Abstract: A vehicle thermal management system, may include an HVAC subsystem including a first compressor and a first refrigeration cycle including a first refrigerant loop fluidly connected to the first compressor; a battery cooling subsystem including a battery coolant loop fluidly connected to a battery pack; a powertrain cooling subsystem including a powertrain coolant loop fluidly connected to a powertrain component; a second refrigeration cycle including a second compressor, a condenser located on the downstream side of the second compressor, and a second refrigerant loop fluidly connected to the condenser; a refrigerant chiller mounted between the first refrigeration cycle and the second refrigeration cycle and configured to transfer heat between the first refrigeration cycle and the second refrigeration cycle; and a battery chiller mounted between the second refrigeration cycle and the battery coolant loop and configured to transfer heat between the second refrigeration cycle and the battery coolant loop.

Abstract: A HVAC thermal conditioning system provides a macroclimate environment. An auxiliary thermal conditioning system has multiple microclimate devices. The microclimate devices are configured to be arranged within an interior space that provides the macroclimate environment to an occupant. The microclimate devices provide a microclimate environment to the occupant different than the macroclimate environment. The microclimate devices are in close proximity to a region of the occupant. A controller calculates an occupant personal comfort based upon a thermal energy experienced by the occupant from thermal radiation sources, thermal convection sources, and thermal conduction sources, and to automatically command the microclimate devices in response to the calculated occupant personal comfort based upon occupant characteristics to achieve a desired occupant personal comfort.

Abstract: A HVAC thermal conditioning system provides a macroclimate environment. An auxiliary thermal conditioning system has multiple microclimate devices in close proximity to a region of the occupant. The microclimate devices are arranged within an interior space that provides the macroclimate environment to an occupant. A controller communicates with the microclimate devices and calculates an occupant personal comfort based upon a thermal energy experienced by the occupant from thermal radiation sources, thermal convection sources, and thermal conduction sources, and to automatically command the microclimate devices in response to the calculated occupant personal comfort to achieve a desired occupant personal comfort. The automatic command adjusts and apportions the thermal conduction sources and/or thermal radiation sources to achieve the desired occupant personal comfort.

Abstract: An atmospheric water generator (AWG) may be used to extract water from ambient air. A compact screw compressor of the AWG may be used to compress refrigerant, a condenser of the AWG may be used to condense refrigerant, an expansion device, and an evaporator of the AWG may be used to transfer heat from ambient air to refrigerant, causing moisture in the air to condense. The condensed moisture may be collected in a water collection unit.

Abstract: A system and method of freeze protection for a chiller including a metering device in flow communication with a condenser, a controller in electrical communication with the metering device, wherein the controller is configured to determine whether the difference between the fluid characteristic of the first liquid and the fluid characteristic of the second liquid is greater than a freezing limit, and enter a freeze protection mode if the difference between the fluid characteristic of the first liquid and the fluid characteristic of the second liquid is greater than the freezing limit.

Abstract: Methods and systems for controlling a chiller system to achieve control stability while maintaining optimum efficiency. Particularly, methods and systems for controlling a centrifugal compressor speed and an inlet guide vane position that establishes three distinct regions in the control path: (i) during initial unloading from full load, the inlet guide vane position is kept at a fully open position while the centrifugal compressor speed is changed to achieve the desired cooling capacity; (ii) between an inflection point and a transition point, keeping the centrifugal compressor speed constant while the inlet guide vane position is changed to achieve the desired cooling capacity; and (iii) between the transition point and zero cooling capacity, changing both the inlet guide vane position and the centrifugal compressor speed to achieve the desired cooling capacity.

Abstract: A method of operating a transport refrigeration system is provided. The method includes controlling, using a controller, a first plurality of components of a refrigeration unit, wherein controlling comprises operating a prime mover and an electric generation device. The method also includes operating, using a controller, the prime mover at a selected high speed. The method further includes monitoring, using a controller, a plurality of operating parameters of the refrigeration unit, wherein at least one of the operating parameters is at least one of a voltage of the electric generation device and a speed of the prime mover. The method yet further includes comparing, using a controller, the voltage of the electric generation device to a selected voltage. The method also includes comparing, using a controller, the speed of the prime mover to a selected speed.

Abstract: Cooling units are configured to be installed in a datacenter, such as in a row configured to receive server racks. The cooling units include chilling coils configured to cool air passing across the chilling coil. The cooling units when installed supply cooled air. Units can be coupled together to expand cooling capacity, such as by forming a shared volume between adjacent units. Cooling provided through one or more coupled units can be controlled by another of the coupled units.

Abstract: Systems and methods are described for controlling fan-only cooling duration following normal air conditioning operation. Following normal AC cooling, economical fan cooling is used. The duration of the fan cooling period is adjusted based on temperature measurements made during the previous cooling cycle that ended with fan cooling. An expected temperature drop to be provided by fan cooling as well as an expected time to achieve that drop is calculated based on prior measurements. The expected values are then used improve fan cooling for subsequent cooling cycles. In some cases, fan cooling is not initiated unless: (1) a time limit has an elapsed, such that sufficient condensation is allowed to form on the evaporator coil during the first phase, and (2) indoor relative humidity is below a predetermined threshold.

Abstract: The present invention relates to air conditioners, and more particularly, to a thermal storage air conditioner in which a cold heat is produced and stored in a tank during night time for using the cold heat during day time for cooling a room. For this, the thermal storage air conditioner includes an outdoor unit having an outdoor heat exchanger for making heat exchange, and at least one compressor for compressing refrigerant, an indoor unit having a plurality of indoor heat exchangers for making heat exchange, a thermal storage unit for storing energy, the thermal storage unit having a plurality of thermal storage heat exchangers for making heat exchange, and a functional unit having a plurality of valves for selective control of refrigerant flows among the outdoor unit, the indoor unit and the thermal storage unit according to an operation mode, and a valve controller for making a unitary control of operation of the valves.

Abstract: Devices and methods for identifying an electrical device, and its state, in a network of electrical devices are disclosed. An energy monitoring device is programmed to identify an electrical device coupled to a power supply, and a state of the electrical device, from a change in successive measurements of the power supply. Algorithms for determining a load signature for an electrical device and its state are disclosed. A stored table of load signatures for states is used to identify devices, and states. Energy monitoring information is collected and presented to the user on a display, a remote display, or is transmitted over a network to a remote device such as a personal computer, personal digital assistant, an iPhone, a cell phone, voice mail, email, or text message.

Abstract: When it is assumed that a vehicle is stopped or parked after its engine was stopped and a predetermined period of time has passed, a cold wind side air mixing door, hot wind side air mixing door, cold wind door and rear cold wind side air mixing door are totally closed and a blower is operated for a predetermined period of time. Accordingly, while a cooler is being dried, drying air containing much offensive smell components, which has passed through the cooler, is discharged outside the vehicle. Therefore, it is unnecessary to provide an exclusively used air passage and an opening and closing door for opening and closing the air passage used for composing an air blowing passage to dry the cooler. By utilizing the existing equipment, air used for drying, which has passed through the cooler, containing much offensive smell components can be discharged outside the vehicle.

Abstract: A refrigeration device and method of operation, including at least two separate temperature zones, each having a set temperature range. Both zones are cooled by a separate evaporator with both of the evaporators arranged in a common coolant circuit having operational and non-operational phases. At least one temperature zone includes a fan and the temperature is measured in at least a first one of the temperature zones. The fan is operated intermittently in the operational and non-operational phases depending on a preset temperature measured in the first temperature zone. The operational and non-operational phases of the fan and the coolant circuit are operated such that the operational phases of the coolant circuit coincide at least partially with the non-operational phases of the fan.

Abstract: A refrigerator, in which air blast fans in storage chambers are controlled so as to reduce a power consumption rate, and a control method of the refrigerator. The control method includes the steps of (a) determining whether or not a plurality of air blast devices, respectively connected to a plurality of storage chambers, and a compressor are respectively in starting conditions; (b) in case that it is determined that at least two air blast devices and the compressor are in the starting conditions, turning a part of the at least two air blast devices in the starting condition and the compressor on; and (c) turning all of the air blast devices in the starting condition on after a designated time from the turning-on of the air blast device elapses.

Abstract: An apparatus and method for drying condensate from the heat exchanger of a vehicle's air conditioning system after operation in order to thwart odor buildup is provided. The apparatus and method operate regardless of whether the system's blower control circuit is positively or negatively switched. The apparatus includes relays that bypass the normal operating electrical routing to the air conditioning system's blower motor to operate the blower directly. The method comprises determining that the engine of the vehicle has been switched off and that the air conditioning system of the vehicle was in operation prior to the engine being switched off. If the conditions are met, the air conditioning system's blower is operated on a predetermined time schedule to circulate air in the air conditioning system to dry condensate therefrom. In this way, growth of odor-causing fungus and bacteria is inhibited.

Abstract: An apparatus and method for drying condensate from the heat exchanger of a vehicle's air conditioning system after operation in order to thwart odor buildup is provided. The apparatus and method operate regardless of whether the system's blower control circuit is positively or negatively switched. The apparatus includes relays that bypass the normal operating electrical routing to the air conditioning system's blower motor to operate the blower directly. The method comprises determining that the engine of the vehicle has been switched off and that the air conditioning system of the vehicle was in operation prior to the engine being switched off. If the conditions are met, the air conditioning system's blower is operated on a predetermined time schedule to circulate air in the air conditioning system to dry condensate therefrom. In this way, growth of odor-causing fungus and bacteria is inhibited.

Abstract: The present invention balances power consumption reduction and a cooling in a vehicle air-conditioning system having a compressor selectively driven by a vehicle engine or a motor while the compressor is driven by the motor. At least one of a capacity of a blower and a capacity of a compressor arranged in a refrigeration cycle R while the compressor being driven by a motor is reduced in comparison to the capacity of the blower and the capacity of the compressor while the compressor being driven by a vehicle engine. Furthermore, while a cooling heat load of an evaporator is greater than a predetermined value, the capacity of the compressor is first reduced prior to reducing the capacity of the blower.

Abstract: The refrigerator includes a plurality of rooms separated by partition walls; an air blower to send cooling air cooled by an evaporator into a refrigerator box; a fan motor 65 to drive the air blower; a damper device 50 to adjust an amount of the cooling air of at least one room, of amounts of cooling air flowing into the rooms; and control means 2 and 93 for driving the fan motor 65 without fail just before the baffle of the damper device 50 is opened. The temperature at which the bimetal thermo-switch 2 moves from one terminal 2a to the other terminal 2b, is set lower than the temperature at which the bimetal thermo-switch 93 moves from the closing terminal 93b side to the opening terminal 93a side, and the bimetal thermo-switch 2 is made to move to the other terminal 2b side before the baffle moves from the close-status to the open-status.

Abstract: A refrigerator includes a compressor, a condenser for liquefying a refrigerant discharged from the compressor, a plurality of refrigerant passages disposed at a downstream side of the condenser, a switching valve for switching a flow of refrigerant to one of the refrigerant passages so that the refrigerant liquefied by the condenser flows through the selected refrigerant passage, the switching valve including a valve body, and a controller for controlling the switching valve so that the switching valve performs a switching operation upon expiration of a period of time sufficient for an interior of the valve body of the switching valve to be filled with the liquid refrigerant after start of the compressor.

Abstract: An integrated heat pump and electrical heat control (12) has thermostat signal inputs (O, W1, W2, G, Y) along with a defrost sensor input (DF_IN). The defrost sensor (22) is located in an outdoor unit (4) which also includes a compressor contactor (CC), condenser fan (16) and reversing valve (18) relays (K4, K3, K2) controlled by micro-controller (U1). The normally closed condenser fan relay (K3) is energized through the defrost sensor forming a hardware lock-out in which the defrost sensor contacts must be closed for relay (K3) to be actuated de-energizing the condenser fan. The compressor contactor (CC) is energized through a low pressure switch (24) and high pressure switch (26) forming another hardware interlock. The evaporator fan is energized by relay (K1) controlled by micro-controller (U1) and matched to the compressor for improved efficiency and comfort.

Abstract: Disclosed is an apparatus for controlling a cooling unit, for instance, for an automatic vending machine. A condenser fan motor and an evaporator fan motor are of DC motors having high energy efficiency. The condenser fan motor is started by a gradually increasing Dc voltage, and the condenser fan motor and the evaporator fan motor are sequentially starred with a predetermined time interval.

Abstract: A mode of operation of an air-conditioning installation of a compression cycle type helicopter cabin or cockpit air-conditioning installation is characterized in that it includes a start-up sequence controlled by an inverter controlling the motor-compressor associated with a condenser equipped with a fan and during which the fan of the condenser is first powered up, after which the motor-compressor is powered up to start it at a low speed, after which the motor-compressor is operated under its normal conditions as a function of the cooling requirements of the installation. Other features concern the mode of powering the motor-compressor in accordance with various atmospheric and operating conditions.

Abstract: A low temperature storage cabinet having a freezing cycle system composed of a compressor, a condenser, a throttle and an evaporator, a cabinet temperature sensor for detecting an inside temperature of the cabinet, and an electric fan provided in the cabinet for circulating cooled air in the interior of the cabinet, wherein the compressor in the freezing cycle system is activated in response to rise of the inside temperature of the cabinet and deactivated in response to a fall in the inside temperature of the cabinet, and wherein the rate of operation of the electric fan is decreased in accordance with a decrease of temperature or pressure of refrigerant in the freezing cycle system during deactivation of the compressor to thereby reduce consumption of the electric power.

Abstract: A method of drying condensate from the heat exchanger of a vehicle's air conditioning system after operation in order to thwart odor buildup is provided. The method comprises first determining that the engine of the vehicle has been switched off and that the air conditioning system of the vehicle was in operation prior to the engine being switched off. If these two conditions are met, the blower of the vehicle's air conditioning system is operated on a predetermined time schedule to draw air through the heat exchanger and through the air conditioning duct work to dry condensate from the heat exchanger and from interior surfaces of the duct work. In this way, the growth of fungus and bacteria that cause odor is thwarted.

Abstract: A refrigeration controller is provided which thermostatically controls a refrigerated compartment temperature. A heated evaporator is provided within a certain wattage range to accelerate defrosting. The controller maintains the compartment temperature within a certain operating range; if the compartment temperature rises above a certain preselected maximum temperature, the controller activates the compressor and a blower to circulate air over the evaporator to reduce the temperature of the compartment. The controller provides a defrost loop which is periodically activated which controls the compressor, evaporator and heater cycle during defrost. If, during defrost, the evaporator reaches a maximum temperature, or if the food compartment temperature rises above a certain maximum, the heater is deactivated. An evaporator precool loop is provided which activates the compressor without activating the blower, thereby cooling the evaporator before hot air is allowed to circulate in the compartment.

Abstract: The invention is an improved timer circuit for operating a heating or air conditioning unit which utilizes a single time delay generating circuit for delaying operation of both a compressor and a unit fan under certain operating conditions. A logic circuit for operating a fan relay is made responsive to the thermostat output and a time delay generating circuit output so that the fan relay is de-energized only in the case that the compressor has been turned off for at least the duration of a time delay generator timing period, and is in a state commensurate with a satisfactory building temperature. When the timer circuit is used in large-scale heating or air conditioning systems, the timing period of each timing circuit can be adjusted to a different duration so that a voltage lag problem on start up is avoided.

Abstract: A method of operating a heat pump or air conditioner system is provided. The air conditioner comprises a compressor, a condenser, an expansion device, a cooling coil and an air mover (blower). According to the preferred embodiment, the air mover (blower) is activated at a time after the compressor has been activated to pre-cool the cooling coil and allow for more efficient and effective moisture removal. Also, deactivation of the air handler is delayed for some time after the compressor is deactivated to allow for utilization for the residual cooling ability of the cooling coil due to the presence of cold refrigerant in the cooling coil when the compressor is deactivated.

Abstract: An attachment unit (28) to an existing central air conditioning thermostat controller (24) like the ones found in most homes and offices; which provides two independent modes of saving energy, first by turning on a light to indicate when to change the filter and secondly by extending the fan operation for a few minutes without disruption. Uniquely conceived, smaller than the typical thermostat controller, automatic, maintenance free, no batteries or auxiliary power of any kind. Has one button (32) to reset the light (30) after changing the filter and one switch (34) to select the optional extended fan operation.

Abstract: An apparatus for driving a fan as part of a refrigerator is disclosed. The refrigerator has a compartment, a compressor, an evaporator and a condenser. A temperature sensor is positioned in association with the compartment and outputs a sensed temperature signal as a function of the temperature in the compartment. The apparatus includes a reference circuit which provides a desired temperature signal representative of a desired temperature. A comparator compares the desired temperature signal and the sensed temperature signal and generates a cool signal when the compartment temperature is above the desired temperature. A timer times out an elapsed period of time commencing when the cool signal is generated. A motor includes a rotatable assembly in driving relation to the fan. A control circuit controls operation of the motor as a function of the sensed temperature signal and the elapsed period. Related apparatus and methods are also disclosed.

Abstract: System and method for air conditioning of vehicles to prevent inside window fogging, the vehicle having a compartment with a windscreen heated by an air flow of controlled temperature, and the system including an evaporator, a blower or fan for drawing air over the evaporator and ducting for air distribution. In order to prevent misting of the inside of the windscreen after the vehicle has been parked with the engine shut off, the fan is deactivated and preferably also the fresh air intake is closed for a time period after switching on the air conditioning system.

Abstract: This invention has as its object to provide a method and apparatus for controlling a vehicle air conditioner, which can obtain a combination of an outlet air flow rate V.sub.a and an outlet air temperature T.sub.o, which is desirable for comfort of a passenger, under a condition of air-conditioning control based on a heat balance equation. In order to achieve this object, this invention provides a method of controlling a vehicle air conditioner, including the first step of obtaining, from a heat balance equation, a plurality of combinations of the outlet air flow rates V.sub.a and the outlet air temperatures T.sub.o necessary for maintaining the passenger room temperature to be a predetermined target temperature, the second step of calculating comfort indices each representing the comfort level of a passenger on the basis of state amounts of factors which influence comfort felt by the passenger in the passenger room, and the plurality of combinations of the outlet air flow rates V.sub.

Abstract: An apparatus controls an appliance, the appliance including a compressor, a fan, and a heater. The apparatus includes a first switch for selectively coupling a first terminal with one of a second terminal and a third terminal in response to a first control signal. The first terminal is coupled with an energy source and the third terminal is coupled with the compressor. The apparatus further includes a second switch for selectively coupling the second terminal with the heater and the third terminal with the fan in response to a second control signal. The apparatus still further includes a control circuit coupled with the first switch and the second switch for generating the first control signal and the second control signal. A relay drive circuit couples relay coils in series to control the first switch, the second switch, and the third switch. A bypass switch allows a single current to selectively energize one or both relay coils.

Abstract: A method of eliminating odor in a heat pump system of a vehicle includes the steps of detecting removal of the vehicle passengers and ignition key after use of the cooling mode or air conditioning of the passenger compartment heat exchanger, operating the blower, reversing the flow of refrigerant in the heat pump to place the passenger compartment heat exchanger in heating mode to remove latent moisture to eliminate odor therefrom.

Abstract: A controller for controlling the capacity of a centrifugal chiller compressor. The compressor is driven by an electric motor and has variable inlet guide vanes that control the flow of refrigerant to the compressor. The controller establishes a dimensionless plot of possible points of compressor operation relating the pressure coefficient and the capacity coefficient of the compressor. The current operating point of the centrifugal compressor is located on the plot and a dynamic surge boundary control curve is positioned proximate a region of actual surge. Control is exercised responsive to the variations of the region of actual surge and the surge boundary control curve for controlling compressor capacity by varying the opening of the inlet guide vanes and varying the speed of the compressor to move the operating point of the compressor proximate the surge boundary control curve.

Abstract: A cooling system (10) with a control temperature sensor (24) for sensing the temperature of a coolant coil (14) for control of a coolant coil fan (18) in cooperation with ambient temperature sensed by a thermostat (30) to obtain optimum utilization of residual cooling power of the coolant coil (14) after the condenser (28) has been deactivated and to protect against overcooling and consequent icing of the coolant coil (14) in the event of inadvertent failure of the thermostat (30) to turn off the condenser(28).

Abstract: A solid state control circuit operative for connection to existing low-voltage thermostat terminals of a central, forced-air, air-conditioning system having a compressor and an indoor blower (referred to herein as a "fan") and gas-fired or electrical heating elements. Automatic means is provided for starting the blower simultaneously when the compressor or electric heating elements are turned on, but the blower continues to run by a timer for a predetermined timed period after the compressor is stopped, during cooling and heat pump heating, and is stopped simultaneously when the heating elements are turned off during electric heating. The control circuit is automatically inoperative with gas heat, since the blower in gas heating systems is controlled by a separate plenum thermostat which introduces start and stop delays independent of the room thermostat.

Abstract: A heat pump diagnostic and control system for controlling indoor coil freeze-up when in the cooling mode is provided. A low indoor coil temperature is sensed, the indoor fan speed is increased in steps up to a maximum to thaw the frost on the indoor coil. If this is not sufficient, the compressor speed is then reduced in steps until it is turned off and if necessary, it is held off until such time as the temperature sensor indicates thawing of the indoor coil of the heat exchanger. Diagnostic flow chart and control circuitry for accomplishing this control are disclosed.

Abstract: Disclosed is an air conditioner for use in an automotive vehicle. The air conditioner includes a timer circuit for deciding whether or not a given period of time has elapsed after an engine of the automotive vehicle has been started, an air quantity controller for limiting the amount of air to be introduced into a passenger compartment for a given period of time after an air cooling operation has been started, a compressor controller for prohibiting the operation of a compressor of the air conditioner for the given period of time to be decided by the timer circuit, a temperature sensor for detecting the temperature of the passenger compartment, and a switch portion for starting the compressor. The timer circuit, the air quantity controller, the compressor controller, and the switch portion are all provided in an air conditioner control unit.

Abstract: An improved method and apparatus or control system for electronically sequencing the main components in central air-conditioning and heat pump systems normally comprising an outside fan motor, a compressor motor, and an inside blower motor, is disclosed. When comfort production or conditioned air is needed, the outside fan motor is initially turned on. After a predetermined programmable period of time, the compressor is turned on, and then, after another predetermined programmable period of time, the inside blower is turned on to deliver production air to the space or area being serviced. At the end of the comfort cycle, the outside and compressor motors are turned off while the inside blower motor continues to run for a third predetermined programmable period of time.

Abstract: An accessory device for conventional refrigeration systems that include an auxiliary compressor of lower capacity piped in parallel with the compressor of the conventional system. The auxiliary compressor cuts in after a certain temperature is reached and automatically the speed of the fan is decreased to compensate for the lower capacity of the system. Time delays are incorporated to each of the compressors to allow the high and low pressure ports to equalize.

Abstract: A control circuit for an auger type ice maker using a relay which is responsive to a predetermined level of an ice making water in a tank and to of a predetermined level of stored ice, and a timer circuit responsive to the commencement of the ice making cycle which corresponds to the detection of the water level and the completion of the ice making cycle which corresponds to the detection of the ice level, both by the relay. This timer circuit is arranged so that during the starting operation it starts to drive the auger motor at the beginning of the ice making cycle and then after a first predetermined time starts to drive the compressor, and during the stopping operation, it stops the compressor after a second predetermined time after the detection of the completion of the ice making cycle and then after a third predetermined time stops the auger motor. Should a short interruption of the supply of water occur, the timer circuit can ignore it because of its delay time.

Abstract: A vapor compression distilling device (10) includes a first chamber (30) adapted to contain liquid (32) to be distilled. A compressor (70) is interconnected to the first chamber (30) for withdrawing vapor from the liquid (32) in the first chamber (30). The compressor (70) also functions to compress the vapor. A second chamber (12) is adapted to receive the compressed vapor from the compressor (70) such that the compressed vapor is condensed in the second chamber (12) into a liquid condensate. A device (16) is disposed in the second chamber (12) for boiling, concentrating and circulating the liquid (32) to be distilled. The device (16) is provided with circulating flow connections (18, 36) to the first chamber (30) and extends into the second chamber (12), such that the exterior of the device (16) is exposed to the compressed vapor generated by the compressor (70).

Abstract: A control circuit for cycling the evaporator fans on and off independently of the operation of the compressor of the refrigeration system is described. The evaporator fan is cycled on with the compressor and continues to run during the entire compressor ON cycle. A first timer causes the evaporator fan to run for an additional delay period following the cycling OFF of the compressor and the fans continue to blow air over the evaporator coil until the temperature of the evaporator coil is sufficiently above the freezing point of water (32.degree. F., 0.degree. C.). The fans are then cycled OFF. A second cycling timer is provided to intermittently cycle the evaporator fans on and off for predetermined short intervals following the above-described delay period, and during the time when the compressor is OFF. A third timer is provided to preclude freezing of the vended products and/or the evaporator coil when a vending machine is disposed in a below-freezing environment.

Abstract: Temperature and humidity electrical/electronic control circuits and apparatus to maintain a room at a constant temperature and humidity. The control system is adapted to an environmental condition controller for year-around cooling utilizing a liquid recirculating to an outside coil for free cooling or free reheat dehumidification. The controls provide a sequencing function to actuate one or more temperature and/or humidity conditioners in response to the degree and percentage of change. The circuit provides a ramp function signal for proportional control over an initial temperature range of free cooling and step controls over other predetermined temperature ranges. The circuit comprises a high fidelity ramp generator linearly responsive to the degree of temperature change up to a predetermined set point. A dehumidification signal is developed and fed to the same ramp generator to carry out air cooling to remove moisture.

Abstract: The control system of the invention regulates a centrifugal compressor having inlet guide vanes adjustable as one means for varying the compressor capacity. A variable speed motor is connected to drive the compressor, and provides another means for regulating the compressor capacity. The control system regulates the motor speed alone over one portion of the load variation curve, and regulates the motor speed jointly with the inlet guide vane opening over another portion of the load variation curve, to achieve the most energy-efficient operating condition while avoiding the surge condition. This optimum control path is realized by utilizing a signal which is a measure of the compressor head value. Compressor surge or instability is avoided by deriving a critical Mach number (speed indication) for any given operating condition, as a function of the compressor head and vane position, and preventing the motor speed from going below that Mach number under the specific operating conditions.

Abstract: The present invention relates to a refrigeration system of the type having an air cooled condenser which includes the further capability of producing a heated liquid in a liquid cooled or, "heat recovery" condenser. The system includes compressor means for compressing a vaporized refrigerant, air cooled condenser means having fan means for forcing air in heat exchange relationship therewith, liquid cooled condenser means for producing a heated liquid, and evaporator means for expanding and vaporizing condensed refrigerant in heat exchange relationship with a refrigeration load. Control means are provided for the system and include first means for sensing the demand for heated liquid from the liquid cooled condenser, and second means responsive to the first means for reducing the capacity of the fan means in response to increased demand for heated liquid.

Abstract: A low temperature storage cabinet having a freezing cycle system composed of a compressor, a condenser, a throttle and an evaporator, a cabinet temperature sensor for detecting an inside temperature of the cabinet, and an electric fan provided in the cabinet for circulating cooled air in the interior of the cabinet, wherein the compressor in the freezing cycle system is activated in response to rise of the inside temperature of the cabinet and deactivated in response to a fall in the inside temperature of the cabinet, and wherein the rate of operation of the electric fan is decreased in accordance with a decrease of temperature or pressure of refrigerant in the freezing cycle system during deactivation of the compressor to thereby reduce consumption of the electric power.