Abstract: A sound level control system for a heating, ventilation, and air conditioning (HVAC) system is provided. The sound level control system comprises an outdoor unit with a compressor, an outdoor fan, and an outdoor controller and a communication device located at a predefined distance from the outdoor unit. The communication device measures sound levels in response to operating the outdoor unit. The outdoor controller is configured to receive a first noise level limit for a predefined time period, receive an instruction related to selective control of the outdoor unit, selectively control both of the compressor to rotate at a first compressor speed and the outdoor fan to rotate at a first fan speed based on the noise level limit for the predefined time period, and receive information related to whether a sound pressure level at a predefined location exceeds the first noise level limit for the predefined time period.

Abstract: The present invention provides a cold-storage instantaneous heat pump water heater (HPWH). The HPWH includes a cold-water tank, a main evaporator, a compressor, and a hot water heat exchanger. In the present invention, heat of a working medium in the cold-water tank is absorbed by the main evaporator, and bathing water is rapidly heated by the hot water heat exchanger (condenser of the heat pump), thereby realizing instant heating with small input electrical power. Cold-water tank replaces the hot water tank of conventional HPWH avoiding energy loss during hot water storage. The working medium in the cold-water tank absorbs heat from the environment, to further improve energy utilization. In addition, there are three energy recovery evaporators to recover the waste heat of bathing.

Abstract: A method is provided for controlling an HVAC system. The method includes receiving zone priority levels and zone temperature setpoints, where at least one of the zones haves a higher priority level than others of the zones, receiving an indication of zone ambient temperature values, determining requested zone capacity values to maintain the zone ambient temperature values within a threshold deviation of respective ones of the zone temperature setpoints, determining target zone capacity values from the requested zone capacity values and zone size values, and from the zone priority levels where the target zone capacity values may be responsive to a total of the requested zone capacity values that is less than a minimum capacity or greater than a maximum capacity of the HVAC system, and causing the HVAC system to provide the conditioned air to the zones according to respective ones of the target zone capacity values.

Abstract: An HVAC system with an integrated source of outdoor air is provided. In one embodiment, an HVAC system includes an outdoor unit, having a compressor and a heat exchanger, and a ventilation unit to receive and provide outdoor air to a structure. The ventilation unit has a blower, a dehumidifying coil, and a reheat coil installed in a housing. The HVAC system also includes a first electronic expansion valve coupled outside the housing of the ventilation unit to control refrigerant flow into the dehumidifying coil and a second electronic expansion valve coupled outside the housing of the ventilation unit to control refrigerant flow into the reheat coil. An electronic expansion valve controller is connected to control operation of the first electronic expansion valve and the second electronic expansion valve. Additional systems, devices, and methods are also disclosed.

Abstract: Air conditioner units and methods of operating the same are provided. A method of operating an air conditioner unit includes determining a fan speed as a function of a compressor speed of a variable speed compressor of the air conditioner unit. The method also includes activating a variable speed fan of the air conditioner unit at the fan speed. An air conditioner unit may include a controller, and the controller may be configured for performing the method.

Abstract: A method to continuously monitor for tube leakage in a shell and tube thermosiphon reboiler for heating feedstock in a fractionating column includes: determining the column is in service by continuously monitoring an input flow of the feedstock into the column; determining the reboiler is inactive by continuously monitoring an output valve of tube-side heating fluid from the reboiler; determining the reboiler is losing the heating fluid by continuously monitoring an output flow of the heating fluid from the reboiler; determining the reboiler is heat exchanging by continuously monitoring a temperature difference between input and output flows of shell-side bottoms fluid with the column; and determining the tube leakage in the reboiler is taking place when the column is determined to be in service, the reboiler is determined to be inactive, the reboiler is determined to be losing the heating fluid, and the reboiler is determined to be heat exchanging.

Abstract: A cryocooler includes a cold head, a plurality of compressor main bodies that are connected to the cold head in parallel, a plurality of state detection sensors that are provided to correspond to the plurality of compressor main bodies respectively and each detect a state of a corresponding compressor main body to output a state detection signal, and a compressor control unit that is configured to, in a case where the state detection signal from any one state detection sensor of the plurality of state detection sensors indicates that the corresponding compressor main body is stopped, stop also the other compressor main bodies.

Abstract: An active dual roll shutter apparatus for a vehicle has two lead screws rotated by power from a single motor. First and second roll screens are simultaneously operated upward and downward in opposite directions along the two lead screws to open a flow path when the lead screws rotate, thereby improving sealability of the flow path and aerodynamic performance of the vehicle.

Abstract: A cooling system includes a first cooler, a second cooler, a fan positioned to drive air through the first cooler and the second cooler, and a baffle system. The baffle system includes a baffle and an actuator. The baffle is positioned to facilitate selectively restricting airflow through at least a portion of the first cooler. The actuator is positioned to facilitate reconfiguring the baffle between (i) a first orientation where the baffle does not restrict the airflow through the portion of the first cooler and (ii) a second orientation where the baffle restricts the airflow through the portion of the first cooler, thereby diverting additional airflow through the second cooler.

Abstract: A thermal recovery device for recovering waste heat from a sink having a bottom plate, the bottom plate having a top surface and a bottom surface, wherein the bottom plate being a thermal conductor, the thermal recovery device including: a tube including an inlet and an outlet, the tube thermally connected to the bottom surface, wherein thermal communication exists between the top surface and a fluid in the tube, a demand for the fluid causes the fluid to flow through the tube and heat transfer to the fluid which raises the temperature of the fluid prior to entering a heater and subsequently arriving at the top surface of the bottom plate of the sink from which the heat is transferred, reducing the heating load of the heater due to the demand of the fluid.

Abstract: A communication control system for a number of gas compressors where one gas compressor is set as a master gas compressor that controls communication with N slave gas compressors. A cycle of communication with the N slave compressors in N communication sets is defined as a total compressor number communication cycle. In first to Nth communication sets, a first response request is transmitted to each of the first to Nth gas compressors. When a response is received from one of the gas compressors, the system determines that connection with the one gas compressor has succeeded. When no response is received, the system determines that connection has failed. In following communication cycles, a second response request is transmitted to the slave compressors with which communication has succeeded. The first response request is then transmitted to the slave compressors with which the communication connection has failed using a different timing sequence.

Abstract: Custom cooling strategies may be implemented for different regions in computers, servers, and other information handling systems. Chassis architecture may have multiple cooling fans, with each fan cooling a different region via dedicated duct work. A user or administrator may thus implement different cooling strategies for internal components, based on different thermal curves defined for each different region.

Abstract: A water dispensing system includes a faucet, a sink basin mounted beneath the faucet downstream therefrom, a first storage tank mounted below the sink basin to store a first liquid volume, a second storage tank mounted below the sink basin to store a second liquid volume, and a vapor compression system including a compressor, an evaporator in fluid communication with the compressor, the evaporator being connected to the first storage tank in conductive thermal communication, a condenser in fluid communication with the compressor, the condenser being connected to the second storage tank in conductive thermal communication, and an expansion device in fluid communication with the compressor.

Abstract: An equipment unit state controlling method and device, and an equipment unit. After receiving control data transmitted from a state controller, a unit controller detects whether the unit controller communicates with a display panel controller, in which the state controller transmits the control data to the unit controller and the display panel controller simultaneously. If the unit controller communicates with the display panel controller, the unit controller performs an operation on the equipment unit corresponding to instruction information transmitted from the display panel controller, and if the unit controller does not communicate with the display panel controller, the unit controller parses the control data by itself to obtain the parsing result and performs the operation on the equipment unit corresponding to the parsing result.

Abstract: Systems, apparatus and methods for operating a chiller plant while minimizing or eliminating the occurrence of centrifugal compressor surge. Taking into account chiller design specifications and current operating conditions, a compressor lift point at which surge is predicted to occur is established. Minima and maxima for various chiller setpoints that avoid or eliminate the occurrence of compressor surge are imposed on setpoints provided by a conventional optimizing chiller controller. The chiller system is operated in accordance with the resultant anti-surge setpoints. Coolant tower flow is modulated to enable the compressor to operate at near-surge conditions while preventing the onset of actual surge.

Abstract: The present disclosure relates to a heating, ventilation, and air conditioning (HVAC) unit having a vapor compression circuit including a compressor and a heat exchanger. The HVAC unit includes a controller configured to provide a first signal to control the compressor, and provide a second signal to control a variable speed fan associated with the heat exchanger based on a target speed. The HVAC unit further includes a pressure activated device coupled between the controller and the compressor, wherein the pressure activated device is configured to temporarily block the first signal from the controller while a refrigerant pressure within the vapor compression circuit is greater than a threshold value. In response to determining that the pressure activated device has blocked the first signal for at least a threshold time period, the controller is configured to both deactivate the first signal and provide the second signal for an equilibration time.

Abstract: Various embodiments include a system for controlling air temperature. The system can include a potable water piping system, a cooling system, and a heating system. The potable water piping system can include potable water supply piping and potable water return piping. The cooling system can be coupled to the potable water piping system. The cooling system can include a water-refrigerant heat exchanger; an air-refrigerant coil; a compressor coupled between the water-refrigerant heat exchanger and the air-refrigerant coil; and an expansion valve coupled between the water-refrigerant heat exchanger and the air-refrigerant coil. The heating system can be coupled to the potable water piping system. The heating system can include a hot water coil. The water-refrigerant heat exchanger can be coupled to the potable water supply piping and the potable water return piping. The hot water coil can be coupled to the potable water supply piping and the potable water return piping.

Abstract: A heat pump apparatus includes a use-side heat exchanger that causes heat exchange to be performed between a heat medium flowing from a heat-storage heat exchanger and a heat usage medium, and a flow-passage switching device that switches a flow passage for the heat medium to a first flow passage that circulates through a heat-reception-side heat exchanger and the heat-storage heat exchanger without extends through the use-side heat exchanger or a second flow passage that circulates through the heat-reception-side heat exchanger and the heat-storage heat exchanger via the use-side heat exchanger. Even when the temperature of the heat storage medium rises, heat received from a heat source can be stored in the heat storage medium by a heat pump, while a decrease of the efficiency of the heat pump can be reduced.

Abstract: A vapor compression system includes a compressor, a first heat exchanger, an expansion valve and a second heat exchanger arranged serial refrigerant flow path; a first fan configured to direct air over the first heat exchanger; a controller coupled to the first fan and the compressor, the controller configured to: set a compressor discharge superheat limit; determine a compressor discharge superheat; compare the compressor discharge superheat to the compressor discharge superheat limit; and when the compressor discharge superheat is less than the compressor discharge superheat limit, the controller reducing at least one of a compressor speed and a first fan speed.

Abstract: A device under test cooling system has a refrigerant line and a fluid line extending through a plurality of successively arranged heat exchangers. A digital scroll compressor has an intake for providing the refrigerant mixture to the compressor and a discharge connecting the compressor to the refrigerant line to provide the refrigerant mixture to the heat exchangers. The compressor includes a plurality of scroll elements between the intake and the discharge for compressing the refrigerant mixture. The compressor includes a valve configured to separate the scroll elements when in an open position to allow refrigerant to flow freely between the intake and the discharge. When the valve is in a closed position, the scroll elements compress the refrigerant. A controller is configured to switch the valve between an open and closed position based on a set duty cycle.

Abstract: An apparatus for optimizing an efficiency of a refrigeration system, comprising means for measuring a refrigeration efficiency of an operating refrigeration system; means for altering a process variable of the refrigeration system during efficiency measurement; and a processor for calculating a process variable level which achieves an optimum efficiency. The process variables may include refrigerant charge and refrigerant oil concentration in evaporator.

Abstract: An air conditioning apparatus uses R32 as a refrigerant, and includes a compressor, a condenser, an expansion mechanism, an evaporator, an intermediate injection channel, a suction injection channel, a switching mechanism, a branch flow channel, first and second injection opening adjustable valves, an injection heat exchanger, a refrigerant storage tank, a bypass channel, and a control part. The switching mechanism switches between an intermediate injection condition in which refrigerant flows in the intermediate injection channel, and a suction injection condition in which refrigerant flows in the suction injection channel. The branch flow channel branches from a main refrigerant channel which joins the condenser and the evaporator, and guides the refrigerant to the intermediate injection channel and the suction injection channel.

Abstract: A refrigeration system for a temperature-controlled storage device includes a refrigeration circuit, a cooling circuit, and a controller. The refrigeration circuit includes a compressor driven by a brushless DC motor operable at multiple different speeds, a first heat exchanger, an expansion device, and a cooling unit in fluid communication via a first working fluid. The cooling circuit includes a pump and a second heat exchanger in fluid communication with the first heat exchanger via a second working fluid such that the first heat exchanger is liquid-cooled by the second working fluid. The controller operates the brushless DC motor at multiple different speeds to accommodate multiple different thermal loads experienced by the refrigeration system. Each of the speeds corresponds to a different thermal load. The controller modulates the speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled device.

Abstract: An air-conditioning apparatus includes a heat medium system configured to control a flow rate of the heat medium supplied to the heat source unit side heat exchanger that exchanges heat between refrigerant and the heat medium, the heat medium system having at least one system of a heat medium conveyor, a heat medium flow rate adjuster, and a heat medium flow rate control device. In the air-conditioning apparatus, the operation of each of use-side heat exchangers is changed to a cooling operation or a heating operation in accordance with a control command, and a cooling and heating concurrent operation is performed. The refrigerant is caused to flow through the heat source unit side heat exchanger in accordance with the ratio of the total cooling capacity of the use-side heat exchangers to the total heating capacity of the use-side heat exchangers.

Abstract: The HVAC condition based maintenance system and method provides for a system to reduce operating costs by replacing existing time based scheduled maintenance with an on-condition based maintenance system and method for continuous monitoring and acquiring condition based data from an operating HVAC system, transmitting data to a remote server for storage, analysis and trending, recognizing operational performance reductions based on the comparison of current trending to historical data, and for triggering notification of failures and corrective action based on routine, impending and immediate problem recognition. Additionally, the acquired data is used to derive actual heat load characteristic of the building, identify HVAC system deficiencies, building deficiencies and installation issues and load imbalance of multi-unit systems providing direction for system improvements.

Abstract: A method for regulating a discharge fan and a coil of a heating, ventilation, and air conditioning (“HVAC”) system includes maintaining a discharge fan capacity at a low fan capacity setting and varying a coil discharge air temperature between a low discharge air temperature limit and a high discharge air temperature limit. The method also includes, when the coil discharge air temperature reaches the low discharge air temperature limit, varying a fan speed of the variable speed discharge fan between a low fan speed setting and a high fan speed setting so as to maintain a space temperature at a space temperature setpoint set for a space, while maintaining the coil discharge air temperature at the low discharge air temperature limit.

Abstract: A system includes a variable-capacity compressor operable at a first capacity and at a second capacity that is higher than the first capacity and an outdoor-air-temperature sensor. A control module receives a demand signal from a thermostat and operates the variable-capacity compressor in a first mode when communication with the outdoor-air-temperature sensor has not been interrupted and in a fault mode when communication with the outdoor-air-temperature sensor has been interrupted. In the first mode, the control module switches the variable-capacity compressor between the first capacity and the second capacity based on the demand signal and the outdoor-air-temperature data. In the fault mode, the control module operates the variable-capacity compressor by operating the variable-capacity compressor at at least one of the first capacity and the second capacity based on the demand signal.

Abstract: A control system for a refrigeration system with dual evaporators is provided. In one embodiment, a control system for a dual evaporator refrigeration system is provided where the evaporators are operated simultaneously to provide for improved temperature and humidity control in a refrigerator appliance. In another embodiment, the control system can also use a linear model that is designed to minimize or remove excess enthalpy from one or more compartments and/or features of the appliance. The control system can also be configured with at least one variable speed compressor that is operated at a speed that will remove excess enthalpy within a desired time period while also operating at an optimized speed for energy efficiency.

Abstract: Systems and methods for low ambient air temperature cooling in air-source based heat pump systems wherein an outdoor heat pump unit includes a discharge hood positionable over its fan. The hood including a damper that is openable and closeable as a function of outside temperature. The outdoor unit may also include wind deflectors positioned over the coil openings of the disclosure. During cooling operations below a low outside air threshold temperature, e.g., below 23° F., the damper assembly partially closes to reduce airflow across the condenser coil of the outdoor unit to a level below that which is possible at minimum fan speed. As the outdoor temperature continues to drop, the damper assembly continues to close to further reduce airflow.

Abstract: Methods and systems for systems and methods for optimizing usage of a free cooling subsystem are provided. The method includes collecting micro-climate data from one or more sensors surrounding a facility. The method also includes analyzing the micro-climate data and making a determination to operate a free cooling subsystem or a paid cooling subsystem based on the analysis of the micro-climate data.

Abstract: A system and method for liquid-liquid free-cooling that may include a modular coolant distribution unit (CDU) is provided. CDUs can incorporate integral free-cooling or bolt on free-cooling switch modules. The free-cooling flow can be either direct or indirect. Units can interface with each other to provide scalable cooling for computer data centers. Embodiments of the system can integrate with electronics rack passive rear door liquid heat exchangers.

Abstract: An air conditioner may include an indoor device and an outdoor device. The outdoor device may include a plurality of compressors, a plurality of bypass tubes respectively connected to the plurality of compressors, and a plurality of bypass valves respectively provided to the bypass tubes. When at least one of the plurality of compressors is stopped during operation of the air conditioner and the plurality of compressors, a bypass valve corresponding to the stopped compressor may be opened to equalize an internal pressure of the stopped compressor to facilitate a re-start of operation of the stopped compressor without adversely affecting overall performance of the air conditioner.

Abstract: The present invention relates to a diagnostic method for a clothes treating apparatus, and according to an aspect of the present disclosure, there is provided a diagnostic method of a clothes treating apparatus having a compressor, a condenser, an expansion apparatus, and an evaporator for cooling air being discharged from a drum by the evaporator a heat pump, and the method may include activating the compressor; measuring a property (P1) of the refrigerant that has passed through the compressor; re-measuring a property (P2) of the refrigerant that has passed through the compressor after a predetermined period of time has passed; checking whether or not a value F that is defined as P2?P1 is equal to or greater than a predetermined value; suspending the operation of the compressor and repeating the foregoing processes when the value F is less than the predetermined value; and determining that a failure has occurred in the clothes treating apparatus when the execution number of the processes is equal to or grea

Abstract: A condenser assembly through which a refrigerant is circulated to transfer heat from the refrigerant to ambient air in which the condenser assembly is at least partially disposed. The condenser assembly includes a compressor, a crankcase heater energizable via a crankcase heater control circuit, a condenser, a condenser fan, and an electronically commutated condenser fan motor. The condenser assembly also includes an ambient temperature sensor for sensing at least one temperature of the ambient air, to provide a sensed temperature. The condenser assembly includes a condenser switch subassembly configured to control energization of the crankcase heater and the condenser fan motor. The condenser switch subassembly is controlled by the ambient temperature sensor. The condenser fan motor is controlled by a condenser fan controller that applies a first voltage or a second voltage to the condenser fan motor depending on whether a third conductor attached to the motor is energized.

Abstract: A modular heat exchange system having a refrigerant system for cycling a refrigerant through a compressor, a condenser, an expansion valve, and an evaporator, a heat source circulation system which circulates a heat exchange fluid between a heat source and the evaporator, a heat sink circulation system which circulates a heat absorption fluid between a heat sink and the condenser, a fluid management system having temperature gauges for respectively reading core temperatures of the heat source and the heat sink, and a thermal energy source from which thermal energy is transferred to the heat exchange fluid when the core temperature of the heat source falls below a threshold temperature while the core temperature of the heat sink is maintained at a constant temperature.

Abstract: An object of the present invention is to keep an appropriate high pressure side pressure in a refrigerant circuit while reducing noises of an operation of a blower in a refrigerating apparatus which obtains a critical pressure on a high pressure side. The refrigerating apparatus in which the refrigerant circuit is constituted of a compressor, a gas cooler, a reducing element and an evaporator to obtain a supercritical pressure on the high pressure side includes a blower which air-cools the gas cooler and a control device which controls this blower. This control device controls a revolution speed of the blower based on an outdoor temperature and an evaporation temperature of a refrigerant in the evaporator.

Abstract: An air conditioner and a method of operating an air conditioner are provided. The air conditioner may include at least one indoor device, each having an indoor heat exchanger installed therein; at least one outdoor device connected to the at least one indoor device by a refrigerant flow path, and each having a water-refrigerant heat exchanger that provides heat exchange between a refrigerant and heat source water and an outdoor device controller installed therein; a heat source water flow path connected to each water-refrigerant heat exchanger; a pump installed on the heat source water flow path; a variable flow valve installed on the heat source water flow path; a central controller that controls the at least one outdoor device; and a variable flow valve control board that regulates an opening degree of the variable flow valve and a flow rate of heat source water.

Abstract: A cooling system for an appliance includes an evaporator stage, a compressor stage coupled to the evaporator stage and a condenser stage coupled to the compressor stage. The condenser stage includes a condenser and a condenser cooling fan for cooling the condenser, and a condenser loop coupled between the condenser stage and the evaporator stage. A humidity sensor is configured to detect a humidity level in an area of the cooling system and a controller is configured to cycle an operating state of the condenser cooling fan from ON to a low speed or OFF prior to an end of a cooling cycle.

Abstract: A wheel loader is provided with a cab, an air conditioning unit, a cooling fan which has a condenser and a compressor, an air conditioning switch which receives the operation or non-operation of the compressor, a temperature setting portion which sets a set temperature inside the cab, a room temperature sensor which detects a room temperature inside the cab, and a controller. In a case where the air conditioning switch is operated and the room temperature is higher than a set temperature, the controller maintains the rotation amount of the cooling fan at a limited rotation amount or more.

Abstract: An air conditioning apparatus includes a refrigerant circuit, an operation controlling device and a liquid refrigerant accumulation determining device. The refrigerant circuit has an accumulator. The operation controlling device performs normal operation control where each device of the heat source unit and the utilization unit are controlled in accordance with operating load of the utilization unit, and refrigerant quantity determination operation control where properness of quantity of the refrigerant in the refrigerant circuit is determined while performing the cooling operation. The liquid refrigerant accumulation determining device determines whether or not liquid refrigerant is accumulating in the accumulator. When it has been determined that liquid refrigerant is accumulating in the accumulator, liquid refrigerant accumulation control is performed to eliminate liquid refrigerant accumulation in the accumulator.

Abstract: The present invention relates to an air-conditioning apparatus which is capable of performing a cooling operation in a stable manner in an environment having a low outside temperature. The air-conditioning apparatus according to the present invention comprises: a housing including an inlet, a bypass inlet, and an outlet; a fan configured to introduce air into the housing and discharge the air from the housing; a heat-exchange flow path deposed between the inlet and the outlet; a heat exchanger disposed at the heat exchange flow path; and a bypass flow path disposed between the bypass inlet and the outlet.

Abstract: A refrigerator with a condenser and a fan for the forced ventilation of the condenser, the refrigerator including a fan control circuit for controlling the fan to provide variable throughflow of air from the fan and an assembly for measuring temperature in operative communication with the fan control circuit for operating the fan in a temperature-dependent manner.

Abstract: Methods and systems for controlling the operation of condenser fans are provided. At most discharge pressures, the operation of the condenser fans may be controlled based on a capacity of the compressor system. To adjust operation of the condenser fans, the speed of the fans and/or the number or operational fans may be adjusted. The control of the condenser fans based on compressor system capacity may be overridden at compressor discharge pressures that rise above a high pressure level and fall below a low pressure level. At the high and low discharge pressures, the fan speed and/or number of operating fans may be adjusted based solely on the discharge pressure rather than on the compressor system capacity.

Abstract: The refrigeration system of this invention utilizes a water cooled condenser which is made of multiple water pans with refrigeration coil soldered underneath for multi-stages cooling. The water pans are stacked on top of each other with the hottest coil located at the bottom. The bottom water pan dries up water faster than the other water pans since it has the hottest coil soldered underneath. Once the water level of the bottom water pan is low enough to be refilled, the supply water fills in from the top water pan and propagating downward to the water pan down below until it reaches the water pan at the bottom. The water refilling ceases once the bottom water pan is full. The unwanted heat from a refrigeration system is transferred from the refrigerant to the water, and then from the water to the air by evaporation.

Abstract: A supplementary air conditioning system includes an indoor heat exchanger and an outdoor heat exchanger. The indoor heat exchanger is fanless and includes indoor tubes installed so as to be inclined to a ceiling of a room. The indoor tubes make diagonal contact with a high-temperature air zone in an upper part of the room and refrigerant inside the indoor tubes is heated by the air zone so as to boil and vaporize and air in the air zone flows down through the indoor heat exchanger. The external heat exchanger includes outdoor tubes installed outside at a higher position than the indoor tubes and are connected to the indoor tubes via connecting pipes with no compressor therebetween. The outdoor tubes condense and liquefy the refrigerant boiled and vaporized in the indoor tubes and return the refrigerant to the indoor tubes.

Abstract: Generally, a variable fan speed control in an HVAC system is described. Such methods and systems to control fan speed can in turn improve efficiency of the HVAC system by minimizing power consumption, for example of the compressor. The control scheme is based on various operating conditions of compressor load and ambient air temperature, which are used to determine an optimum fan speed.

Abstract: The disclosure provides an apparatus for heating water and dehumidifying air and a water heating and air processing system. In one embodiment, the apparatus includes: (1) a refrigeration circuit including an evaporator, a first condenser and a compressor, (2) a refrigerant-water heat exchanger having a second condenser fluidly coupled to the refrigeration circuit and (3) a control valve operatively connected to the refrigeration circuit to either direct flow of the refrigerant through the first condenser during a dehumidification mode or through the second condenser during a water heating mode.

Abstract: Described herein is a automotive air-conditioning system configured to implement a sub-critical refrigerating cycle and comprising a condenser and a fan associated thereto, a compressor, an evaporator, an expansion valve of the non-electronically-controlled type, and an electronic control system configured to receive a signal indicative of the ambient temperature outside the vehicle and to generate a control signal for the fan of the condenser on the basis of the ambient temperature outside the vehicle.

Abstract: Controlling a modulating gas furnace by monitoring a differential pressure associated with the modulating gas furnace using a low pressure limit switch configured to actuate at a first pressure, an intermediate pressure limit switch configured to actuate at a second pressure, and a high pressure limit switch configured to actuate at a third pressure, the second pressure being between the first and third pressure, selectively operating the modulating gas furnace in one of a cycling mode, a modulating mode in a lower range, and a modulating mode in an upper range, the modulating mode in the lower range being associated with an output capacity range between the output capacity ranges of the cycling mode and the modulating mode in the upper range, and selectively operating the furnace in response to at least one of the low pressure limit switch, the intermediate pressure limit switch, and the high pressure limit switch.

Abstract: A refrigeration apparatus includes a condensing unit, a flow distributor, and an evaporator connected to the condensing unit via the flow distributor. A pressure detector is configured to detect condensation pressure of the refrigerant. A calculation unit is configured to calculate a target condensation pressure of refrigerant necessary for the refrigerant to be an evaporation temperature in the evaporator. A controller is configured to control the condensing unit so that the condensation pressure of the refrigerant becomes equal to or more than the target condensation pressure.