Abstract: A method controls a recirculation position of a return vent in an HVAC system for a vehicle with a compressor driven by a start/stop engine. A partial s recirculation position is set according to a basic recirculation strategy while the engine is operating. An auto stop event is entered at a time with the compressor operating. A full recirculation position is set during the stop event if a plurality of low fogging probability indicators are true. The low fogging probability indicators include a sensed ambient temperature being above a predetermined temperature, a sensed state of a windshield wiper being an off state, and a sensed sunload being above a predetermined sunload.

Abstract: A refrigeration control apparatus for a space includes a heat exchanger mounted in the space and having an inlet and an outlet for a cooling medium to be introduced into and exhausted from the heat exchanger; at least one fan assembly mounted in the space and operatively associated with the heat exchanger for moving an airflow over the heat exchanger; a sensor assembly mounted in the space for sensing a temperature of at least the space; and a controller having an electrical connection to the at least one fan and the sensor assembly to control operation of the fan responsive to the temperature of at least the space. A method is also provided for controlling the temperature of the space.

Abstract: A refrigeration system includes a compressor having a first stage (20a) and a second stage (20b); a motor (22) driving the compressor; a heat rejecting heat exchanger having a fan (44) drawing ambient fluid over the heat rejecting heat exchanger, the heat rejecting heat exchanger including an intercooler (43) and a gas cooler, the inter-cooler coupled to an outlet of the first stage and the gas cooler (41) coupled to an outlet of the second stage; a flash tank (70) coupled to an outlet of the gas cooler; a primary expansion device (55) coupled to an outlet of the flash tank; a heat absorbing heat exchanger (50) coupled to an outlet of the primary expansion device, an outlet of the heat absorbing heat exchanger coupled to the suction port of the first stage; and a controller (100) for implementing a pulldown mode, a control mode and a staging logic mode.

Abstract: A cooling system includes an air conditioner capable of cooling a predetermined space and changing an air volume or set temperature; one or more electronic devices disposed in the predetermined space and including a fan of variable rotational speed; a temperature sensor configured to detect temperature of the electronic devices; and a control apparatus configured to select, based on an increase in the detected temperature, whether to increase the air volume or decrease the set temperature of the air conditioner or to increase the rotational speed of the fan, with reference to air-conditioner information indicating a relationship between cooling performance and power consumption of the air conditioner and fan information indicating a relationship between cooling performance and power consumption of the fan.

Abstract: A method for controlling a fan in a vehicle includes comparing the current temperature of at least a first device and a second device to multiple temperature ranges for each of said devices and determining on the basis of said comparisons whether fan speed should be changed, increasing fan speed to a maximum fan speed if at least one of the comparisons indicates that the maximum fan speed is desired, increasing fan speed to a reference fan speed if at least one of the comparisons indicates that an increase in fan speed less than the maximum fan speed is desired, and decreasing fan speed to a reference fan speed if the comparisons indicate that a decrease in fan speed is desired.

Abstract: An HV_ECU executes a program including: switching, if an operation is in an A/C intake mode and absolute value of temperature difference Thi?Tlo is larger than a predetermined value A and temperature Thi is smaller than a predetermined value B, the operation mode to a compartment intake mode; switching, if the operation is in the compartment intake mode, the compartment intake mode is requested to prevent increase in temperature difference, the absolute value of temperature difference Thi?Tlo is larger than a predetermined value A and temperature Thi is equal to or larger than the predetermined value B, the operation mode to an A/C intake mode; and executing a normal intake mode switching control.

Abstract: A refrigerator is provided having a refrigeration system including a variable speed compressor, a condenser, a condenser fan, an evaporator, a variable speed evaporator fan. The refrigerator further includes multiple temperature sensors that communicate with an electronic microprocessor-based control system that in turn controls the operation of the refrigerator system based on the information provided by the multiple temperature sensors.

Abstract: An object to save power and control engine startup and shutdown while improving the cabin environment with a simple configuration. A vehicular air-conditioning control device detects an outside air temperature; finds from an eco-running map a time TA until odor and so forth corresponding to the outside air temperature arises, an eco-runnable TB extended by shutting down a blower, and a time TC at which to shut down the operation of the blower fan; shuts down the blower fan at the time TC during eco-running; and, when the eco-runnable time TB elapses, causes the blower fan to operate, issues an engine startup request, and initiates refrigerant circulation by a compressor. Thus, by operating the blower fan for a predetermined time when the engine has been shut down by eco-running, the comfort of the cabin environment can be improved and the eco-runnable time can be extended to save power.

Abstract: A refrigerant system includes a compressor, an evaporator, an expansion valve, an accumulator or equivalent, one or more earth loops, and auxiliary heat removal means. The auxiliary means comprises a fan and fan coil and the fan forces air between multiple tubes of the fan coil to remove unwanted heat from the hot vapor exiting the compressor.

Abstract: A control method of a dryer is disclosed. A control method of a dryer including a heat pump having a inverter compressor includes determining a driving condition of the dryer; and adjusting at least one of an electric power supplied to the inverter compressor and a driving velocity of the compressor based on the driving condition.

Abstract: An Electronically-Controlled Register vent (ECRV) that can be easily installed by a homeowner or general handyman is disclosed. The ECRV can be used to convert a non-zoned HVAC system into a zoned system. The ECRV can also be used in connection with a conventional zoned HVAC system to provide additional control and additional zones not provided by the conventional zoned HVAC system. In one embodiment, the ECRV is configured have a size and form-factor that conforms to a standard manually-controlled register vent. In one embodiment, a zone thermostat is configured to provide thermostat information to the ECRV. In one embodiment, the zone thermostat communicates with a central monitoring system that coordinates operation of the heating and cooling zones.

Abstract: A system and a method for controlling an operation of a vapor compression system are disclosed, such that a performance of the system measured in accordance with a metric of the performance is optimized. A control signal is modified with a modification signal including a perturbation signal having a first frequency, wherein the control signal controls at least one component of the vapor compression system. A metric signal representing a perturbation in the performance of the system caused by the modification signal is determined, wherein the metric signal has a second frequency substantially equal to the first frequency. The control signal is adjusted based on a function of a phase between the perturbation signal and the metric signal, such that the performance is optimized.

Abstract: A heating, ventilation, and/or air conditioning (HVAC) system includes a bypass duct configured to selectively receive a bypass airflow therethrough in response to a supply air pressure of the HVAC system and a supply air temperature of the HVAC system.

Abstract: Methods for controlling an economizer of an HVAC system are disclosed. An illustrative control method may include positioning one or more controllable dampers in first and second configurations such that a mixed air stream has first and second mixing ratios of incoming outside air to return air. First and second measures related to the temperature of the mixed air stream may be recorded when the dampers are in each of the first and second configurations. Based on the recorded first and second measures, it may be determined whether and/or how much of the incoming outside air to admit into the economizer via the one or more controllable dampers during subsequent operation of the HVAC system.

Abstract: A system and method of controlling an air-cooled refrigerator. The air-cooled refrigerator includes a refrigerating compartment, a refrigerating evaporator, and a refrigerating fan for circulating an air between the refrigerating evaporator and the refrigerating compartment.

Abstract: An air conditioning system for a vehicle includes a cabin air conditioning unit, a heat management unit, a temperature detecting unit, a switching unit, and a control unit. The control unit is operable to control operations of the cabin air conditioning unit, the switching unit, and the heat management unit according to temperature detection results from the temperature detecting unit, thereby regulating temperature of at least one of a passenger cabin and a heat generating component, which generates waste heat during operation thereof, of the vehicle.

Abstract: An air conditioning system comprises a housing defining a first airflow path therein between an outside air inlet over a cooling coil and an outlet for delivering outside air from said outside air inlet over said coil to the outlet, a second airflow path between a return air inlet over the cooling coil and to the outlet for delivering return air over the cooling coil, and a third airflow path between the return air inlet and the outlet for delivering return air through the housing without passing over the cooling coil. The system includes outside, return, and bypass air dampers that are sequentially moveable between open and closed positions for directing air through or preventing air from entering the first, second, and third airflow paths, respectively. A controller independently controls the opening and closing of each damper in response to data received from the sensor.

Abstract: A air channeling sub-system may include a mechanical cooling section and a direct evaporative cooling section. The direct evaporative cooling section may be downstream from the mechanical cooling section. Cooling air is channeled through the air channeling sub-system and into the room. If a first set of control conditions is met, the air channeling sub-systems is operated in an adiabatic mode. The adiabatic mode includes channeling cooling air through the direct evaporative cooling section to evaporate water into the cooling air. If a second set of control conditions is met, the air channeling sub-system is operated in a hybrid mode. The hybrid mode includes channeling cooling air through the mechanical cooling section to remove heat from the cooling air and channeling the cooling air through the direct evaporative cooling section to evaporate water into the cooling air.

Abstract: An energy saving air quality control system modulates supply fan speed by use of controlled, variable-frequency drive controls for automatic dampers or suction pressure to maintain adequate air flow across the evaporator coil at partial cooling loads. Indexing the fan speed to maintain the suction pressure of the energized coil controls the maximum relative humidity of the conditioned space. Demand ventilation in the system balances air quality and energy consumption by controlling the outdoor air damper in response to indoor CO2 and humidity levels.

Abstract: In accordance with embodiments of the present disclosure, a modular fluid-handling system may include an air-handling and mixing unit and a cooling unit. The air-handling and mixing unit may include an air mover plenum and a first mixing plenum. The air mover plenum may have an air mover configured to move air and the air mover plenum may air mover plenum may be configured to be in fluid communication with an outside environment via a first damper and configured to be in fluid communication with a primary structure. The first mixing plenum may be configured to be in fluid communication with the air mover plenum via a second damper and configured to be in fluid communication with the outside environment via a third damper.

Abstract: A cooling system for a room containing electronic data processing equipment includes a raised floor construction dividing the room into a plenum space underneath the raised floor and a usable space above the raised floor, an air conditioning device for feeding cooled air to the plenum space and a cooling module. The cooling module is arranged as a floor element of the raised floor and includes a fan for providing a flow of cooled air from the plenum space to the usable space, the cooling module being configured such that the flow direction of the flow is controllable. The system further includes a control device connected to the cooling module for automatically controlling the flow direction of the flow.

Abstract: An evaporator assembly through which a refrigerant is circulated to transfer heat out of a volume of air in a housing in which the evaporator assembly is at least partially disposed. The evaporator assembly includes an evaporator in fluid communication with a compressor for compressing the refrigerant, a solenoid valve subassembly for controlling circulation of the refrigerant, a thermostat electrically connectable to the solenoid valve subassembly via a solenoid control circuit, one or more fans for circulating the air in the housing, and one or more fan motors for rotating the fans. Drive voltage supplied to the fan motors is controlled by a fan controller. The fan controller provides a first predetermined drive voltage to the motor drive when refrigerant is circulatable and a second predetermined drive voltage to the motor drive when refrigerant is non-circulatable.

Abstract: A cooling system includes; an evaporator evaporating a refrigerant by heat exchange with room air; a water-cooled condenser being arranged above the evaporator and condensing the refrigerant by heat exchange with cold water; a cold-water flow control valve controlling the flow rate of the cold water supplied to the water-cooled condenser; a refrigerant cooling tower being arranged above the evaporator and condensing the refrigerant by heat exchange with outside air; a blower being arranged at the refrigerant cooling tower and blowing the outside air; a refrigerant-temperature detector detecting the temperature of the refrigerant condensed by the water-cooled condenser and/or the refrigerant cooling tower; and a controller changing at least one of the opening in the cold-water flow control valve and the rotational speed of a motor in the blower according to the temperature.

Abstract: An electric vehicle battery heater includes a housing having a coolant inlet and a coolant outlet. A heating element is positioned within the housing in a heat transfer relationship with coolant for transferring heat to an electric vehicle battery. A thermistor is positioned in the housing to output a signal indicative of a temperature of the battery coolant. A controller energizes the heating element when the signal represents that the coolant temperature is less than a predetermined lower limit.

Abstract: A closed loop cooling system and apparatus for controlling a fluid flow rate through the closed loop cooling system, the apparatus comprising a heat exchanger coupled to at least one heat generating device for removing waste heat from the heat generating device, at least one pump for circulating the fluid, a heat rejector for receiving the fluid, at least one fan for removing waste heat from the heat rejector, at least one temperature sensor coupled to the heat generating device to measure the temperature value of the at least one heat generating device, and a controller electrically coupled to the at least one pump, the at least one fan, and the at least one temperature sensor for receiving the temperature value to selectively control the fluid flow rate and the air flow rate, based on the temperature value.

Abstract: An active air cleaning controller is connected to a forced air heating, ventilation and air conditioning (HVAC) system. The active air cleaning controller uses call signals from a thermostat to the HVAC system and/or sensor signals to determine when, and for how long, the blower of the HVAC system has been active and whether to independently activate the blower. The active air cleaning controller uses at least the collected information regarding the blower run time to determine when to activate the blower, in addition to its use within the HVAC system, to cycle and thus clean the air in a living environment independently of call signals used to activate heating and/or cooling functions of the HVAC system.

Abstract: A system for regulating gas flow for a computer room containing computer components includes vents configured to direct gas from a gas supply toward the computer components, sensors disposed and configured to provide information regarding at least a first property associated with the computer components, and a controller coupled to the sensors and the vents and configured to effect a change in gas flow through a second one of the vents in accordance with a first value of the first property associated with a first of the computer components.

Abstract: A method of controlling cooling of a processor, including monitoring at least one parameter of a current status of the processor and determining in which of a plurality of value ranges the at least one parameter of the current status of the processor is located. If the at least one parameter is located in a first range, determining a first desired value for a cooling parameter, based on the processor temperature, using a first method, determining a second desired value for the cooling parameter, based on the processor temperature, using a second method, in which the value of the cooling parameter increases, in a manner indicating more cooling, from a low value for a low processor temperature to a higher value for a higher processor temperature and selecting a value of the cooling parameter as a function of the first and second desired values.

Abstract: An integrated air conditioner that controls the operation of a water feed device according to the mode of use. The air conditioner includes a control section that determines whether or not exhaust heat from a condenser 3 is being released outdoors through an exhaust duct 7 according to whether or not an air intake duct 26 or an exhaust duct 7 is fitted, operates a water feed device 8 for leading drain wafer collected in the drain pan to the condenser 3 during both of a cooling operation and a dehumidifying operation if it determines that the heat to be released from the condenser 3 is being released outdoors, and operates the water feed device 8 during the cooling operation and stops the operation of the water feed device 8 during the dehumidifying operation if it determines that the exhaust heat from the condenser 3 is not being released outdoors.

Abstract: A dehumidification apparatus comprises an air inlet configured to receive an inlet airflow that is separated into a process airflow and a bypass airflow. An evaporator unit is operable to cool the process airflow by facilitating heat transfer from the process airflow to a flow of refrigerant as the process airflow passes through the evaporator unit. A condenser unit operable to (1) reheat the process airflow by facilitating heat transfer from the flow of refrigerant to the process airflow as the process airflow passes through a first portion of the condenser unit, and (2) heat the bypass airflow by facilitating heat transfer from the flow of refrigerant to the bypass airflow as the bypass airflow passes through a second portion of the condenser unit. The process airflow is discharged into the structure via a process airflow outlet and the bypass airflow is discharged into the structure via a bypass airflow outlet.

Abstract: An air dehydration and heating device can include a first evaporator serpentine and a second evaporator serpentine in parallel and in series with at least one condenser serpentine; a first outside air intake damper for the first evaporator serpentine and a second outside air intake damper for the second evaporator serpentine; a fan motor to drive a fan; a drying air outlet duct to receive air moved by the fan, the air having passed through at least one of the first evaporator serpentine and the second evaporator serpentine and at least one of the at least one condenser serpentine; a return drying air intake damper in a return drying air intake duct; and a processor to control temperature and humidity of drying air in the drying air outlet duct.

Abstract: A method maintains, in a compressed gas dryer, working through condensation of moisture contained in the air and with dryer thermal load demands, an operation that keeps the temperature of the evaporator, near the outflow of the compressed air, in range between a value sufficiently high to avoid freezing the moisture in the compressed air and a value sufficiently low to avoid compromising the effect of moisture condensation generated by the decreased temperature. This objective is achieved with a compressor by-pass conduit on which is mounted a selectively controllable adjusting valve. The operation includes: measurement of the evaporation temperature (Tev), and verification the temperature is higher than a preset value (Set_Tev); starting the compressor; opening the valve for a preset time, and then closing it; verification that the temperature is higher than a preset value; if the time elapsed is longer than a predetermined time, then the valve is opened.

Abstract: Systems and methods of automatically operating dehumidifiers in response to dehumidifier operating conditions are disclosed herein. A method of operating a dehumidifier configured in accordance with one embodiment includes directing air flow through the dehumidifier at a first volumetric flow rate while the dehumidifier is operating at a first operating condition. The method further includes changing the first volumetric flow rate to a second volumetric flow rate when the first operating condition of the dehumidifier changes to a predetermined second operating condition.

Abstract: An inlet air flow guide for a condensing unit of an air cooled direct expansion (ACDX) air conditioning unit. The flow guide has a panel having at least a portion spaced from a surface of the condensing unit to define a plenum for cooling air to enter the condensing unit from one side. A condensing unit of an ACDX air conditioning unit has a refrigerant cooling coil disposed in an opening, and the inlet air flow guide defines a plenum to provide an air flow passage to the opening from one side thereof. According to a method, the inlet air flow guide is installed onto the condensing unit of an ACDX air conditioning unit, wherein a panel of the flow guide has at least a portion spaced from a surface of the condensing unit to define a plenum for cooling air to enter the condensing unit from one side.

Abstract: Systems and methods for regulating the amount of outdoor air that is introduced into a building are shown and described. These systems and methods utilize extremum seeking control logic to vary the flow of outdoor air into the building in response to cooling load determinations.

Abstract: A primary beverage cooling circuit for refrigerating a fluid used in a secondary beverage cooling circuit that cools beverage in a beverage conduit by pumping the fluid through a heat exchange conduit adjacent the beverage conduit to transfer heat therebetween, the primary beverage cooling circuit comprising a refrigerant circuit containing a refrigerant circulating through: a heat exchanger in heat transfer communication with the fluid to cool the fluid; a variable displacement compressor for circulating the refrigerant through the refrigerant circuit; a cooling device for cooling the refrigerant; and a valve for controlling the volume of fluid into the heat exchanger; the primary beverage cooling circuit further comprising a controller for controlling the operation of the compressor and/or the cooling device and/or the valve based on one or more measurements from temperature and/or pressure sensors in the refrigerant circuit to thereby operate the system on an efficient basis

Abstract: An operation unit for a vehicle air conditioner includes a display device, a setting input portion of a control parameter of the air conditioner other than a set temperature, an obtaining portion configured to obtain a present set value of the control parameter, and an operating state identification portion configured to identify whether an air-conditioning operating state is in a plurality of predetermined operating states of the air conditioner. In the operation unit, a moving pattern of a pointer of the display device is changed according to the operating state of the air conditioner. For example, a pointer operation control portion can be configured to control an operation of a pointer driving motor such that the pointer moves on a dial of the display device at different moving speeds according to the air-conditioning operating state.

Abstract: There is provided a refrigeration cycle apparatus in which an outdoor heat source unit, an indoor unit, and a water heating unit are connected, and an air conditioning operation and a water heating operation can be performed separately, and an exhaust-heat recovery operation can be performed by simultaneously performing air cooling and water heating. The outdoor heat source unit includes a compressor for compressing refrigerant, a refrigerant air-heat exchanger that performs heat exchange between the refrigerant and outside air, a fan for cooling the refrigerant air-heat exchanger, a control device that includes an inverter device for driving the compressor, and a heat sink for dissipating heat of the inverter device, and a switching element in the inverter device is constituted by an element formed by a wide bandgap semiconductor.

Abstract: The present invention provides a method for enhancing dehumidification of a conditioned space, while optimizing the effectiveness of Indoor Air Quality (IAQ) devices that are present in the HVAC system. After the system compressor is shut off, the actual space humidity is compared to the desired humidity. If the actual humidity is very close to or lower than the desired level the indoor blower (air handler) is allowed to continue running. However, if the actual humidity is greater than the desired level by a specified amount, the blower is forced off for a period of time proportional to the difference between the actual and desired humidity. At the next compressor activation, the blower is allowed to run as normal.

Abstract: An exhaust air removal system and method for use with a rack or enclosure containing equipment is provided. The system and method are configured for removal of exhaust air vented from equipment during operation to thereby remove heat from the equipment. In one aspect, the system includes a fan unit preferably configured to serve as a back door of an equipment rack or enclosure and configured to provide access to an interior of the rack or enclosure. The fan unit provides multiple fans coupled to internal exhaust ducts that are arranged to draw and to remove exhaust air vented from rack-mounted equipment. The fan unit is further configured to vent exhaust air to an area external to a rack or enclosure, such as an external exhaust duct or plenum. Removal of hot and warm exhaust air vented from rack-mounted equipment enables the equipment to operate effectively, drawing sufficient amounts of cooling air to meet its cooling requirements.

Abstract: An adjustable orifice for use in an aircraft air conditioning system includes a first orifice element which has an orifice frame as well as a first orifice area. When the orifice is assembled at a duct, the first orifice area of the first orifice element leaves open a part of a cross section of the duct. The orifice also includes a second orifice element with a second orifice area. When the orifice is assembled at the duct, the second orifice area of the second orifice element leaves open a part of the cross section of the duct. The second orifice element is rotatable about an axis, so that the second orifice area is rotatable relative to the first orifice area in order to set a desired flow cross section in the duct.

Abstract: A method of controlling the operation of an evaporative air cooler where the pads (2) of the cooler are intermittently wetted with an amount of water (14) in excess of the capacity of the pads (2) to absorb and retain during each wetting operation of the pad. The airflow (20) through the pads during intermittent wetting being limited to a velocity so as to not entrain water in the airflow during the wetting operation and the velocity of the airflow through the pads is increased after each intermittent wetting so as to raise the level of cooling output (22) of the cooler between each intermittent wetting operation.

Abstract: A vented dryer having a drum to dry damp laundry by warm process air; a first process air duct upstream of the drum; a heater to heat the process air in the first process air duct; a supply air duct leading into the first process air duct; an exhaust air duct; a second process air duct downstream of the drum and transitioning into the exhaust air duct; a blower; a first temperature sensor in the first process air duct; and a heat-buildup generator to generate a heat buildup at the first temperature sensor if a counter-flowing air current occurs.

Abstract: A cooling system constructed to cool down an accumulator mounted on a motor vehicle is herein presented. The cooling system sequentially controls an air blower to restrict the air blow to the accumulator, controls the air blow mode switchover module to switch over the active air blow mode after restriction of the air blow to the accumulator, and controls the air blower to release the restriction of the air blow to the accumulator after the switchover of the active air blow mode by the air blow mode switchover module.

Abstract: An insulated icemaking compartment is provided in the fresh food compartment of a bottom mount refrigerator. The icemaking compartment may be integrally formed with the liner of the fresh food compartment, or alternatively, may be modular for installation anywhere in the fresh food compartment. A removable bin assembly with a front cover normally seals the icemaking compartment to maintain the temperature in the compartment. A cold air duct formed in the rear wall of the refrigerator supplies cold air from the freezer compartment to the icemaking compartment. A return air duct directs a portion of the air from the icemaking compartment back to the freezer compartment. An air vent in the icemaking compartment directs another portion of air into the fresh food compartment. A control system provides for controlling refrigerator functions in a manner that promotes energy efficiency.

Abstract: A method for controlling temperature of a refrigerator including a main body having at least first and second adiabatic spaces; a refrigerant compression cycle device including an evaporator, a compressor, a condenser, and an expander installed within the main body; and a heating unit transferring heat of a refrigerant discharged from the condenser to air in the second adiabatic space, includes: measuring an internal temperature of the second adiabatic space; bypassing the refrigerant discharged from the condenser to the second adiabatic space when the measured internal temperature of the second adiabatic space is lower than a lower limit value of a pre-set temperature range; measuring ambient temperature of the condenser; and controlling an operation of a condenser cooling fan according to the ambient temperature of the condenser to maintain the refrigerant that passes through the interior of the condenser at a certain temperature or higher.

Abstract: A method, programmed medium and system are provided for altering the airflow through an electronic device such as a laptop computer in response to overheating, and feedback about the state of use of a laptop computer. In an exemplary embodiment, a laptop case is constructed such that it has an alternate opening for each intake and/or exhaust port. The primary intake and/or exhaust port is located such that it does not interfere with the user while the laptop is being operated normally. When it is detected that an intake and/or exhaust port is potentially blocked, it is determined whether or not the laptop is actively being used. If the laptop is not being used when an overheated condition is detected, a predetermined action is taken to change the air input/output air flow through an alternate exhaust path.

Abstract: An energy-reducing method and apparatus for retrofitting a constant volume HVAC system, with or without an economizer, that provides heating, cooling, and ventilation to occupants within a building space. The present invention includes the introduction of a programmable logic controller and variable frequency drive (VFD) that takes control of the existing fan, heating, cooling, and optional economizer operation. The controller is programmed for the reduction of fan speed in the heating and cooling modes. The reduction of the fan speed in the ventilation mode when the 100% operation is not needed saves significant energy of the existing constant volume HVAC system where the fan motor is designed to run 100% of the time. The fan speed may be further reduced upon a reduction in sensed occupancy levels of the space, such as with a CO2 sensor. Additionally, the fan speed may be reduced in the heating and/or cooling mode to further reduce energy consumption.

Abstract: Disclosed is an apparatus and a method for controlling a driving of a fan motor for a refrigerator. In a normal driving mode that a temperature of the inside of the refrigerator is higher than a predetermined temperature, the fan motor is driven in a normal speed, and in a waiting mode that the temperature of the inside of the refrigerator is lower than the predetermined temperature, the fan motor is driven in a driving speed very lower than that of the normal driving mode, without stopping of the fan motor, accordingly it is capable of preventing moisture introduced into the fan motor from being frozen, thereby preventing the fan motor from being locked.

Abstract: In an air-conditioning apparatus including a refrigerant circulating circuit A and a heat medium circulating circuit B that performs passing of heat to and from the refrigerant circulating circuit A, the heat medium circulating circuit is a closed circuit, the maximum pump head Pp of a pump of the heat medium circulating circuit is 150 kPa or more, and a pressure near at least a suction side of the pump is set to a charged pressure that is maintained equal to or higher than the atmospheric pressure during operation of the pump.