The Heat Pump in Your Orlando Home: Its Cooling, Heating and Defrost Cycles

An air-source heat pump is a technological marvel capable of producing either heating or cooling for your Central Florida home, whichever is needed at the time. Both heat pump heating and heat pump cooling incorporate the same principles of heat transfer, with a reversing valve responsible for reversing the function from one to the other. In all, a heat pump has three cycles:

1. Heating cycle
2. Cooling cycle
3. Defrost cycle

The heating cycle is used when outdoor temperatures are cold and indoor heat is required. Heat transfer is a natural phenomenon, with warmth moving into cold areas to maintain thermal equilibrium. Outdoor copper coils filled with refrigerant are used to absorb heat existing in the outdoor air. The refrigerant is then compressed, heating it even more. It travels to a set of indoor copper coils where the heat is extracted and used to heat the indoor air, which is then blown by a fan into the air distribution ductwork. Because the refrigerant has been heated to a temperature greater than the indoor air, this heat readily transfers to the cooler air, seeking equilibrium, thereby heating your indoor living area.

The heat pump cooling cycle is the exact opposite of the heating cycle, whereby heat is absorbed by the inside coils, compressed and then sent to the outside coils where, because of the temperature increase in the refrigerant, the heat readily transfers to the cooler outdoor air. In the Orlando area, heat pump cooling is used most often, since outdoor temperatures here are warm most months.

The defrost cycle comes into play during heating operations when the outside temperature falls below freezing. As moisture in the air condenses and freezes on the outdoor coils, it reduces their ability to absorb heat. To defrost itself, the unit switches to cooling mode and the outdoor fan shuts itself off. This allows warm air absorbed from the home’s interior to heat the coil and melt any accumulated frost.

Rinaldi’s Air Conditioning Service has been serving our customers in Central Florida out of our Orlando offices for more than four decades. Contact us for information or assistance with any of your home’s air comfort or air quality needs.

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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