Abstract: A temperature control system according to one embodiment includes: a refrigeration apparatus in which a compressor, a condenser, an expansion valve and an evaporator are connected in this order for circulating a refrigerant; a fluid circulation apparatus that causes a fluid to be heat-exchanged in the evaporator, then sends the fluid to a temperature control object, and again causes the fluid having passed through the temperature control object to be heat-exchanged in the evaporator, the fluid circulation apparatus having a heater at a position downstream of the temperature control object and upstream of the evaporator; and a control apparatus.

Abstract: An air conditioner includes a blower unit to blow air at a predetermined amount, a cooling unit arranged downstream of the blower unit in an air flowing direction, a compressor which is operated at a variable operating frequency so that a revolving speed thereof is adjustable, a condenser, and a cooling coil connected in this order by pipes to circulate a heating medium to cool blown air with a heating unit arranged on a downstream side of the cooling unit in the air flowing direction in which the blown air is heated by a heater, and a control unit controls the operating frequency of the compressor and includes a compressor control part which adjusts the revolving speed of the compressor such that the operating frequency of the compressor is decreased by a predetermined frequency when an output of the heating unit exceeds a first threshold value.

Abstract: Disclosed herein are systems and methods for providing hot air or hot dehumidified air to a facility using an energy recovery high efficiency dehumidification system. The energy recovery high efficiency dehumidification system can include an air filter bank that receives air from a first inlet source, a supply fan that causes the air to flow from the first inlet source, a cooling coil configured to cool and reduce a relative humidity of the air that passes over the cooling coil, a cooling recovery coil coupled with the cooling coil and configured to heat the cooled air to generate cooled dehumidified reheated air in a cooling recovery coil plenum, an equipment room configured to surround mechanical and electrical equipment and further heat received cooled dehumidified reheated air, and a heat rejection coil that rejects heat from one or more components of the mechanical and electrical equipment to further heat the air.

Abstract: A heating, ventilation, and/or air conditioning (HVAC) unit includes a refrigerant circuit including a reheat coil and a condenser system, a first valve disposed along the refrigerant circuit and configured to modulate refrigerant flow to the reheat coil and to the condenser system, and a second valve disposed along the refrigerant circuit downstream of the first valve relative to a direction of the refrigerant flow through the refrigerant circuit. The condenser system includes a first condenser coil and a second condenser coil, and the second valve is configured to be actuated to control refrigerant flow to the second condenser coil.

Abstract: A controller, a water source heat pump and a computer useable medium are disclosed herein. In one embodiment the controller includes: (1) an interface configured to receive operating data and monitoring data from the water source heat pump and transmit control signals to components of thereof and (2) a processor configured to respond to the operating data or the monitoring data by operating at least one motor-operated valve of the water source heat pump via a control signal.

Abstract: A reheat system of an air conditioning unit includes a bypass line that fluidly couples an outlet of a reheat coil to an input end of a metering device. Further, the reheat system includes a reheat exit line that fluidly couples the outlet of the reheat coil to an input of a condenser. A bypass valve is disposed in the bypass line and a reheat valve is disposed in the reheat exit line. A controller is configured to control the bypass valve and the reheat valve such that a refrigerant from the outlet of the reheat coil is routed to the metering device via the bypass line when an ambient temperature is greater than or equal to a cut-off temperature value that is indicative of a high ambient temperature condition at which the condenser begins operating as an evaporator.

Abstract: This document describes a high efficiency dehumidification system (HEDS) and method of operating the same. The HEDS systems and physical implementations can include a variety of equipment, such as fans, fluid-conveying coils, tubing and pipes, heat transfer coils, vents, louvers, dampers, valves, fluid chillers, fluid heaters, and/or the like. Any of the implementations described herein can also include controls and logic, responsive to one or more sensors or other input devices, for controlling the equipment for each implementation described herein. The HEDS system utilizes heat transfer between the fluid within the fluid-conveying coils and air passing over the coils to convert humid air into dehumidified air.

Abstract: Systems for atmospheric water generation are disclosed. An illustrative system may comprise an atmospheric water generator, and a wireless communications device communicatively coupled to the atmospheric water generator. The wireless communications device may be configured to receive and display status information associated with the atmospheric water generator, and to provide operating instructions to the atmospheric water generator. The wireless communications device may be further configured to display an outside temperature, an outdoor humidity, a water level, an indoor temperature, an indoor humidity, and a dew point. The wireless communications device may be further configured to receive control instructions, and wherein the wireless communications device is further configured to communicate the control instructions to the atmospheric water generator.

Abstract: The present disclosure relates to a climate management system having an outdoor coil of a refrigerant circuit, a first indoor coil of the refrigerant circuit, and a second indoor coil of the refrigerant circuit disposed downstream of the first indoor coil with respect to a flow of air directed across the first indoor coil and the second indoor coil. The climate management system is configured to, in a cooling mode, direct refrigerant flow in a first direction through the outdoor coil, direct refrigerant flow through the first indoor coil, and restrict refrigerant flow from the second indoor coil. The climate management system is also configured to, in a heating mode, direct refrigerant flow in a second direction through the outdoor coil, direct refrigerant flow through the second indoor coil, and restrict refrigerant flow from the first indoor coil. The second direction is opposite the first direction.

Abstract: The present disclosure relates to a heating, ventilation, and/or air conditioning (HVAC) system that has a first circuit and a second circuit that each have a compressor and a condenser, a conduit extending from the second circuit downstream of the condenser to the first circuit upstream of the compressor, a valve along the conduit that may manage flow therethrough, and a controller that may operate the HVAC system in a first mode such that each circuit separately circulates the refrigerant in each circuit and transition to a second mode such that refrigerant-sharing occurs between the circuits. In response to a request to transition from the second mode to the first mode, the controller may determine an amount of refrigerant subcooling, compare the amount to a threshold value associated with the first mode, and instruct opening of the valve upon a determination that the amount is less than the threshold value.

Abstract: An air conditioning system and a method of operating the same to improve system performance is provided. The air conditioning system includes an outdoor heat exchanger, an indoor heat exchanger, and a reheat heat exchanger. A reheat temperature sensor positioned proximate an upstream end of the reheat heat exchanger in a cooling mode for measuring a reheat coil saturation temperature. A controller adjusts at least one operating parameter, such as a compressor or fan speed, in response to the reheat coil saturation temperature and/or one of an outdoor coil vapor temperature, an indoor coil vapor temperature, an outdoor coil saturation temperature, and an indoor coil saturation temperature.

Abstract: An air distribution apparatus that serves as a single sensing device for both lighting, LiFi, and HVAC functions that are operable on a single platform by building automation systems. The building automation system may be controllable by a single software system or network accessible locally on site or remotely off site. The air distribution apparatus can operate in a single zone or coupled with multiple like apparatuses for multi-zone operation. It is a high turndown, self-balancing system which allows for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The air distribution apparatus includes multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

Abstract: An air conditioner includes: a cooling unit having a compressor operated at a variable operating frequency to adjust a revolving speed thereof, a condenser, an expansion valve and a cooling coil; and a heating unit for causing the heating medium flowing from the compressor toward the condenser to diverge, and to return to flow into the condenser, through a heating coil and a thermal dose adjusting valve disposed on the downstream side thereof; so as to control a temperature of air by the cooling and heating coils. When an opening manipulated variable of the thermal dose adjusting valve exceeds a first threshold value over a period of time, an operating frequency of the compressor is decreased, and when the opening manipulated variable of the thermal dose adjusting valve falls below a smaller, second threshold value, over the said period of time, the operating frequency of the compressor is increased.

Abstract: A method of controlling fluid flow through a heating, ventilating, air conditioning, and refrigeration (HVAC-R) system includes measuring temperature and pressure at an outlet of an evaporator of the HVAC-R system, wherein the evaporator is in fluid communication with a compressor, a condenser, an expansion device between the evaporator and the condenser, and a flow control valve between the compressor and the condenser, and measuring a sub-cooling temperature at an outlet of the condenser. The measured evaporator temperature and pressure data is sent to a first superheat processor, and the measured sub-cooling temperature data is send to a second superheat processor. A control signal to the expansion device from the first superheat processor and a control signal to the flow control valve from the second superheat processor are then simultaneously sent.

Abstract: A data center includes heat producing components and an air handling system that provides reduced relative humidity air to cool the heat producing components. The air handling system includes a thermal storage unit that removes thermal energy from incoming air under a given set of ambient air conditions and releases thermal energy into incoming air under another set of ambient air conditions. Under the given set of ambient air conditions, the thermal storage unit cools the incoming air and causes water vapor to condense out of the incoming air. Under the other set of ambient air conditions, the thermal storage unit releases thermal energy into the incoming air, thus heating the incoming air.

Abstract: The invention relates to a method for cooling or heating a fluid or a body by means of a vapour compression circuit containing a heat transfer fluid, said circuit being at least partially contained in an enclosure, and the relative humidity of the air in the enclosure being less than or equal to a threshold value H1 which is less than 50%, the flammability of the heat transfer fluid at relative humidity H1 being less than the flammability of the heat transfer fluid at 50% relative humidity. The invention also relates to a cooling or heating installation suited to the implementation of this method. The invention also relates to a method of protection against the risks of fire or explosion in an enclosure containing at least partially a vapour compression circuit containing a heat transfer fluid, as well as a method for reducing the GWP of a transfer fluid. The invention also relates to heat transfer fluids suited to the implementation of the above methods.

Abstract: A cooling system for an aircraft includes an air intake, an expansion device, and an evaporator. A first heat exchanger receives air passing into the air intake when the aircraft is operating at elevation, and receives the refrigerant from a first compressor at a first pressure. A second compressor receives the refrigerant from the first heat exchanger and compresses the refrigerant to a second pressure that is greater than the first pressure. A second heat exchanger receives the refrigerant from the second compressor. The first and second compressors are configured the first and second compressors are configured to operate at pressures that avoid temperature differences between the refrigerant and the air within each of the first and second heat exchangers below a set restriction.

Abstract: A system and method of controlling a multiple condenser air conditioning system that provides for efficient regulation of air temperature. The refrigeration system includes one or more valves whose operation is preferably controlled by programmable control logic to regulate flow through the refrigerant condenser(s) and sequentially control compressor discharge pressure and temperature in response to demands for heating or reheating of a supply air flow.

Abstract: An outdoor device for an air conditioner is provided that may include a compressor, a flow switch provided at an outlet-side of the compressor to switch a flow direction of a refrigerant according to a cooling operation or a heating operation, and an outdoor heat exchanger connected to the flow switch.

Abstract: The present invention relates to a multi-mode thermal management assembly with a selectable coolant flow path, and in particular to an assembly that selectably removes latent and/or sensible heat. Coolant (working fluid) is routed through openings in the bottom of the thermal management assembly. The assembly can have two heat exchangers (coolers), each having side-by-side vertical paths whereby coolant both enters and exits from the heat exchangers at their respective bottoms. Plumbing is provided that can be selected to route coolant for one of the user selected cooling modes. Valves allow the user to select at least between a combination mode (latent cooling with sensible reheat) and a sensible only cooling mode. In the combination mode, the latent heat exchanger cools and dehumidifies, and the sensible heat exchanger partially reheats the air while requiring no additional work to be done on the system by external power consuming devices.

Abstract: A space conditioning system includes a hot gas reheat section and one or more modulating valves to direct a percentage of refrigerant flow to the hot gas reheat section. The hot gas reheat section includes multiple refrigerant circuits arranged in parallel. A control valve is used to allow the refrigerant to flow through selected ones of the multiple refrigerant circuits in response to the percentage of refrigerant flow directed to the hot gas reheat section, thereby varying the internal volume of the hot gas reheat section available to the refrigerant. Refrigerant charge hold-up within the hot gas reheat section can thereby be minimized.

Abstract: In various implementations, an air conditioning system may automatically adjust an amount of refrigerant using an accumulator. The air conditioning system may operate in at least two operation modes including a cooling operation and a reheat operation. The amount of refrigerant allowed to flow to a condenser of the system may be based at least partially on the operating mode of the air conditioning system.

Abstract: An air conditioning system, an outdoor apparatus of an air conditioning system and a method for controlling an air conditioning system are provided. The air conditioning system includes: an indoor apparatus and an outdoor apparatus. The outdoor apparatus includes a variable-frequency compressor and a controller configured to perform a variable-frequency control on the variable-frequency compressor according to operation parameters of the variable-frequency compressor and independent from the indoor apparatus.

Abstract: A method for controlling an air conditioning system, an outdoor apparatus of an air conditioning system and an air conditioning system are provided. The method includes: obtaining a working mode of the air conditioning system and starting a variable-frequency compressor in an outdoor apparatus of the air conditioning system according to the working mode; obtaining a target refrigerant saturation temperature; performing a variable-frequency control on the variable-frequency compressor according to the target refrigerant saturation temperature; during the variable-frequency control, obtaining a working time of the variable-frequency compressor and a stop-start number of time of the variable-frequency compressor in a first predetermined period; and adjusting the target refrigerant saturation temperature according to the working time of the variable-frequency compressor and the stop-start number of time of the variable-frequency compressor in the first predetermined time.

Abstract: A building ventilator to provide a supply of air into a building comprises an external inlet port and a separate external outlet port and an internal inlet port and a separate internal outlet port to allow respective airstreams to flow into and out of the ventilator respectively at an exterior and at an interior of the building; a heat exchanger mounted in the flow paths between the external and internal inlet and outlet ports. The ventilator is configured to drive an airflow from the external inlet port through the heat exchanger and out of the ventilator via the internal outlet port; and to drive an airflow from the internal inlet port through the heat exchanger and out of the ventilator via the external outlet port. The ventilator comprises a heating element mounted in the air flow path between the external inlet port and the heat exchanger.

Abstract: The invention relates to an arrangement for air-conditioning rooms and to a heat pump for use in such an arrangement. The arrangement comprises a central heating device, to which multiple lines containing a heat-exchanging fluid are connected. The arrangement additionally comprises multiple decentralized, electrically operated heat pump units, which are energetically connected to the central heating device via the mentioned lines. The respective heat pump unit has a plurality of heat pump modules, which absorb thermal energy from the fluid for heating or deliver thermal energy to the fluid for cooling and/or dehumidifying. The mentioned heat pump modules preferably comprise Peltier elements acting as heat pump elements.

Abstract: A cross-flow heat exchanger, method of making a cross-flow heat exchanger, and a dehumidifier are provided. The cross-flow heat exchanger has an axial flow path extending through the heat exchanger from an inlet to an outlet and a transverse flow path oriented transversely to the axial flow path and extending through the heat exchanger from an inlet to an outlet. The transverse flow path is adjacent to and separate from the axial flow path. The surface area of the inlet of the axial flow path is less than the surface area of the outlet of the axial flow path. In a preferred embodiment, the heat exchanger has an exterior shape that is trapezoidal.

Abstract: An air conditioning system comprising an air mover for circulating air to a space; a vapor compression circuit including a compressor, a condenser, and an expansion device; an evaporator; an air-reheat heat exchanger; and a control system. In one embodiment, the evaporator receives refrigerant from the vapor compression circuit and provides a cooled stream of air to the space. The air-reheat heat exchanger is positioned to receive the cooled stream of air. In one embodiment, the vapor compression circuit, the evaporator, and the air-reheat heat exchanger are operable in combination to provide a plurality of modes of operation. In a preferred embodiment, the control system is configured to compute a Sensible cooling-to-Total cooling (S/T) process ratio and to control an operation of at least one of the vapor compression circuit, the evaporator, and the air-reheat heat exchanger. A method of manufacturing the air conditioning system is also provided.

Abstract: The present disclosure is directed to a single compressor HVAC system with hot gas reheat. The system includes a single compressor, a pair of condensers, a reheat heat exchanger, an evaporator, and an expansion device. Within the system, the refrigerant exiting the compressor is separated into two portions. In the cooling mode, the first and second portions of the refrigerant are directed from the compressor through the two condensers in parallel. In the reheat mode, the first portion of the refrigerant is directed through the first condenser, while the second portion of the refrigerant is directed through the reheat heat exchanger. The system also may include a head pressure control device that is designed to maintain the compressor discharge pressure within a desired range by adjusting the condenser fan speed.

Abstract: A refrigerator includes a cabinet to define an outer appearance of the refrigerator and having a storage chamber therein; and a water filter device installed in the storage chamber, to purify water supplied from an external water supply source. The water filter device includes a filter unit to purify the water supplied from the water supply source, a storage tank unit to store the water purified through the filter unit, a case to accommodate the filter unit and the storage tank unit, a filter head assembly, and a water filter assembly separably coupled to the filter head assembly.

Abstract: An air conditioner includes a body installed at an outdoor space, and an air discharge tube to guide cold air discharged from the body to an indoor space. An evaporator and a condenser are installed in the body. The evaporator is disposed at a higher level than the condenser. Accordingly, it possible to transfer condensed water generated from the evaporator to the condenser by gravity.

Abstract: A heat pump-type hot water supply apparatus may be provided that includes: a refrigeration cycle circuit (including a compressor, an outdoor heat exchanger, expansion devices, and an indoor heat exchanger); a hot water supply heat exchanger connected to the refrigeration cycle circuit to use the first refrigerant discharged from the compressor for a hot water supply; a cascade heat exchanger connected to the refrigeration cycle circuit to allow the first refrigerant passing through the hot water supply heat exchanger to evaporate a second refrigerant and thereafter, to be condensed, expanded, and evaporated in the refrigeration cycle circuit; a heat storage compressor compressing the second refrigerant evaporated in the cascade heat exchanger, a heat storage tank to heat water using the second refrigerant compressed by the heat storage compressor, and a heat storage expansion device to expand the second refrigerant condensed in the heat storage tank.

Abstract: A stepped approach to cooling capacity control and the HGRH status logic to achieve the requisite control of humidity and temperature provided to an interior area or building space receiving conditioned air. The system includes at least two independent circuits, each circuit having at least one compressor. At least one of the independent circuits includes hot gas reheat hardware thereby providing HGRH capability. The logic provides an efficient method for maintaining both humidity and temperature in the interior area comfortable for occupants within limits as determined by psychrometrics. The system and method match the sensible capacity and latent capacity of the system match to the sensible and latent loads of the conditioned space.

Abstract: A refrigerated case (20) has a housing containing an interior volume (36) for storing items. Along an air flow path (510) through the case, a refrigerant-to-air heat exchanger (60) has an evaporator section (112) and a reheat section (114). A preconditioning section (110) may be upstream of the evaporator section (112) and the evaporator section is upstream of the reheat section (114). Along a refrigerant flow path (520), the reheat section (114) is downstream of the preconditioning section (110) (if any) and upstream of the evaporator section (112) and an expansion device (62) is between the reheat (114) and evaporator (112) sections.

Abstract: An electric re-heat dehumidification apparatus to dehumidify a conditioned space is provided and includes a conditioning unit to produce an output airstream including overcooled air to be provided to the conditioned space to overcool the conditioned space during the dehumidifying of the conditioned space, a resistive element disposed within an output airstream of the conditioning unit, which, when activated, heats the overcooled air of the output airstream and a controller, operably coupled to the resistive element, to activate the resistive element in accordance with information of the conditioning unit, the resistive element and a temperature of the conditioned space to limit the overcooling of the conditioned space.

Abstract: The invention relates to a cooling apparatus, especially for cryogenically preserving biological samples, comprising a duct (5) for delivering a coolant (3) to a cooling chamber (1), a heater (6) that has an adjustable first heating performance (P2) for heating the coolant (3) delivered to the cooling chamber (1), a first temperature sensor (8-10) for measuring the temperature (T2-T4) in the cooling chamber (1), a second temperature sensor (7) for measuring the temperature (T1) of the coolant (3) delivered to the cooling chamber (1), and a regulator (11) for regulating the temperature. Said regulator (11) is embodied as a multiple regulator which detects several temperatures (T1-T4) as control variables and/or adjusts several heating performances (P1, P2) as manipulated variables. The invention further relates to a corresponding operating method.

Abstract: In a hybrid-electric vehicle that includes a cabin, methods and systems are provided for modifying a first curve for engine coolant temperature (ECT) warm-up trajectory. The system includes a processor configured to execute software instructions, and a memory configured to store software instructions accessible by the processor. In one embodiment, the software instructions comprise an offset lookup table that is configured to generate, based on a calculated thermal power loss across a heater core and an ambient air temperature, an offset value for modifying the first curve for ECT warm-up trajectory to produce a desired curve for ECT warm-up trajectory that is offset from the first curve. The desired curve for ECT warm up trajectory is used to adjust temperature in the cabin so that fuel consumption can be reduced.

Abstract: Refrigerant systems are provided with selectively operable components that allow variation in the capacity provided by the refrigerant system to achieve desired temperature and humidity levels. A reheat circuit is provided and an economizer circuit may also be added to the system. Typically, the reheat and economizer functions each provide a step change in the humidity control. A compressor having a variable speed drive is utilized. By providing the reheat/economizer functions along with the variable speed compressor, continuously adjustable humidity control is achieved.

Abstract: A cooling recover system and method are disclosed. A fluid, such as water, is chilled and provided to a cooling coil to cool and dehumidify air passing over the cooling coil. The fluid is output from the cooling coil through an outlet, and at least a portion of the fluid from the outlet of the cooling coil is provided to an inlet of a heat transfer coil to reheat air passing over the heat transfer coil. The fluid is warmed as it passes through the cooling coil, which warmer temperature serves to reheat the air passing over the heat transfer coil.

Abstract: The present invention provides an energy efficient air conditioner that can provide a continuous supply of air at dew point that is several degrees Celsius below zero, without requiring a defrost cycle. The air conditioner in accordance to present invention comprises a plurality of cooling coils with interconnecting refrigerant piping, refrigeration circuit consisting of compressor and condenser coils, control circuit and one or more electric motor driven centrifugal fan. The present invention uses two cooling systems. The first cooling system having single coil cools the air to a temperature just above zero deg. C., say four deg. C. so that the second stage gets a steady supply of cold air. The second stage has two coils, each being half the size of the first stage coil, thus taking half the air from it so that all the air from stage 1 passes through stage 2. In operation, only one coil of the second stage is active arid chills the air going through it to say minus 14 Deg. C.

Abstract: A cooling recover system and method are disclosed. A fluid, such as water, is chilled and provided to a cooling coil to cool and dehumidify air passing over the cooling coil. The fluid is output from the cooling coil through an outlet, and at least a portion of the fluid from the outlet of the cooling coil is provided to an inlet of a heat transfer coil to reheat air passing over the heat transfer coil. The fluid is warmed as it passes through the cooling coil, which warmer temperature serves to reheat the air passing over the heat transfer coil.

Abstract: An ejector cycle system with a refrigerant cycle through which refrigerant flows includes an ejector disposed downstream of a radiator, a first evaporator located to evaporate refrigerant flowing out of the ejector, a branch passage branched from a branch portion between the radiator and a nozzle portion of the ejector and coupled to a refrigerant suction port of the ejector, a throttling unit located in the branch passage, and a second evaporator located downstream of the throttling unit to evaporate refrigerant. In the ejector cycle system, a variable throttling device is located in a refrigerant passage between a refrigerant outlet of the radiator and the branch portion to decompress the refrigerant flowing out of the radiator.

Abstract: A refrigerant system for cooling a comfort zone is selectively operable in a cooling-only mode and a reheat mode. The system operates in the cooling mode to meet sensible and latent cooling demands of a room or area in a building when the room temperature is appreciably above a target temperature. The reheat mode is for addressing the latent cooling or dehumidifying demand when the room temperature is near or below the target temperature. In some embodiments, a generally inactive condenser stores excess refrigerant during the reheat mode, thereby avoiding the need for a separate liquid refrigerant receiver. To maintain a desired level of subcooling in the reheat coil, refrigerant can be transferred accordingly between the inactive condenser and the reheat coil. In some embodiments, the system's evaporator and reheat coil can be connected in a series or parallel flow relationship.

Abstract: A refrigerant cycle is provided with a multi-port compressor or compressor stages connected in series, and multiple condensers. A single evaporator communicates with the plurality of condensers. At least one of the plurality of condensers receives fully compressed refrigerant while the other condensers receive refrigerant at intermediate pressure. A control can optionally direct refrigerant to the condensers to achieve desired system heat rejection characteristics and operating conditions. One or multiple reheat coils may be associated with the evaporator and are arranged either in series or in parallel to provide a desired dehumidification function and reheat stages. One or several of the intermediate pressure condensers may be utilized for the reheat function as well.

Abstract: A water-cooled air conditioning system using a regenerative condenser water circuit to reheat the supply air during a dehumidification mode. The air conditioning system may be any type of water-cooled system, including a water source heat pump or water-cooled air conditioner. The reheat circuit circulates water leaving the condenser through the reheat heat exchanger and then returns the water to the condenser inlet. Thus, the reheat circuit ensures that water leaving the condenser is warm enough to provide sufficient reheating for the supply air, regardless of the water source temperature. In addition, a modulation assembly controls the amount of water flowing through the reheat circuit, and thereby its temperature, so that the temperature of the reheated supply air can be maintained within a narrow range.

Abstract: An HVAC system including a compressor, a condenser and an evaporator arrangement connected in a closed refrigerant loop. The evaporator arrangement includes a plurality of refrigerant circuits. The evaporator arrangement also includes at least one distributor configured to distribute and deliver refrigerant to each circuit of the plurality of circuits. The plurality of circuits are arranged into a first and second set of circuits. The evaporator arrangement also includes a valve configured and disposed to isolate the first set of circuits from refrigerant flow from the condenser and provide flow of refrigerant from the compressor in a dehumidification operation of the HVAC system.

Abstract: A system and method for monitoring and controlling oil return to a compressor, characterized by monitoring and controlling oil level, oil temperature, and compressor outlet pressure, so as to determine whether the oil level is lower than a predetermined level threshold, whether the temperature in the lubricating oil box is lower than a predetermined temperature threshold, and whether the compressor outlet pressure exceeds a predetermined pressure threshold, so as to control the flow of lubricating oil returned to the oil box by controlling the valve opening of the oil return valve according to a non-segmentation principle or a segmentation principle, ensure sufficient lubricating oil in the oil box, and enhance efficiency of the system.

Abstract: A system and humidity control method is provided for a multi-stage cooling system having two or more refrigerant circuits that balances humidity control and cooling demand. Each refrigerant circuit includes a compressor, a vessel and an evaporator. A hot gas reheat circuit having a heat exchange coil is connected to one of the refrigerant circuits and is placed in fluid communication with the output airflow from the evaporator of that refrigerant circuit to provide additional dehumidification to the air when humidity control is requested. The hot gas reheat circuit bypasses the vessel of the refrigerant circuit during humidity control. Humidity control is performed during cooling operations and ventilation operations. During a first stage cooling operation using only one refrigerant circuit and having a low cooling demand, the request for humidity control activates the hot gas reheat circuit for dehumidification and activates a second refrigerant circuit to provide cooling capacity.

Abstract: In a drying system using a compression refrigeration system, a condenser is divided into a regulating condenser and a heating condenser. The regulating condenser is capable of regulating the amount of exhaust heat discharged to outside the system. The heating condenser produces moist air by feeding heat to an aqueous object to be dried placed in a processing vessel to evaporate the moisture in the object. Heat of condensation of steam is recovered by an evaporator as heat of a refrigerant, and the recovered heat is discharged in the heating condenser to use it for the vaporization of the moisture in the object, and excess heat is discharged by the regulating condenser to outside the system.

Abstract: A HVAC system and method for a vehicle is disclosed. The air conditioning portion of the HVAC system may be able to store and release refrigerant in charge bottle while operating in an air conditioning mode. The air conditioning portion of the HVAC system may be able to employ the refrigerant flowing through the evaporator to provide supplemental heat.