A method of operating a heating, ventilation, and air conditioning (HVAC) system includes monitoring a parameter of the HVAC system associated with a temperature of a refrigerant at a heat exchanger, determining if the HVAC system is in an operating condition associated with frost accumulation at the heat exchanger, and adjusting a flow rate of an airflow across the heat exchanger in response to determining that the HVAC system is in the operating condition associated with frost accumulation at the heat exchanger.

A thermoelectric assembly includes a thermoelectric module having a hot side and a cold side, where a heat sink is coupled with the hot side of the thermoelectric module and a cold sink is coupled with the cold side of the thermoelectric module. A metalized gasket is disposed between the heat sink and the cold sink and extends around a portion of the thermoelectric module. A vapor barrier may be attached to and cover an outer surface of the metalized gasket.

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

In an embodiment, a method of preventing evaporator coil freeze in a heating, ventilation and air conditioning (HVAC) system includes determining a reference saturated suction temperate (SST) via a sensor disposed in relation to an evaporator coil in the HVAC system, where the HVAC; system is operating in reheat dehumidification mode. The method also includes determining whether the reference SST is below a minimum SST threshold. The method also includes, responsive to a determination that the reference SST is below the minimum SST threshold, determining a decreased compressor speed. The method also includes modulating a variable-speed compressor in the HVAC system in correspondence to the decreased compressor speed.

An evaporator includes: an evaporator case that defines a food storage space therein; a cooling tube located at the evaporator case and filled with refrigerant; a foil heater attached to at least one surface of the evaporator case and configured to contact the evaporator case and to generate heat such that heat for defrosting is transferred to the evaporator case. A defrosting time is reduced in comparison to that of conventional natural defrosting, such that the freshness of food can be maintained, and the cooling efficiency, having been reduced by frost, is increased such that power consumption can be reduced. The foil heater is attached to a conventional roll-bond type evaporator case, and the present invention has an advantageous effect of facilitating the maintenance of the foil heater because of a structure in which the foil heater is attached to the evaporator case.

Methods for shortening the cycle time in each of the defrost, standby and cool modes of operation of a very low temperature refrigeration system. These methods can be used alone or in combination with one or more of each of the other techniques, including, for example, in a single very low temperature refrigeration system, to provide a fast total cycle of one, two or all three of the defrost, standby and cool modes.

In a heat pump cycle device, a flow passage switching portion includes a flow passage switching valve body configured to open and close a cooling side flow passage. A refrigerant circulation circuit includes a low-pressure flow passage through which a low-pressure refrigerant decompressed by a first decompressor flows toward a compressor in a heating mode, and a pre-evaporator flow passage provided between the flow passage switching valve body and a refrigerant inlet of an evaporator. The flow passage switching portion causes a pre-evaporator flow passage to communicate with the low-pressure flow passage while bypassing the evaporator when a refrigerant pressure in the low-pressure flow passage is lower than a refrigerant pressure in the pre-evaporator flow passage, in the heating mode.

The present invention discloses a method for preparing an evaporator for reducing water condensing capacity and an evaporator. The preparation method comprises steps of: step A: selecting fins; step B: stacking; step C: arranging tubes; and, step D: expanding tubes. In accordance with the present invention, the existing fins and devices can be used to produce an evaporator in which the distance between two adjacent fins satisfies the requirements of the freezing operation, ensuring the normal operation of an air conditioner when the refrigeration temperature is below 0° C.

A refrigerant cycle system includes: a first refrigerant circuit; a second refrigerant circuit independent of the first refrigerant circuit; a heat source-side unit that includes a first heat source-side heat exchange unit and a second heat source-side heat exchange unit; a first use-side unit that includes a first use-side heat exchanger; a first liquid refrigerant connection pipe and a first gas refrigerant connection pipe that connect the first use-side unit to the heat source-side unit; a second use-side unit that includes a second use-side heat exchanger; and a second liquid refrigerant connection pipe and a second gas refrigerant connection pipe that connect the second use-side unit to the heat source-side unit.

The present disclosure relates to the technical field of heat pumps, in particular to an air source CO.sub.2 heat pump system for preventing an evaporator from frosting by using heat of a heat regenerator. The air source CO.sub.2 heat pump system mainly includes an air source heat pump system, a regenerative heat exchange tank and a cooling pump. Through the regenerative heat exchange tank, on the one hand, the temperature drop of regenerative heat of the system is further increased and throttling loss is reduced; on the other hand, the heat generated by the regenerative temperature drop is configured for heat storage used for defrosting, and configured for overheating temperature rise.