When shopping for a heat pump, you’re taking a trip into the world of heating and air conditioning engineering. A heat pump works like an air conditioner in the summer, and thanks to design technology, as a home heater in the winter. Heat pumps simply exchange heat from one place to another for both functions. The following terms will help you make the right choice:
- SEER and EER. The SEER, seasonal energy efficiency ratio, indicates the energy efficiency of a heat pump over the entire cooling season. The minimum allowed in new A/Cs and heat pumps is 13. The EER, energy efficiency ratio, shows how much electricity the heat pump uses to output cooling during the hottest days. It’s good to consider the EER for hot summer climates like ours if you’re shopping for a heat pump.
- Refrigerant. The refrigerant is the substance heat pumps use to transport heat out of the house when cooling and inside the house when heating. Sometimes it’s informally known by the brand name Freon.
- Reversing valve. Heat pumps use these valves to reverse the flow of refrigerant, depending on the season. Sometimes this valve starts the defrosting cycle in the winter if the outdoor coils freeze over.
- Condenser. This unit sits outdoors and exchanges the heat, winter and summer. The coils that contain the refrigerant run through it and either dispose of heat or pick it up, using a fan to pull air through the fins and coils.
- Compressor. The unit compresses the refrigerant for cooling and expands it for heating. It’s outside with the condensing unit in most systems.
- Expansion valve. This valve, along with the compressor, lets the refrigerant condense hotter outside, so the temperature it delivers indoors is cooler in hot weather.
- Air handler. The indoor air handler contains the motor for the fan that circulates the conditioned air through the ducts. Some heat pumps, called mini-splits, do not use ducts, but blow the air directly into the room. All air handlers have evaporator coils that the fan blows over, heating or cooling the air.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about shopping for a heat pump and other HVAC topics, download our free Home Comfort Resource guide.