The Language of Heat Pumps: Is It Foreign to You?

While some HVAC systems use separate appliances to heat and cool a home, heat pumps can provide both functions in the same system for year-round comfort. Learning a few of the terms associated with heat pumps can help you to understand how these functions work and how to recognize problems within your system if they arise.

• Refrigerant: This is a special formula that is used to transport heat by absorbing it from one side of the system and releasing it on the other. During the process, the refrigerant alternates between gas and liquid phases. Newer types of refrigerant work under higher pressures than older types, and are less bad for the environment.
• Coil: A set of usually copper tubes arranged in one or more loops with optional fins that are used to provide a large surface area for heat exchange. Refrigerant is pumped through a coil to either absorb heat from or release heat to the air.
• Evaporator: Refrigerant enters this coil as a liquid and absorbs heat from the air. The refrigerant begins to boil, turning into a gas, and is sent to the compressor.
• Accumulator: A device between the evaporator and compressor in some systems that stores any liquid which did not turn into a gas.
• Compressor: This device is a motor that compresses the vaporized refrigerant mechanically, pushing the refrigerant molecules together and raising their temperature through friction.
• Condenser: The refrigerant enters this coil after the compressor, releasing heat from the gas into the environment and returning the gas to liquid form.
• Expansion valve: As the refrigerant flows through this device, the pressure is reduced, which, in turn, lowers the temperature of the liquid. The refrigerant then returns to the evaporator to begin the cycle again.
• Reversing valve: This device reverses the flow of the heat pump, which allows it to either heat or cool the house. When switching from heating to cooling, the evaporator and condenser essentially reverse roles.
• Plenum: A compartment above or around the heat exchanger in which conditioned air gathers before being distributed throughout the house.

If you would like more information about heat pumps or other HVAC systems, feel free to contact us at Rinaldi’s Energy Solutions, serving Orlando and the Central Florida area since 1969.

Our goal is to help educate our customers in Orlando, Florida and surrounding areas about energy and home comfort issues (specific to HVAC systems).  For more information about heat pumps and other HVAC topics, download our free Home Comfort Resource guide.

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