A heat pump controller for use in a heat exchange system includes a computing device and a user interface coupled to the computing device. The computing device is configured to initiate a defrost cycle based on one of a plurality of user-selectable defrost modes, and the user interface is configured to display the user-selectable defrost modes and receive a user selection corresponding to one of the user-selectable defrost modes.

A refrigeration apparatus uses R32 as a refrigerant, and includes a compressor, a condenser, an expansion mechanism, an evaporator, an intermediate injection channel and a suction injection channel. The intermediate injection channel guides a part of the refrigerant flowing from the condenser toward the evaporator to the compressor, causing the refrigerant to merge with intermediate-pressure refrigerant of the compressor. The suction injection channel guides a part of the refrigerant flowing from the condenser toward the evaporator to the suction passage, causing the refrigerant to merge with low-pressure refrigerant sucked into the compressor.

A return air superheat degree test method for a multi-split system. A multi-split system comprises a re-cooling loop composed of a first heat exchanger (100) and a second heat exchanger (200), a first temperature sensor (11), a second temperature sensor (12) and a third temperature sensor (13). The return air superheat degree test method comprises the following steps: acquiring a first temperature value (T.sub.1) detected by the first temperature sensor (11), a second temperature value (T.sub.intermediate) detected by the second temperature sensor (12) and a third temperature value (T.sub.2) detected by the third temperature sensor (13); acquiring a minimum value between the first temperature value (T.sub.1) and the second temperature value (T.sub.intermediate), and acquiring a maximum value between the third temperature value (T.sub.2) and the second temperature value (T.sub.intermediate); and calculating a superheat degree according to the minimum value and the maximum value.

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. The control apparatus activates the heater to heat the fluid by the heater, when the fluid circulation apparatus has become in a no-load operation state or a no-load-operation transition operation state, wherein the no-load operation state is a state in which the fluid and the temperature control object do not heat-exchange, the no-load-operation transition operation state is a state that is in transition to the no-load operation state.

A method for killing pests in an affected area of a structure, comprises positioning a heat pump unit within an affected area of the structure, coupling a first end of an inlet hose to a faucet, and coupling a second end of the inlet hose to an inlet port of the heat pump unit. The inlet port supplies a flow of water received from the faucet to an evaporator component of the heat pump unit. The evaporator component transfers heat from the flow of water to a refrigerant and communicate the refrigerant to a condenser component of the heat pump unit. The condenser component generates heated air by transferring heat from the refrigerant fluid to air flowing through the condenser component. The heated air i emitted into the affected area in order to raise the temperature of the affected area to a target temperature greater than 120 degrees Fahrenheit.

A refrigerated merchandiser includes a case having a base and a canopy at least partially defining a product display area. One or more eutectic plates are positioned in the product display area. The eutectic plates include a fluid contained in a housing. A heat exchanger including a coil is positioned in the housing to cool the fluid. The coil has an inlet, an outlet spaced from the inlet, a first portion, and a second portion adjacent and in thermal communication with the first portion to define a tube-to-tube heat exchanger.

An exemplary heat pump includes: an accumulator that separates liquid refrigerant from gas refrigerant returning to a compressor; a refrigerant suction channel connecting the compressor to the accumulator; a refrigerant return channel that returns liquid refrigerant in the accumulator to the refrigerant suction channel; a first valve disposed on the refrigerant return channel; a temperature sensor that detects a temperature of refrigerant in the refrigerant suction channel; a second valve that reduces a pressure of a part of liquid refrigerant flowing between the first and second heat exchangers; a refrigerant evaporator that gasifies, by using waste heat of an engine, the liquid refrigerant whose pressure has been reduced; a gas refrigerant supply channel through which the gasified refrigerant is supplied to the accumulator; and a control device that, while the first valve is open, controls an opening of the second valve based on the temperature detected by the temperature sensor.

A defrost cycle time of an aircraft vapor cycle refrigeration system is adaptively controlled. A pressure of refrigerant at an inlet of a compressor of the vapor cycle refrigeration system is sensed. A defrost cycle of the vapor cycle refrigeration system is initiated in response to the sensed pressure being less than a threshold pressure. The defrost cycle is terminated upon expiration of the defrost cycle time. The defrost cycle time is based upon a time duration of the cooling cycle.

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.

A system for heating a building via refrigerant includes a coil temperature sensor, an ambient temperature sensor, and a controller. The controller includes a processing circuit configured to record a system operating parameter and a control step of a control process before performing a sacrificial defrost cycle. The processing circuit is configured to cause the system to perform the sacrificial defrost cycle and operate the system at predefined system operating parameters other than the recorded system operating parameters. The system is configured to cause the system to operate at the recorded system operating parameters and generate calibration data in response to the sacrificial defrost cycle ending. The processing circuit is configured to cause the control process to operate at the recorded control step and cause the system to perform a defrost cycle based on the calibration data, the coil temperature, and the ambient temperature.