Abstract: Method and system for controlling a compressor and a supply fan in a heating, ventilating and air conditioning (HVAC) system are disclosed. The system includes a compressor having a startup state and a running state, a supply fan, and a controller configured to control the compressor and the supply fan in the HVAC system. The compressor and the supply fan are controlled based on a dehumidification map and/or an efficiency map. The system also includes a cooling coil configured to receive a fluid in heat exchange relationship with refrigerant from an evaporator to cool air. The supply fan is configured to deliver the cooled air from the cooling coil to a conditioned space as supply air.

Abstract: A refrigeration system includes a free cooling system having an air-cooled heat exchanger, where the air-cooled heat exchanger includes a fan configured to move air over coils of the air-cooled heat exchanger to remove heat from a coolant flowing through the air-cooled heat exchanger, and a mechanical cooling system with a refrigerant loop that includes an evaporator, a compressor, and a condenser disposed along the refrigerant loop, where the compressor is configured to circulate a refrigerant through the refrigerant loop, and wherein the evaporator is configured to receive the coolant and transfer heat from the coolant to the refrigerant. The refrigeration system also includes a controller configured to adjust a fan speed of the fan up to a threshold fan speed, to initiate operation of the compressor when the fan speed reaches the threshold fan speed, wherein the fan speed and a compressor speed of the compressor are based at least on an ambient air temperature and a cooling load demand.

Abstract: A heating, ventilation, and/or air conditioning (HVAC) system has a first variable refrigerant flow outdoor unit, a first ducted variable speed indoor unit configured to selectively exchange refrigerant with the first variable refrigerant flow outdoor unit, and a second indoor unit configured to selectively exchange refrigerant with the first variable refrigerant flow outdoor unit.

Abstract: A system includes a variable-capacity compressor operable in a first capacity mode and in a second capacity mode that is higher than the first capacity mode. A variable-speed blower is operable at a first speed and at a second speed that is higher than the first speed. A control module is configured to (i) receive indoor relative humidity data corresponding to an indoor relative humidity (ii) switch the variable-capacity compressor between the first capacity mode and the second capacity mode based on a demand signal from a thermostat and the indoor relative humidity and (iii) switch the variable-speed blower between the first speed and the second speed based on the demand signal from the thermostat and the indoor relative humidity.

Abstract: An air conditioning system and a method of operating the same are provided. The air conditioning system includes a refrigeration loop having a variable speed compressor for circulating a refrigerant through an outdoor heat exchanger, a first expansion device, a hybrid heat exchanger, a second expansion device, and an indoor heat exchanger. The air conditioning system is operated in one of four modes depending on the indoor temperature and humidity relative to target values. The modes include an air conditioning mode, a dehumidification mode, an idle mode, and a reheat mode in which the first expansion device is fully opened and the second expansion device throttles the refrigerant to achieve a target temperature difference across the hybrid heat exchanger.

Abstract: A system includes a variable-capacity compressor operable in a first capacity mode and in a second capacity mode that is higher than the first capacity mode. A control module is configured to switch the variable-capacity compressor between the first capacity mode and the second capacity mode based on a demand signal from the thermostat. The control module determines a number of previous consecutive operating cycles of the variable-capacity compressor in the first capacity mode within a predetermined period of time. The control module operates the variable-capacity compressor in the second capacity mode in response to the number of previous consecutive operating cycles of the variable-capacity in the first capacity mode within the predetermined period of time exceeding a predetermined threshold.

Abstract: An engine driven heat pump includes an outdoor fan and an engine cooling water pump, each of which is driven by the generation power of a generator, and after a lapse of a first predetermined time from a predetermined actuation time of an engine, the output power from the generator is output-controlled, and the power output control is started so as to obtain the generation power, and when it is determined that the generation voltage after the start of the power output control is equal to or higher than a predetermined voltage, the engine cooling water pump is driven, and after a lapse of a second predetermined time from a predetermined drive time of the engine cooling water pump, the outdoor fan is driven, and after a lapse of a third predetermined time from a predetermined drive time of the outdoor fan, the output control of the inverter is started.

Abstract: A system and method of heat exchanger freeze protection for an HVAC system by operating an indoor unit assembly and an outdoor unit assembly in a cooling mode and operating a fan at an initial airflow, operating a temperature sensor to measure a temperature value of a heat exchanger, at the expiration of a first predetermined time period, determining whether the temperature value is less than or equal to a first temperature preset value, determining whether a current airflow multiplier is equal to a maximum airflow multiplier limit, increasing the current airflow by an airflow offset multiplier if the current airflow multiplier is less than or equal to the maximum airflow multiplier limit and the temperature value is less than or equal to the first temperature preset, and operating the fan at an increased airflow to move more air across the heat exchanger.

Abstract: A variable capacity type rotary compressor and a cooling apparatus having the same, and an operation method thereof are provided. In the variable capacity type rotary compressor and the cooling apparatus having the same, a discharge pressure is supplied to a rear side of a second vane disposed in the compressor after the discharge pressure is higher than a reference pressure, so that the compressor is switched from a saving mode into a power mode. The second vane is press-contacted with a second rolling piston with fast and accurately moving without vibration, resulting in preventing beforehand noise occurrence or efficiency degradation due to the vibration of the second vane when the compressor or the cooling apparatus having the compressor is operated in the power mode.

Abstract: Heating, ventilating and air conditioning are provided to a temporary, flexible shelter, especially in a rugged, remote and/or extreme environment, including locations and/or conditions where access to electric power may be limited and/or expensive. A portable system may include a light weight HVAC unit, with variable-speed components that are dynamically managed for efficiency, reliability and safety, and a flexible, self-insulating duct for connecting the HVAC unit to the temporary shelter.

Abstract: A method of automatically detecting an anomalous condition relative to a nominal operating condition in a vapor compression system. An expected input power function in the form of a hyperplane is calculated based on three temperature readings: an intake temperature from an intake area of the condenser unit, a return temperature from an intake area of an evaporator unit, and a supply temperature from a supply output area of the evaporator unit. The function produces an estimate of the expected input power consumed by the compressor unit, and this expected input power is compared with an actual input power measured from the compressor unit. If the expected input power deviates from the measured input power by more than a predetermined tolerance, an indication is stored and communicated that an anomalous condition, such as a refrigerant loss, condenser unit fouling, or a malfunctioning fan, exists in the vapor compression system.

Abstract: A climate control system for a storage unit. The system includes a reverse cycle chiller; a fluid supply line in fluid communication with an outlet of the fluid side heat exchanger; a fluid return line in fluid communication with an inlet of the fluid side heat exchanger and the fluid supply line; at least one hydronic coil in optional fluid communication with the fluid supply line and the fluid return line, the at least one hydronic coil located in a room to be controlled; a controller in communication with the reverse cycle chiller and the at least one hydronic coil; an ambient temperature sensor in communication with the controller; an ambient humidity sensor in communication with the controller; a room temperature sensor in communication with the controller, the room temperature sensor positioned in the room; and a room humidity sensor in communication with the controller, the room humidity sensor positioned in the room. A method of controlling the climate in a storage unit is also described.

Abstract: A refrigeration apparatus (1) is provided with a refrigerant circuit (1E) along which are connected a compressor (2), an outdoor heat exchanger (4), an expansion mechanism, an indoor heat exchanger (41) for providing room air conditioning, and a cooling heat exchanger (45, 51) for providing storage compartment cooling. The refrigerant circuit (1E) includes a discharge side three way switch valve (101) for varying the flow rate of a portion of the refrigerant which is discharged out of the compressor (2) and then distributed to the indoor heat exchanger (41) and the outdoor heat exchanger (4) during a heat recovery operation mode in which the indoor heat exchanger (41) and the outdoor heat exchanger (4) operate as condensers. As a result of such arrangement, even when the amount of heat obtained in the cooling heat exchanger (45, 51) exceeds the amount of heat required in the indoor heat exchanger (41), surplus heat is discharged without excessive decrease in the discharge pressure of the compressor (2).

Abstract: A refrigerant system adjusts, in a coordinated prioritized manner, the variable capacities of a compressor, evaporator fan and a condenser fan to minimize the system's overall power consumption while maintaining a comfort zone within a target comfort range. The target comfort range is defined by desired temperature and humidity limits. When the comfort zone is within the target comfort range, the system periodically attempts to reduce the compressor capacity. If the attempt succeeds, the evaporator fan capacity is then minimized. The condenser fan capacity can also be minimized provided the refrigerant system can maintain at least a minimum saturated suction temperature of the refrigerant flowing from the condenser to the compressor.

Abstract: A multi-stage compressor is provided that reliably prevents liquid compression in a higher stage compression mechanism and also prevents compression efficiency degradation resulting from overheating of injection refrigerant and from the lubricating oil being raised up together with the injection refrigerant. An injection circuit is branched into a plurality of circuits. A first circuit thereof is communicatively connected to an inside space of a closed housing that is at the same side as the higher stage compression mechanism with respect to an electric motor, and a second circuit is communicatively connected to an inside space of the closed housing that is opposite from the higher stage compression mechanism with respect to the electric motor. The first circuit and the second circuit are provided with a switching mechanism for switching the injection circuit to the first circuit or the second circuit according to the dryness of the injection refrigerant.

Abstract: A method of controlling a HVAC system for a hybrid vehicle having a refrigerant compressor driven by an engine is disclosed. The method may comprise: determining a requested air conditioning operating point for a passenger compartment; estimating a time to reach the requested operating point; based on the previous steps, estimating a maximum allowed compressor off time; determining if the allowed compressor off time is greater than a minimum engine off time; if the allowed compressor off time is greater than the engine off time, determining if the vehicle is entering an allowable engine off mode; if so, commencing engine shut-off mode; if engine shut-off is anticipated, prior to commencing the shut-off mode, adjusting the HVAC system to maximize cooling of the passenger compartment with minimum energy usage; and if the engine shut-off is commenced, monitoring the HVAC system to determine when engine restart is needed to maintain comfort.

Abstract: In an air conditioner provided with a capacity variable compressor unit including an inverter, the capacity of the capacity variable compressor unit is controlled in response to air-conditioning load data including temperature difference between a set temperature and an indoor temperature. An inverter frequency for controlling an operation condition of the compressor unit is controlled by limiting a frequency obtained in response to the air-conditioning load data to a value less than a maximally allowable capacity stored in memory means such as ROM or EEPROM.

Abstract: A method and apparatus for controlling a vehicle HVAC system to automatically defog a windshield glass and to prevent fogging or condensation of the windshield glass. The ambient air temperature and vehicle speed are measured and used to determine a windshield glass temperature. The in-cabin air temperature and relative humidity are measured and used to determine a dewpoint. An dewpoint margin is calculated to compensate for sensor accuracy and fog predictability. A fog margin, which is based upon calculated windshield glass temperature and dewpoint, is calculated and used, in conjunction with the dewpoint margin, to control the HVAC system to anticipate potential fogging conditions and to scale the intensity of the HVAC system response based upon the severity of fogging conditions.

Abstract: Disclosed herein is a heat pump. The heat pump comprises a compressor, indoor and outdoor heat exchangers for condensing or evaporating refrigerant compressed by the compressor according to cooling or heating operation mode, a four-way valve for guiding the flow of the compressed refrigerant to the indoor heat exchanger or the outdoor heat exchanger according to the operation mode, an expansion valve for selectively decreasing the pressure of liquid refrigerant according to the operation mode, a check valve selectively opened or closed according to the operation mode for guiding the flow of the liquid refrigerant to the expansion valve, an accumulator for preventing the liquid refrigerant from entering into the inlet of the compressor, connection pipes, and a heat exchange part for performing heat exchange between the connection pipe connected to the inlet of the accumulator and the connection pipe connected to the indoor heat exchanger.

Abstract: The present invention concerns a method for controlling the operation of an automotive HVAC system. The HVAC system includes at least a refrigerant compressor and a refrigerant evaporator. The method includes the steps of calculating an ambient air enthalpy value; comparing the calculated ambient air enthalpy value to at least one predetermined enthalpy value; and selectively changing the operation of the refrigerant compressor based on the comparison.

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

Abstract: The temperature of the air exiting an evaporator and the relative humidity of the air entering and exiting the evaporator can be calculated by using existing sensors in a vapor compression system. The temperature of the air exiting the evaporator is calculated by using the detected temperature of the air entering the evaporator, the saturation temperature of the air, and a bypass factor. The relative humidity of the air entering and exiting the evaporator are then estimated using a psychrometric chart. By using the existing sensors to determine the temperature of the air exiting the evaporator and the relative humidity of the air entering and exiting the evaporator, the load requirement of the vapor compression system can be calculated without employing additional sensors. The system capacity of the vapor compression system can be matched to the load requirement to allow the effective use of electric power.

Abstract: Electrical appliance energy consumption control methods and electrical energy consumption systems are described. In one aspect, an electrical appliance energy consumption control method includes providing an electrical appliance coupled with a power distribution system, receiving electrical energy within the appliance from the power distribution system, consuming the received electrical energy using a plurality of loads of the appliance, monitoring electrical energy of the power distribution system, and adjusting an amount of consumption of the received electrical energy via one of the loads of the appliance from an initial level of consumption to an other level of consumption different than the initial level of consumption responsive to the monitoring.

Abstract: A vapor compression system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated through the closed circuit cycle. Preferably, carbon dioxide is used as the refrigerant. Adaptive control is employed to optimize the coefficient of performance of the vapor compression system. As the system changes over time, a model that operates the system is modified. The model is determined by an adaptive control algorithm including variable coefficients. As the model changes, the variables of the adaptive control algorithm change. A control of the gas cooler is then adjusted to regulate the high pressure of the system, and therefore the coefficient of performance. In a first example, Least Mean Squares (LMS) is used to modify the variables of the adaptive control algorithm to optimize the coefficient of performance. In a second example, the coefficient of performance is optimized by a slowly varying periodic excitation method.

Abstract: A method for operating a transcritical refrigeration system wherein a more optimal compressor parameter such as output pressure, pressure ratio or power consumption is determined using heat exchanger refrigerant inflow temperatures and/or outflow temperatures and also the enthalpy change across the evaporator and adjusting the compressor operation or refrigerant fluid working mass accordingly.

Abstract: An improved vehicle climate control system develops a fog factor indicative of the relative potential of windglass fogging, and uses the index to schedule offsets to normal control settings of the system. The air dewpoint temperature at the front windglass is estimated based on relative humidity and a reference temperature, and the fog factor is determined as a function of the estimated air dewpoint temperature and a measure of the windglass temperature. The fog factor is used to offset an air inlet door, mode doors, refrigerant compressor capacity, discharge air temperature, and blower motor speed.

Abstract: The present invention concerns a method for cool-drying gas containing water vapor, whereby this gas is guided through the secondary part of a heat exchanger (1) whose primary part is the evaporator (2) of a cooling circuit (3) which also contains a compressor (5) which is driven by an electric motor (4), a condenser (6), an expansion means (7) between the outlet of the condenser (6) and the inlet of the evaporator (2), and whereby the above-mentioned cooling circuit (3) is thus controlled as a function of the load that the cooling capacity is adjusted without any ice being formed in the evaporator (2), characterized in that the cooling circuit is controlled by adjusting the rotational speed of the motor (4).

Abstract: An improved vehicle climate control system in which the passenger compartment temperature and humidity are controlled without requiring a humidity sensor. The control is based on the recognition that the air temperature at the evaporator outlet represents the dew point of the air supplied to the passenger compartment, and may be specified based on the desired passenger compartment air temperature to achieve a desired relative humidity in the vehicle once the desired passenger compartment temperature has been achieved. In a first mechanization, the desired relative humidity is predetermined, and the corresponding values of evaporator outlet air temperature are determined as a function of the desired passenger compartment temperature.

Abstract: A system and method of control of refrigerant air conditioning including a humidity input sensor, and a coolant velocity sensor, using a control system set with a set point whereby to maintain a maximum evaporator temperature set point varying to suit each heat and moisture load condition over a range of conditions compatible with high engineering standards of performance.

Abstract: In a cooling apparatus for cooling air, in order to improve heat absorption by a refrigerant, a metal having a high heat conductivity such as copper or aluminum is generally utilized as a constituent material of a heat exchanger. However, due to high heat conductivity, the temperature of a refrigerant becomes equal to the surface temperature of the heater exchanger, so that a space inside a refrigerator or a room is dried. Further, since the amount of latent heat of air decreases due to drying, cooling cannot be effected unless a temperature difference of 10° C. or more is produced between the inlet and outlet of the heat exchanger. An object of the present invention is to realize a cooling apparatus which does not decrease humidity and which produces a smaller temperature difference between an inlet and an outlet of a heat exchanger, i.e., reduces energy loss.

Abstract: An air conditioning system (10) for a passenger compartment of a motor vehicle having a windscreen comprises a first heat exchanger (14) positionable outside the passenger compartment; a second heat exchanger (18) positionable inside the passenger compartment; an expansion device (16) positioned in a first fluid passage (22) between the heat exchangers; an electronically controlled variable stroke compressor (12) for pumping fluid into the second fluid passage and either in a first direction (X) or in a second direction (Y); reverse flow means (32) in the second fluid passage for controlling the direction of the flow of fluid; first sensing means (36, 40) providing a first output signal indicative of the dewpoint temperature of the air leaving the second heat exchanger; second sensing means (53; 44,46,48) providing a second output signal indicative of the temperature of the windscreen; and control means (26,30) electrically connected to the first and second sensing means and to the compressor for receiving th

Abstract: An air conditioning system (10) for a passenger compartment of a motor vehicle comprises a first heat exchanger (14) positionable outside the passenger compartment; a second heat exchanger (18) positionable inside the passenger compartment; an expansion device (16) positioned in a first fluid passage (22) between the heat exchangers; an electronically controlled variable stroke compressor (12) for pumping fluid into the second fluid passage and either in a first direction (X) or in a second direction (Y); reverse flow means (32) in the second fluid passage for controlling the direction of the flow of fluid; first sensing means (36) providing a first output signal indicative of the actual temperature of the air leaving the second heat exchanger; second sensing means (40) providing a second output signal indicative of the humidity of the air leaving the second heat exchanger; third sensing means (46) providing a third output signal indicative of the temperature of the air in the passenger compartment; and contr

Abstract: A fresh air unit. The unit comprises: a housing having an airstream flowing therethrough; a pre-cooling portion, and dehumidification portion. The pre-cooling portion is located within the housing and reduces the temperature and specific humidity of a gas in the airstream to a target zone on a psychrometric chart. The dehumidification portion is also located in the housing downstream of the pre-cooling portion. The dehumidification portion removes a selected amount of moisture from the gas and reheats the gas a selected amount of sensible heat gain.