A refrigerant pump is part of a heating, ventilating, and air conditioning (HVAC) unit. An HVAC unit is responsible for heating and cooling the interior of buildings. The unit may also filter fresh air drawn in from the outside and expel indoor air to reduce contamination levels. Other refrigeration equipment, such as refrigerators and freezers, also use a refrigerant pump.
An air conditioning system works by cooling air that is pumped inside and circulated. A refrigerant pump is part of that system. The liquid refrigerant is located in the bottom of the evaporator where it flows up and over a set of cooling coils. As the liquid flows through this cooling loop, it absorbs heat and starts to boil. Once it boils, it turns into vapor known as Freon™.
The vapor then is pulled into a piece of equipment known as a compressor via suction pressure on the inlet lines. The refrigerant pressure builds up in the compressor as the refrigerant vapor also absorbs heat from the mechanical movements inside the refrigerant pump and other moving parts. This flow of vapor becomes extremely hot which also increase the pressure inside the compressor. As the pressure builds, the compressor discharges the vapor through and outlet line which moves it to the condenser.
The condenser is able to remove the built-up heat and convert the vapor back into a liquid. It does this by blowing the hot air outside and retaining the liquid by moving it to the expansion device. The expansion device, known as a thermostatic expansion valve (TEV), regulates the temperature and pressure in which the liquid refrigerant is returned to the refrigerant pump. There is a sensor bulb within the TEV that monitors the temperature.
Using a suction line, the liquid flows back into the refrigerant pump to start the process again. The refrigerant pump then pushes the liquid through the evaporator. This allows cool air to blow into the indoor space using a blower fan that is attached to the back of the evaporator.
The refrigerant pump on refrigerators and freezers work in much the same manner. Coils on the back of the system pass liquid refrigerant through them, which in turn heats the liquid and turns it into vapor. A compressor builds pressure which is released through the expansion valve. The cooling turns the vapor back into a liquid and the process begins again. This continuous loop of heating and cooling is what keeps cold the food that is inside.