Abstract: Disclosed are a heat pump air conditioning system comprising an additional heater and a method for operating the same, in which the additional heater is driven during a full activation standby time taken to simultaneously operate all of a plurality of compressors so as to rapidly satisfy an increased heating load. When the increased heating load exceeding a total capacity of some compressors selected from the plural compressors is sensed, since the additional heater is driven during the full activation standby time so as to rapidly satisfy the increased heating load, the air conditioning system improves heating effectiveness and uniformly maintains room temperature, thereby improving users' comfort.

Abstract: Refrigerant fluid such as CO2, compressed to the supercritical pressure by a compressor, is delivered selectively through a three-way valve, either into a branch of the circuit containing a cooler, an expansion device and an evaporator for cooling the cabin of a vehicle, or into a branch containing another expansion device and a heat exchanger for the purpose of heating the cabin.

Abstract: An energy-saving method for operating a climate control system includes reporting an ambient outside temperature from a first temperature sensor to a controller unit and reporting a climate control air temperature from a second temperature sensor to the controller unit. The control unit performs an algorithm to define a control criterion value in response to the ambient outside temperature. A non-refrigeration cycle based heating element is activated to provide heated air to an interior surface of a windshield if the climate control air temperature is above the control criterion value. Moreover, a refrigeration cycle based cooling element and the non-refrigeration cycle based heating element are activated to provide the heated air to the interior surface of the windshield if the climate control air temperature is at or below the control criterion.

Abstract: An air-conditioning system is designed at least for an air-conditioning mode for cooling a thermal control medium (13) and a heat-pump mode for heating the thermal control medium. The system comprises a refrigerant circuit with a compressor (1) and an evaporator (8), a coolant circuit with a heat-generating unit (10) to be cooled and a heater (12) for heating the thermal control medium, and also a first refrigerant/coolant heat exchanger (3) functioning on the refrigerant side as a condenser/gas cooler. The evaporator is formed by a second refrigerant/coolant heat exchanger (8). A cooling body (14) for cooling the thermal control medium is connected downstream of heat exchanger (8) on the coolant side.

Abstract: A vehicle heating and cooling system having a first coolant loop selectively connecting an engine cooling system with a heater core or a first coolant/refrigerant heat exchanger, a second coolant loop connecting a second coolant/refrigerant heat exchanger and the heater core to warm a passenger compartment of the vehicle. The system also includes a refrigerant loop that provides for conventional cooling of the passenger compartment of the vehicle, as well as operating as a heat pump, together with the coolant loops, to provide heat to the vehicle passenger compartment.

Abstract: An air conditioning system for use in an over-the-road or off road vehicle is provided that allows operation during both engine on and engine off conditions. The system utilizes a variable speed, motor driven compressor controlled by an intelligent power generation management controller. This controller selects from one of the available sources of power on the vehicle to drive the compressor, and modulates the compressor speed and capacity based on operational parameters and source availability and depletion. The controller may also operate a coolant or air heater to provide heating to the interior compartments.

Abstract: An air conditioning system for a vehicle has a first cycle including a compressor, a first condenser, a second condenser, a liquid tank, an expansion valve and an evaporator which are connected through pipes to form a first refrigerant circulation circuit through which a refrigerant flows from an outlet of the compressor to an inlet of the compressor while changing the phase. The first cycle causes the evaporator to act as a cooler when operated. The system further has a second cycle including the compressor, the second condenser, the liquid tank, the evaporator and the evaporator which are connected through pipes to form a second refrigerant circulation circuit through which the refrigerant flows from the outlet of the compressor to the inlet of the compressor while changing the phase. The second cycle causes the condenser to act as a heater and the evaporator to act as a cooler when operated. The first and second cycles are switched by switch means.

Abstract: An apparatus for heating the interior compartment of a vehicle, the apparatus has a primary heating system, a secondary heating system and an operating system. The primary heating system receives and circulates an engine coolant through a heater core. The secondary heating system receives and circulates a gas, the secondary heating system heats the gas and circulates the heated gas through a heat exchanger. The operating system for operating the heating systems, the operating system receives a plurality of inputs and in response to the inputs the operating system determines which of the heating systems is to be activated in response to a heating request. The operating system also determines whether or not to deactivate one or both of the heating systems.

Abstract: An improved vehicle heating and air conditioning system includes a driver-manipulated temperature selector that is physically coupled to a discharge temperature control mechanism. The selector is operable in a normal mode in which movement of the selector away from a full cold setting produces a corresponding movement of the temperature control mechanism that increases the discharge air temperature by re-heating or a high fuel efficiency mode in which movement of the temperature selector away from the full cold setting allows the temperature control mechanism to remain in a full cold position for a limited range of selector movement while the discharge air temperature is increased by capacity reduction of the refrigerant compressor. The temperature selector is in the form of a rotary knob that is axially shiftable to change modes when the selector is positioned at the full cold setting and spring-biased so that the normal mode is established as the default mode.

Abstract: The invention relates to an installation for utilizing surplus heat from a power transformer. A first pipe system (7) is connected to the cooling device of the transformer for circulation of a first, heat carrying fluid between the transformer and a heat pump (5) with the purpose of enabling emission of heat to an evaporator (10) included in the heat pump, which evaporator via a second pipe system (11) containing a second fluid communicates with a compressor (12), a condenser (13) and an expansion valve (14), a third pipe system (15) having a third, heat carrying fluid for transfer of heat to one or more consumption units (16) being connected to the condenser.

Abstract: An air conditioner having a low-pressure switch and a power supply unit. The low-pressure switch shuts off the supply of power to an indoor unit if a refrigerant pressure in a suction side of a compressor is decreased. The power supply unit supplies power to the indoor unit of the air conditioner so that a heating operation is performed using an electric heater mounted in the outdoor unit even though the low-pressure switch is turned off. The power supply unit may supply power to the indoor unit if an outdoor air temperature is equal to or lower than a preset reference temperature.

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: 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 heating mode in which the interior heat exchanger is operated as a radiator for heating air. In the vehicle air conditioner, an accumulator, for separating gas refrigerant and liquid refrigerant from each other and for storing the separated liquid refrigerant therein, is disposed between an outlet of the interior heat exchanger and a suction port of a compressor. Further, the accumulator includes a heating device for heating the liquid refrigerant stored in the accumulator in the heating mode. Therefore, heating performance for heating air in heating mode can be efficiently improved.

Abstract: A vehicle air conditioning system prevents the air quality from an air conditioner from becoming worse and also prevents the manufacturing cost of heat exchangers such as an interior heat exchanger, from increasing. The vehicle air conditioning system allows a heat pump unit to be operated at the maximum heating ability within a limit of the pressure resistance of the interior heat exchanger when the hot water temperature is lower than a predetermined temperature. If the temperature of hot water is equal to or higher than a predetermined temperature, the heating ability of the heat pump unit decreases with an increasing temperature of the hot water. Thus, high-pressure refrigerant cannot continuously flow through the interior heat exchanger for a long time period, so that a sufficient pressure resistance can be obtained without excessively setting the pressure of the interior heat exchanger.

Abstract: A device and a method are provided for heating and cooling a compartment of a motor vehicle powered by an internal combustion engine. The device has a coolant circuit with a compressor, an ambient heat exchanger, at least one expansion device, an interior heat exchanger, and an exhaust heat exchanger that can be heated by exhaust gases from the engine. During heating, a coolant is guided through the compressor and through the interior heat exchanger connected downstream from the compressor, releasing heat. The compressor, interior heat exchanger, expansion device, ambient heat exchanger, and heat exchanger are connected in series so that the coolant is expanded in the expansion device to a temperature below an intake temperature of coolant into the compressor, exposed in the ambient heat exchanger to warmer ambient air, heated in the heat exchanger by the exhaust gases from the engine, and compressed in the compressor.

Abstract: An environmental test chamber provides a fast cool down to a temperature of about −125° F. and a fast heat up of an element under test. The environmental test chamber fast cool down and heat up system comprises: an environmental test chamber having a fast cool down evaporator and fast heat up condenser coil, wherein the coil is selectively coupled either to receive a hot refrigerant gas flow or to receive a sub-cooled refrigerant flow; a cascade condenser coupled to the environmental test chamber; a primary stage sub-system coupled to the cascade condenser; a secondary stage sub-system coupled to the cascade condenser; and a thermal storage unit coupled to the primary stage sub-system and to the secondary stage sub-system. Wherein the environmental test chamber has an operational temperature down to about −125° F.

Abstract: A heat pump system using air as its heat source is disclosed. In this system, the refrigeration circuit consists of both a main refrigerant line and a refrigerant suction line. A heat accumulator, containing both a heat medium and a heat storage phase change material, is mounted on the refrigerant line at a position between the cooling mode and heating mode expansion valves. A heat-dissipating heat exchanger is mounted on the main refrigerant line, and is set in the accumulator. A subsidiary heat exchanger is installed around the inlet port of the outdoor heat exchanger, and is connected to the heat accumulator through heat medium lines with a circulating pump. The system also has a heat pipe consisting of both an evaporating part installed at the periphery of the heat-dissipating heat exchanger, and a heat dissipating part installed at the periphery of the heat accumulator and connected to the evaporating part through a connection pipe.

Abstract: In order to obtain more enhanced air heating capacity during low outdoor air temperature, a gas heat pump type air conditioning device which circulates refrigerant by a compressing device of which driving source is a gas engine, forms a refrigerating cycle, collects waste heat of exhaust gas exhausted from the gas engine to engine coolant water by an exhaust gas heat exchanging device, and heats the refrigerant by the engine coolant water to enhance the heating capacity, the exhaust gas exhausted from the gas engine is heated, and a heating device for increasing amount of thermal energy which can be collected in the exhaust gas heat exchanging device is provided.

Abstract: In a cooling cycle including a compressor, a gas cooler, a throttling device, and an evaporator, a heat exchanger is arranged between the compressor and the throttling device for carrying out heat exchange through a refrigerant compressed by the compressor.

Abstract: The absence or shortage of a heat transfer medium can be detected without any time lag. While the medium is circulated through a water jacket and an exhaust gas heat exchanger 9 which receives heat from the exhaust gas, the heat generated by the engine 2 can be recovered. A first sensor TW1 is provided at a waste heat recovering location in a circulation path 12 of the medium. A second sensor TW2 is provided at the downstream of the sensor TW1. When the medium is absent, there is developed a difference in the temperature measurement between the sensor TW1 and the sensor TW2 which is greater than a reference level. A heat transfer medium shortage signal is outputted when a difference in the temperature measurement between the first sensor TW1 and the second sensor TW2 exceeds the reference level.

Abstract: A heat exchanger is assembled in a simple and cost-effective way and needs a relatively low space requirement. According to the invention, the tubes (11) are expanded at the tube ends (16) in such a way that the tube ends (16) are of rectangular design in cross section. The tube ends (16) have parallel long connecting surfaces (18) which are brought into bearing contact with long connecting surfaces (18) of adjacent tube ends (16). Furthermore, the tube ends (16) have short connecting surfaces (22), onto which the collecting tanks (23, 29) are placed with their legs (24, 25) or collars (30, 31). A space-saving heat exchanger can be produced in a simple way by soldering the long connecting surfaces (18) together, on the one hand, and by soldering the short connecting surfaces (22) to the collecting tanks (23, 29), on the other hand.

Abstract: A heat pump type air conditioner for a vehicle has a refrigeration cycle constituted by a compressor, an external heat exchanger, a refrigerant valve unit and an internal heat exchanger unit. The refrigerant valve unit includes first and second flow control valves, and the internal heat exchanger unit includes an auxiliary internal heat exchanger and a main internal heat exchanger. In the refrigeration cycle, the first flow control valve, the auxiliary internal heat exchanger, the second flow control valve and the main internal heat exchanger are serially connected in the order of mention. The main and auxiliary internal heat exchangers change their function between an evaporator and a condenser according to the controlled state of the first and second flow control valve.

Abstract: An object of the present invention is to provide an outdoor heat exchanger unit which is hardly effected adverse effects of the gas engine waste heat during the cooling operation and which can improve an efficiency of the refrigerant cycle, and which can improve the heating ability by utilizing the gas engine waste heat; an outdoor unit comprising the outdoor heat exchanger unit; and an air conditioner comprising the outdoor heat exchanger unit; in order to achieve the object, the present invention provide an outdoor heat exchanger unit for a gas heat pump type air conditioner, in which a compressor for compressing a refrigerant is driven by a gas engine, and which comprises a heat pump for utilizing waste heat of said gas engine to perform a heating and a cooling operations: wherein said outdoor heat exchanger unit comprises a radiator provided in a cooling water system in which cooling water for said gas engine circulates and an outdoor heat exchanger apparatus provided in a refrigerant circuit in which sai

Abstract: An integrated compression based heating/cooling, humidification and mid or high efficiency heat recovery ventilation system is provided. The integrated system is a centralized apparatus that offers a very efficient method for heating/cooling with more winter and summer humidity control plus offering heat recovery ventilation in a structure having a regulated indoor temperature and specific ventilation/energy recovery rate. The heating and cooling section of the apparatus would most commonly be configured as a forced air geothermal or air-to-air heat pump. The heat recovery ventilation section of the apparatus will incorporate a heat recovery chamber complete with a primary passive cross flow heat recovery core. Plus, a secondary refrigeration based high efficiency reversible energy recovery evaporator/condenser coil. The integrated system will also incorporate a humidification system designed to operate during the winter heating season.

Abstract: The device of the invention comprises a closed circuit (10) in which a refrigerant fluid circulates between an evaporator (12) and a condenser (14) which are respectively in thermal contact with a cold-liquid duct (22) and a hot-liquid duct (24). Changeover-switching means (34, 36) put these two ducts into communication either with a first loop (26) travelled by a liquid and containing a heat exchanger (28) capable of being swept by an airflow (F1), or with a second loop (38) travelled by a liquid and comprising a heat exchanger (42) suitable for being swept by an airflow (F2) to be sent into the passenger compartment (H) . The heat exchanger (42) of the second loop (38) can thus heat up or cool the airflow (F2).

Abstract: The air heating capability of an indoor heat exchanger is limited to set the temperature of the indoor heat exchanger to a first predetermined temperature Tel or lower during heating. Thereby, fogging is prevented through re-evaporation of the condensed water in the indoor heat exchanger during heating within an air-conditioning apparatus with a hot water heater core using hot water as the heat source and the heating circuit.

Abstract: A compressor, an outdoor heat exchanger, an indoor heat exchanger, and the like are connected to each other with refrigerant piping to form a refrigerant circuit in a closed loop configuration. The refrigerant circuit is provided with a four-way switch valve such that the direction of circulation of a refrigerant is reversible. The refrigerant circuit is provided with a refrigerant heater. During a cooling operation, an electromagnetic valve is closed so that the outdoor heat exchanger serves as a condenser to perform a refrigeration cycle operation. During a heating operation, natural gas is caused to burn in the refrigerant heater to heat and evaporate the refrigerant with high-temperature combustion gas. The evaporated refrigerant flows into the indoor heat exchanger, exchanges heat with indoor air, and is condensed, whereby the indoor air is heated.

Abstract: An air conditioning system has a refrigerant cycle, a coolant cycle, a refrigerant/coolant heat exchanger, coupling these cycles so as to transfer heat, and valve for operating mode-dependent control of the refrigerant flow, whereby the air conditioning system can be operated not only in air conditioning mode but at least also in a heat pump or reheat mode. An internal combustion engine exhaust gas/coolant heat exchanger is connected upstream in series to the refrigerant/coolant heat exchanger in the coolant cycle at least in the heat pump mode; and/or in the reheat operating mode the refrigerant/coolant heat exchanger functions as a condenser/gas cooler, connected upstream in series on the coolant side to the supply air/coolant heat exchanger. In addition or as an alternative, a drying operating mode can be provided for drying the supply air/refrigerant heat exchanger with reversed air conveying direction.

Abstract: A heating and air conditioning unit of a motor vehicle has a heat exchanger that can be supplied with coolant of the engine and a compressor disposed in the refrigerant circuit of the air conditioning unit for the compression of a gaseous refrigerant. The heat exchanger 3, apart from the exchanger region 6 through which the coolant flows, has a separate exchanger region 7 for the heated refrigerant, which can be supplied with heated refrigerant via a bypass line 14 branching on the pressure side of the compressor 8 from the refrigerant circuit. The bypass line 14, after passing though the heat exchanger 3, discharges on the suction side of the compressor 8 again into the refrigerant circuit.

Abstract: A method and device for controlling the operation of a heat pump having a primary heat system and an auxiliary heat system, and used to heat air circulating in an enclosure such as a building, the invention comprising a first sensor positioned in the return duct of the heating system for measuring the temperature of air being returned to the heat system from the enclosure, a second sensor for measuring the temperature of air which has been heated only by the primary heat system, a temperature comparing relay for comparing the two sensed temperatures and determining the difference between them and actuating the auxiliary heat system only when the temperature difference is less than a predetermined set point, for example 4° F., thereby providing a significantly enhanced operating efficiency of the heating system.

Abstract: A method and apparatus for producing laminated plastic cards, which carry printed matter protected by an overlying layer of transparent plastic material. The picture is formed by conventional laser printing means on a substrate constituted by a plastic material that is sensitive to the combined application of heat and pressure, but is only partially set by radiant heat; thereafter a transparent coating film or sheet is juxtaposed to the printed face of the substrate, and optionally another such film is juxtaposed to its rear face, and the substrate is bound to the film or films by the application of pressure and heat to bind them together.

Abstract: A thermostat for operating a climate control system, the thermostat comprising a base, a bi-color LED on the base capable of producing at least two distinct illuminated signals, and a cover for the base, the cover having a single signal opening which is aligned with the bi-color LED when the cover is on the base to provide at least two distinct lighted signals in a thermostat through a single signal opening in the cover.

Abstract: An air conditioning system includes one outdoor unit and at least one indoor unit connected to each other. The outdoor unit has a variable capacity compressor, a four-way valve, an outdoor heat exchanger, and a refrigerant heater, while the indoor unit has an indoor heat exchanger. A saturation temperature calculator computes the saturation temperature at the refrigerant heater outlet pressure. A refrigerant heater outlet temperature detection circuit detects the refrigerant temperature near the refrigerant heater outlet. A superheating calculator calculates refrigerant superheating at the refrigerant heater outlet based on values supplied thereto from the refrigerant heater outlet temperature detection circuit and saturation temperature calculator. A compressor frequency control circuit then adjusts the compressor frequency so that the calculated refrigerant superheating is maintained at a specific level.

Abstract: Described is an apparatus for air conditioning a passenger compartment of an automotive vehicle which achieves a quick warming-up of the passenger compartment. In the air conditioning apparatus, in addition to a coolant of a vehicular engine which is utilized as a heat source of a heater core, a highly compressed refrigerant discharged from a compressor can be utilized as a heat source of a sub condenser which is disposed in an air passage of the air conditioning apparatus, during the inside air warming up in the passenger compartment. During the warming up operation, the refrigerant discharged from the compressor is circulated through a bypass line bypassing a condenser disposed at a front part of an engine compartment and through the sub condenser and an evaporator.

Abstract: An air conditioning apparatus for a vehicle seat includes a seat blower unit disposed in a lower side of the seat, and a seat duct for leading air from an air conditioning unit to the seat through the seat blower unit. In the air conditioning apparatus, it can be determined that heat load of a passenger compartment is decreased to a predetermined value based on an operation state of a unit blower of the air conditioning unit, and the seat blower is stopped when the heat load is decreased to the predetermined value. Further, the seat blower is turned on or off according to the heat load of the passenger compartment, so that temperature of the seat can be controlled within a predetermined range.

Abstract: A multi-room air conditioning system includes an outdoor unit and a plurality of indoor units connected in parallel to the outdoor unit. A compressor frequency and combustion control calculator reads a load level for each indoor unit from a load coefficient table using a differential temperature calculated by a differential temperature calculator and a rated capacity stored in a rated capacity memory. The compressor frequency and combustion control calculator then multiplies a sum of the load levels by a predetermined constant and adds a compensation value thereto to obtain a frequency value. This value is used to control the compressor. The compressor frequency and combustion control calculator also sets a target combustion level using the frequency value for control of a refrigerant heater mounted in the outdoor unit.

Abstract: A heating system control unit is provided for use with a heating system. The control unit includes a switching element connected to a first temperature switch associated with a first stage heater, a second temperature switch and a second stage heater of the heating system. The switching element is adapted for actuating the second stage heater upon the receipt of the second temperature signal and further continuing the actuation of the second stage heater until the lack of receipt of both the first temperature signal and the second temperature signal. A thermostat on the outdoor coil serves to pass the signal from the second temperature switch only upon a temperature of the outdoor coil being below a predetermined amount of about 25 degrees Fahrenheit.

Abstract: An air conditioning system is provided. A driving force is constantly transmitted to a clutchless compressor via a pulley. A condenser causes a high-temperature and high-pressure gaseous refrigerant compressed by the clutchless compressor to change to a high-pressure liquid refrigerant through heat exchange with external air. An expansion valve adiabatically expands the liquid refrigerant to thereby change the liquid refrigerant into a low-pressure atomized refrigerant. An evaporator evaporates the atomized refrigerant through heat exchange with the external air. The evaporator is heated when a thermal load on the compressor is low.

Abstract: A thermostat which is configurable to be used with conventional fossil fuel furnaces, electric furnaces, heat pumps and other air conditioning equipment and fans. A setup program is included which requires an installer to enter data specific to the type of HVAC plant installed in the building with the thermostat.

Abstract: A heat exchange unit having a first heat exchanger 23 serving as an air heat source, a second heat exchanger 26 which is supplied with fluid such as hot water or the like to heat refrigerant, and a fluid amount adjusting mechanism 30,33 for adjusting the amount of the fluid to be supplied to the second heat exchanger, an air conditioner having the heat exchanger unit, and an air conditioning system having the air conditioner. The second heat exchanger 26 is disposed in a surplus space which is formed by the first heat exchanger 23 and an air blower 41 for promoting heat exchange between the air and the refrigerant flowing in the first heat exchanger 23. The upper portion of the case of the second heat exchanger 26 is provided with a fluid outlet port 100 and a refrigerant outlet port 101 while the lower portion of the case of the second heat exchanger 26 is provided with a fluid inlet port 103 and a refrigerant inlet port 104.

Abstract: A system (10) for increasing the temperature of air initially delivered by an existing heat pump system (100) is provided which may be easily added to the existing heat pump system. System (10) includes a heat pump comfort controller (12) having a plurality of control signal leads (14, 16, 18 and 20) which are coupled in parallel relationship with a respective plurality of control signal leads (114, 116, 118 and 120) of heat pump system (100) interconnecting the heat pump indoor unit (110) with the heat pump outdoor unit (112). Heat pump comfort controller (12) includes a thermostat (50) for sensing the outdoor ambient air temperature and includes a contact (52) that closes when the outdoor ambient temperature falls below a predetermined value, conducting a control signal from the lead (14) for signaling the energization of supplemental heating units (132) of heat pump system (100).

Abstract: A heat pump system usable as an air-conditioning apparatus, a refrigeration apparatus, or a temperature-conditioning apparatus, having stable cooling, heating, or freezing capacity without significant influence from the difference in height between the expansion valve and the compressor, and the length of piping of the refrigerant circulation line, which system comprises a pressure sensing means for measuring the pressure in the refrigerant line immediately upstream of the expansion valve; optionally a pressure sensing means for measuring the pressure in the refrigerant line immediately downstream of the compressor; and an energy-supplying mechanism for exerting energy onto the refrigerant when the measured pressure is lower than a predetermined value, thereby controlling the pressure in the high pressure refrigerant line.

Abstract: An air-conditioning apparatus forms a refrigerating cycle with a refrigerant heater and a compressor having two cylinders. The apparatus simultaneously carries out a refrigerant heating operation and a heat pump operation when a required heating capacity is high, and when the required heating capacity is low, only the heat pump operation. This operation technique helps reduce the size of the apparatus and expand a variable width of heating capacity. The apparatus also has a defrosting unit for defrosting an outdoor heat exchanger during the heat pump operation.

Abstract: A supplementary thermal system controller for assisting a main system controller in retaining a desired temperature rise by monitoring the temperature in the return duct, wherein the supplemental controller comprises a microcontroller for reading and processing return duct temperature measurements, a signal conditioner circuit for preparing temperature related signals for processing by the microcontroller, processor readable medium of program code for determining the rate of temperature change in the return duct and providing control signals based on the rate of temperature change, and a supplemental thermal source driver for controlling a supplemental thermal source, such as electrical resistance heating elements, to cause the assisting temperature source to increase or decrease its thermal output.

Abstract: A heat pump type air conditioner for an automotive vehicle includes a vapor-compression refrigeration system which is provided with a compressor. An outer condenser and an inner condenser are serially connected to the compressor through a three-way valve. A bypass passage of the outer condenser communicates the compressor and the inner condenser through the three-way valve. The inner condenser is connected to an inner evaporator through an expansion valve. A refrigerant heater for heating refrigerant of the system is disposed upstream and/or downstream of the inner evaporator. The refrigerant heater is controllably operated by a control unit according to a refrigerant condition indicative signal from a refrigerant condition detector. Therefore, the air conditioner generates a sufficient heating performance even just after the start of an engine of the automotive vehicle while realizing a dehumidifying heating.

Abstract: An improved heat pump system of the type having a thermostat capable of generating at least three stages of demand signals, outdoor and indoor heat exchange coils, at least one fan, a compressor, an expansion device, with the flow of refrigerant being reversible for purposes of selecting between heating and cooling modes of operation and a supplemental heater having a plurality of supplemental heating units for further heating an air stream passing over the indoor coil through an air supply plenum to supply air to a comfort space. An improvement in this system where each of the supplemental heating units has a unique heating capacity; a combination of supplemental heating units can be selected that is responsive to a demand for heat from the thermostat; and the selected supplemental heating units are turned on appropriately so that the level of heat demand by the thermostat is provided.

Abstract: An air conditioner for vehicles that prevents icing and lack of visibility from developing on window glass of a vehicle during heating, and which permits a dehumidifying operation to be made without lowering of the air blowing temperature. The air conditioner is of a heat pump type comprising a compressor, an exterior heat exchanger, and a first interior heat exchanger, which are provided together with a second interior heat exchanger used as a heat radiator at least during heating. Further, piping lines are provided for introducing a refrigerant gas for passage through the second interior heat exchanger to the exterior heat exchanger through an expansion means, and for introducing the refrigerant gas for passage through the second interior heat exchanger to the first interior heat exchanger through a first expansion means.