A heat pump cools in summer and moves outdoor heat indoors in winter, which suits Atlanta's long cooling seasons and mild winters. Periodic defrost cycles with steam are normal. Constant auxiliary heat in mild weather, heavy ice that doesn't clear, or warm air in cool mode point to a problem a licensed technician should check.
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Heat pumps are common across Metro Atlanta, and for good reason. A heat pump is an air conditioner that can also run in reverse, moving heat from the outdoor air into your home in winter. In a climate with long cooling seasons and relatively mild winters, one system handles both jobs efficiently.
How a heat pump works in Atlanta's climate
Even on a cold day there's heat in the outdoor air, and a heat pump moves it indoors rather than burning fuel to create it. That makes heat pumps an efficient way to heat during typical Atlanta winter weather. On the coldest nights, many systems switch on backup electric heat strips (often labeled "auxiliary" or "emergency" heat) to keep up, which costs more to run. Cold-climate heat pumps can keep working efficiently at lower temperatures, and dual-fuel systems pair a heat pump with a gas furnace that takes over when it gets very cold.
What's normal and what isn't
- Normal: in winter, the outdoor unit periodically goes into a defrost cycle. The fan may stop, you may hear a whoosh, and you may see steam rising. This usually lasts a few minutes.
- Normal: air from the vents in heat mode feels warm but not hot. Heat pumps deliver lower-temperature air for longer periods than a gas furnace.
- Not normal: the outdoor unit stays encased in ice for hours, or ice builds on the top and sides between defrost cycles.
- Not normal: the thermostat shows auxiliary heat running constantly in mild weather. That can mean the heat pump itself isn't doing its job, and your power bill will show it.
- Not normal: cold air in heat mode or warm air in cool mode, which can point to a reversing valve, refrigerant, or control problem.
Thermostat tips
Use a thermostat designed for heat pumps, and avoid big nighttime setbacks in winter. A large jump back up in the morning can trigger the more expensive backup heat. Smaller, steady adjustments are usually more economical.
Efficiency ratings
Heat pumps carry two ratings: SEER2 for cooling and HSPF2 for heating. Since 2023, new split-system heat pumps must meet at least 14.3 SEER2 and 7.5 HSPF2 under federal standards. Higher ratings mean lower operating costs, especially in a home that runs the system most of the year. Variable-speed (inverter) models can also do a better job of controlling humidity in summer because they run longer at lower speeds.
Ductless mini-splits
Ductless mini-split heat pumps are a practical option for additions, converted garages, bonus rooms, older homes without ducts, and rooms that never seem to keep up. Each indoor head is controlled separately, so you condition only the spaces you use.
Whether you need a repair or are considering a new heat pump, request an HVAC contractor who works on heat pumps in your area.
Frequently asked questions
Is a heat pump a good choice in Atlanta?
Heat pumps are common in Metro Atlanta because they heat efficiently in typical winter weather and provide cooling all summer. On the coldest nights they may rely on backup electric heat, or you can pair one with a gas furnace in a dual-fuel setup.
Why is steam coming off my heat pump in winter?
That's usually the defrost cycle melting frost off the outdoor coil. It's normal and typically lasts a few minutes. If the unit stays coated in ice for hours, call for service.
What does emergency heat mean on my thermostat?
Emergency heat runs only the backup heat source, usually electric strips, without the heat pump. It's meant for when the heat pump has failed. It works but costs more to run, so call for service rather than leaving it on.