the desired mode, the other four-way valves, switched to the desired mode, is switched to an opposite direction of the desired mode, and then all of the four-way valves are switched again to the desired mode, thereby simply and rapidly correcting switching error of the four-way valves, resulting in normal operation of the multiple heat pump.

Abstract: A driving method of an air conditioning system is disclosed. The air conditioning system includes a first cooling device combined with a heating function and having a compressor, an outdoor heat exchanger, an expansion device, a passage control device and an interior heat exchanger, a second cooling device provided at an outlet side of the blower and having a cooling pad containing moisture and ventilating, a tank storing refrigerant, a pump, a sprayer and a filter, a control unit electrically connecting to the first and second cooling devices and a humidity sensor and alternatively driving the first cooling device and the second cooling device according to humidity of outdoor air delivered from the humidity sensor during air conditioning mode.

Abstract: A heat pump four-way valve selectively routes refrigerant to either indoor or outdoor heat exchanger. The position of the plunger inside the valve can also be adjusted to selectively provide a hot gas by-pass function by routing a portion of refrigerant from discharge to suction line. The four-way valve preferably is positioned such that it can either operate in a conventional heat pump mode, or can be positioned to perform an unloaded hot gas by-pass function.

Abstract: In a vehicle air conditioner for heating a passenger compartment by a heater core and a heat pump cycle, when operation of a heat pump cycle is switched from a defrosting operation to a heating assist operation, a heating degree of the heater core is increased higher than a predetermined heating degree. Further, when the operation of the heat pump cycle is switched from the defrosting operation to the heating assist operation, an air outlet mode except for a defrosting mode for defrosting a windshield is set. Further, in the defrosting operation of the heat pump cycle, the temperature of an interior heat exchanger of the heat pump cycle is set higher.

Abstract: The invention relates to a system for cooling and heating, having a first heat exchanger (10) for outputting heat to and extracting it from a heat reservoir (12); a second heat exchanger (14) for extracting heat from and outputting it into a space (16) to be cooled or heated; a compressor (18); an expansion device (20); and means (22, 24) for switchover between a cooling mode and a heating mode; wherein the switchover means (22, 24) are integrated with a module (26). The invention also relates to a method for switching over between a cooling mode and a heating mode.

Abstract: A vapor compression system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated through the system. The high side pressure of the vapor compression system is selected to optimize the heating capacity. In one example, the optimal high side pressure is obtained by determining the high side pressure that correlates to the maximum current required to operate to the water pump. In another example, the actual temperature of the water entering the gas cooler, the water exiting the gas cooler, and the ambient air temperature are measured and compared to a predetermined value to determine the optimal high side pressure.

Abstract: A refrigeration cycle system is disclosed. Upon generation of a start signal for a hot gas heater cycle, the cooling mode is first started thereby to start the dormant refrigerant recovery mode (S10) and, upon an increase in the compressor discharge pressure Pd to a predetermined setting P1, the cooling mode is ended and the compressor is switched to the off mode (S20, S30). Upon the lapse of a predetermined time ta in the off mode, the off mode is ended (S40) and the heating mode with the hot gas heater cycle is started.

Abstract: A heat pump is provided with a single expansion device a pair of four-way reversing valves. One of the reversing valves routes the refrigerant from the compressor to either an outdoor heat exchanger or indoor heat exchanger, as well as routes the refrigerant back to the compressor. The second four-way reversing valve receives refrigerant from one of the heat exchangers and properly routes it through a common expansion device in a single direction. The two four-way reversing valves are controlled dependent on whether the heat pump is operating in a cooling or heating mode. A single expansion device sensor is positioned on a suction line, which receives refrigerant on its way back to the compressor from the first four-way reversing valve. The present invention thus eliminates the prior art requirement of additional components, enhances control and reduces system cost.

Abstract: Disclosed is a multi-air conditioner including: an outdoor unit having a compressor, an outdoor heat exchanger, and an outdoor fan for ventilating the outdoor heat exchanger; a plurality of indoor units each having an electronic expansion valve and an indoor heat exchanger; a distributor for selectively guiding a refrigerant of the outdoor unit into the plurality of indoor units according to an operation condition; a four-way valve for selectively switching a flow direction of the refrigerant flowing through the outdoor heat exchanger; a selective expansion unit for selectively expanding the refrigerant according to the flow direction of the refrigerant; a gas-liquid separator for separating a vapor-phase refrigerant and a liquid-phase refrigerant, from the refrigerant flowing from the outdoor heat exchanger; and a connection tube part having a first connection tube for connecting the four-way valve with a distributor, a second connection tube for connecting an upper portion of the gas-liquid separator with t

Abstract: When a dehumidifying and heating operation is set in an air conditioner, refrigerant is circulated from a compressor to the compressor through a first exterior heat exchanger, a decompression device, an interior heat exchanger, an another decompression device, an inner heat exchanger and a second exterior heat exchanger, in this order. Further, by controlling a throttle opening degree of the another decompression device, a refrigerant temperature in the interior heat exchanger can be set higher than that in the second exterior heat exchanger. Thus, even when the interior heat exchanger is controlled to a temperature to be not frosted, heat can be absorbed from outside air in the second exterior heat exchanger. Accordingly, when an outside air temperature is low, by setting the dehumidifying and heating operation, air to be blown into a compartment can be dehumidified while sufficiently increasing heating capacity.

Abstract: When the air blowing amount of a blower 23 is large, a high pressure is controlled so as to be increased higher than when the air blowing amount by the blower 23 is small. By this construction, refrigerant noise is drowned out by air noise and is made difficult to hear. In addition, in general, as a high heating capability is required when the air blowing amount is large and, on the contrary, a high heating capability is not required when the air blowing amount is small, in the event that the high pressure is controlled based on the air blowing amount, the noise attributed to the refrigerant noise, that is felt by the occupants when heating is performed using the hot gas, can be reduced without damaging the sense of being heated.

Abstract: Multi-type air conditioner including an outdoor unit having a compressor, an outdoor heat exchanger, a flow path control valve for controlling a flow path of the refrigerant from the compressor, an outdoor expansion device for expanding liquid refrigerant introduced thereto in a condensed state via indoor units and providing to the outdoor heat exchanger when the room is heated, and an outdoor unit piping system, a plurality of indoor units each having an indoor expansion device, an indoor heat exchanger, and an indoor piping system, a distributor for selectively distributing the refrigerant from the outdoor unit to the indoor units and returning to the outdoor unit again proper to respective operation modes, and means for super cooling the refrigerant condensed at the outdoor heat exchanger or the indoor heat exchangers and flowed to the indoor expansion devices or to the outdoor expansion device, thereby super cooling the refrigerant supplied to the evaporator.

Abstract: A method and system for heating a space includes circulating refrigerant in a closed loop system having a first heat exchanger and a second heat exchanger. The circulating step includes pressurizing liquid refrigerant to a first pressure and heating the liquid refrigerant in a third heat exchanger to form a refrigerant vapor. The method further includes compressing refrigerant by a compressor to a second pressure, wherein the compressor is at least partially driven by refrigerant vapor received from the third heat exchanger, and supplying one of the first and second heat exchangers with refrigerant from the compressor. The method further includes supplying refrigerant from the other of the first and second heat exchangers to the compressor and selectively supercharging the refrigerant supplied to the compressor from the other of the first and second heat exchangers.

Abstract: A heat pump having an indoor coil that operates as a condenser when the system is in a heating mode and an outdoor coil that operates as an evaporator when the system is in the heating mode. A variable speed indoor fan is used to move supply air over the indoor coil and a temperature sensor is arranged to provide ambient outdoor temperature data to a programmable computer. The computer contains a schedule for continuously adjusting the speed of the indoor fan in response to changes in the ambient temperature so as to maintain the temperature of the supply air at a constant level. In doing so, the compressor discharge pressure is also maintained within allowable limits and is held substantially constant.

Abstract: Disclosed is a multi-air conditioner comprising: an outdoor unit installed at an outdoor location and exchanging heat with an outdoor air, a plurality of indoor units installed at respective indoor rooms and provided therein with an indoor heat exchanger and an electronic expansion valve, and a distributor provided between the outdoor unit and the indoor units, for selectively guiding the refrigerant according to the operation mode. The outdoor unit is comprised of a compressor, a refrigerant flow control part for controlling a flow path of a compressed refrigerant according to an operation mode, an outdoor heat exchanger exchanging heat with the outdoor air, and a pipe part connecting the elements of the outdoor unit and guiding the refrigerant to the distributor. The distributor guides the refrigerant selectively to the outdoor unit and the indoor units according to the operation mode.

Abstract: The heater has increased quick responsiveness to temperature control of air, and the air conditioner can realize highly accurate temperature control using the heater. A duct unit having heat sources comprising electric lamps in the inside thereof is attached to an air duct. Air coming into contact with glass bulbs of the electric lamps is heated by radiant heat and transferred heat generated by lighting the electric lamps, whereby the heater with increased quick responsiveness to temperature control is obtained. A first heater and a second heater are provided in the air duct, respectively, and temperature sensors for controlling these heaters are attached to the air duct and a precision environment chamber, respectively, whereby temperature control in two stages with different temperature resolutions is made possible, and an air conditioner with high accuracy excellent in controllability can be provided.

Abstract: A heat pump having an indoor coil that operates as a condenser when the system is in a heating mode and an outdoor coil that operates as an evaporator when the system is in the heating mode. A variable speed indoor fan is used to move supply air over the indoor coil and a temperature sensor is arranged to provide ambient outdoor temperature data to a programmable computer. The computer contains a schedule for continuously adjusting the speed of the indoor fan in response to changes in the ambient temperature so as to maintain the temperature of the supply air at a constant level. In doing so, the compressor discharge pressure is also maintained within allowable limits and is held substantially constant.

Abstract: A vapor compression system for allowing humidity control includes a plurality of vapor compression circuits including at least one cooling circuit and at least one heat pump operable circuit; the plurality of circuits being adapted to act upon a stream of air whereby a first portion is cooled by the at least one cooling circuit and a second portion is heated by the heat pump operable circuit whereby the stream of air can be dehumidified while maintaining a desired air stream temperature. As a result, such a system can have three modes of operation; cooling, heating and dehumidification with low sensible capacity as well as multiple steps of unloading. Furthermore, system reliability and complexity are improved and operation and control functions are enhanced.

Abstract: A device is provided for monitoring a plurality of appliances, wherein each appliance is connected to an electrical circuit having a first wire and a second wire. The device includes a plurality of cores, each of the plurality of cores being constructed to be able to surround one of the first wires of each circuit and having a secondary winding at which an electrical signal is generated in response to a current polarity change in the first wire. A multiplexer is connected to the secondary winding of each of the plurality of cores. A processor is connected to the multiplexer to monitor the phase relationship between an AC voltage an AC current of each appliance connected to one of the plurality of circuits and to determine information relating to the function of the appliance based on the phase relationship. The device may be located at the circuit breaker box of an establishment.

Abstract: Indoor circuits (60, 65) of indoor units (12, 13) are each connected in parallel to an outdoor circuit (20) of an outdoor unit (11). The outdoor circuit (20) has a gas vent pipe (35) by which a receiver (23) is brought into communication with suction sides of compressors (41, 42). During the heating operation in the heating mode of operation, a gas vent solenoid valve (36) is placed in the open state so that the receiver (23) decreases in pressure. This relaxes restrictions on the difference in installation height between each indoor unit of a multi type airconditioner having a plurality of indoor units.

Abstract: A vapor compression air conditioning system, including a heat pump embodiment, provides enhanced dehumidification of supply air to an enclosed space. The refrigerant fluid circuit includes an evaporator and a reheat heat exchanger for controlling temperature and dehumidification of supply air. A variable speed fan motor controls air flow over an outdoor condenser heat exchanger whereby condenser heat exchange may be shifted progressively between the reheat heat exchanger and the condenser heat exchanger. One alternate embodiment includes a thermosiphon system for heat transfer to and from the reheat heat exchanger. Another embodiment includes a bypass air flow control damper for controlling flow of supply air through the evaporator and the reheat heat exchanger.

Abstract: When the air blowing amount of a blower 23 is large, a high pressure is controlled so as to be increased higher than when the air blowing amount by the blower 23 is small. By this construction, refrigerant noise is drowned out by air noise and is made difficult to hear. In addition, in general, as a high heating capability is required when the air blowing amount is large and, on the contrary, a high heating capability is not required when the air blowing amount is small, in the event that the high pressure is controlled based on the air blowing amount, the noise attributed to the refrigerant noise, that is felt by the occupants when heating is performed using the hot gas, can be reduced without damaging the sense of being heated.

Abstract: A refrigeration cycle system is disclosed. Upon generation of a start signal for a hot gas heater cycle, the cooling mode is first started thereby to start the dormant refrigerant recovery mode (S10) and, upon an increase in the compressor discharge pressure Pd to a predetermined setting P1, the cooling mode is ended and the compressor is switched to the off mode (S20, S30). Upon the lapse of a predetermined time ta in the off mode, the off mode is ended (S40) and the heating mode with the hot gas heater cycle is started.

Abstract: The problem of controlling the temperature of the different units in a process tool system which have to be cooled or heated using thermal transfer fluid at selected setpoints and flow rates is resolved by a system having multiple modular units each with some operative and form factor commonality but at least dual functional capability. The modular units each have separate recirculation loops for thermal transfer fluid but cool the fluid using refrigeration cycles or facilities water supplies or heat the fluid using compressed hot gases or electrical energy. By employing operative units which can be internally varied to provide different thermal capacities within form factor constraints, the system enables concurrent temperature control needs of a number of different units to be met with an energy efficient, low footprint, highly adaptable system.

Abstract: Multi-unit air conditioner including an outdoor unit including a flow path control valve for controlling a flow path of refrigerant from a compressor, outdoor heat exchanger having one side in communication with the flow path control valve, a first bypass pipeline having one end connected to the first pipeline which makes the flow path control valve and the outdoor heat exchanger to be in communication, and the other end connected to the second pipeline connected to the other end of the outdoor heat exchanger, and a flow rate control valve provided on the first bypass pipeline for controlling a flow rate of the refrigerant passing through the first bypass pipeline, an indoor unit having an indoor heat exchanger and indoor electronic expansion valve installed in each of rooms, a distributor for selective distribution of the refrigerant received through one of two pipelines connected to the outdoor unit to the indoor units, and returning to the outdoor unit through the other one pipeline, and controlling means

Abstract: A vehicle air-conditioning system of a dual air-conditioner type exhibiting a hot gas heater function, which is designed to efficiently recover not only dormant refrigerant at the heater side, but also dormant refrigerant at the rear seat evaporator, which system sets the refrigeration cycle to a cooling mode and engages in a refrigerant recovery operation when starting up the heating mode by a hot gas heater cycle, then switches the refrigeration cycle to the heating mode, sets the front seat air-conditioning unit to the outside air mode at the time of the heating mode to blow outside air to the front seat evaporator by the front seat blower, then, when judging that the inside air temperature is high due to the refrigerant temperature of the rear seat evaporator at the time of the heating mode, operates the rear side blower to blow inside air to the rear seat evaporator.

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range by using an expander which is operated in accordance with a flowing direction of refrigerant.

Abstract: Heat pump equipment comprising at least three heat exchangers, one of which is intended to be located in an enclosed region and the other two of which are intended to be located outside the enclosed region. Each heat exchanger has a delta connection end connected in heat-exchange fluid communication with a delta arrangement. The delta connection end of each heat exchanger is connected to both of the delta connection ends of the other two heat exchangers via the delta arrangement. There are three fluid-expansion devices, one between the two connections of each pair of adjacent connections of the heat exchangers to the delta arrangement. The present invention extends to heat pump equipment comprising at least three heat exchangers connected in a heat-exchange fluid circuit, one of which heat exchangers is intended to be located in an enclosed region and another of which is intended to be located outside the enclosed region.

Abstract: In the air conditioner of the present invention, both the normal cooling mode operation, in which refrigerant discharged from the compressor 1 is made to flow in the condenser 2, and the heating mode operation conducted by the hot gas bypass, in which refrigerant is made to bypass the condenser and directly flow in the evaporator 4 via the throttle 17, can be conducted. Before this heating mode operation, after the compressor is turned on for a predetermined period of time in the cooling mode, the compressor is turned off for a predetermined period of time, so that refrigerant residing in the condenser can be recovered into the hot gas cycle, and then a hot gas operation, which is the heating mode, is conducted.

Abstract: Disclosed is a method for controlling cooling/heating of a heat pump system comprising the steps of: (a) controlling a compressor so that a flow rate of a refrigerant is reduced when the heat pump system is switched from a cooling mode to a heating mode or from the heating mode to the cooling mode; and (b) controlling a four-way valve so that a flow direction of the refrigerant is converted into an opposite direction when the flow rate of the refrigerant is reduced after the step (a). The method prevents the rapid change of the flow direction of the refrigerant during the cooling/heating mode switching and reduces noise generated in the cooling/heating mode switching.

Abstract: Disclosed are an apparatus and a method for controlling compressors of an air conditioner. The apparatus includes a temperature sensor, a comparison unit, and a controller. The temperature sensor is installed close to an outdoor unit and serves to sense an outdoor temperature. The comparison unit compares the outdoor temperature sensed by the temperature sensor to a predetermined temperature. The controller determines a heating load when the comparison unit determines that the outdoor temperature is more than the predetermined temperature, and controls the operation of the plural compressors based on the determined heating load. The apparatus determines the heating load by means of the outdoor temperature, and properly operates the plural compressors depending the determined heating load, thereby improving the heating efficiency of the air conditioner.

Abstract: A humidity control method is provided for a multi-stage cooling system having two or more refrigerant circuits that balances humidity control and cooling demand. Each refrigerant circuit includes a compressor, a condenser and an evaporator. A hot gas reheat circuit having a hot gas reheat coil is connected to one of the refrigerant circuits and is placed in fluid communication with the output airflow from the evaporator of that refrigerant circuit to provide additional dehumidification to the air when humidity control is requested. The hot gas reheat circuit bypasses the condenser of the refrigerant circuit during humidity control. Humidity control is only performed during cooling operations and ventilation operations. During a first stage cooling operation using only one refrigerant circuit and having a low cooling demand, the request for humidity control activates the hot gas reheat circuit for dehumidification and activates a second refrigerant circuit to provide cooling capacity.

Abstract: A vehicle air conditioner includes a casing having an air passage from which air blows out to a passenger compartment of a vehicle, a carbon-dioxide-gas compression refrigerator including a compressor, a radiator and a evaporator, an air heater for heating air that blows out from the air passage by heat generated by the vehicle and a control unit for circulating compressed carbon-dioxide-gas through the radiator if heat energy of the air heater is less than a prescribed capacity but is sufficient to heat the air blowing out to the passenger compartment.

Abstract: In a vehicle air conditioner with a heat pump cycle having an interior heat exchanger and an exterior heat exchanger, when a frosting on a surface of the exterior heat exchanger is determined and when a temperature of hot water supplied to a heater core is equal to or higher than a predetermined temperature, the exterior heat exchanger is defrosted in a defrosting operation. Accordingly, the defrosting operation can be performed while a sufficient heating can be obtained.

Abstract: A boosted source heat pump (BSHP) is presented having a primary compressor, a booster compressor, an economizer, and a lubricant management system. At least the primary compressor is a twin-single compressor. The lubricant management system includes traps to prevent migration of lubricant to a non-operating compressor, and aspiration tubes from the sump to the low pressure intake zone to each compressor.