What is a heat pump?
A heat pump is a single system that both heats and cools your home. The name is a little misleading: it doesn't create heat the way a furnace burns gas or a space heater glows. Instead, it moves heat from one place to another using refrigerant, a compressor, and two coils. In summer it moves heat out of your house; in winter it moves heat into your house. If you've ever felt warm air behind your refrigerator, you've felt a heat pump at work — your fridge moves heat out of the food compartment the very same way.
How does a heat pump move heat?
It runs a continuous refrigeration cycle. Refrigerant circulates between the indoor and outdoor coils, changing between liquid and gas to absorb and release heat:
- Absorb. Refrigerant in the outdoor coil soaks up heat from the outside air — yes, even cold air holds heat.
- Compress. The compressor squeezes that refrigerant, which raises its temperature sharply.
- Release. The now-hot refrigerant flows to the indoor coil and releases its heat into the air your blower pushes through the house.
- Expand & repeat. The refrigerant expands, cools back down, and heads outside to absorb more heat.
In cooling mode, that whole process simply runs in reverse — heat is pulled from your indoor air and dumped outside.
How does one system both heat and cool?
The clever part is a component called the reversing valve. It changes the direction the refrigerant flows, which swaps the jobs of the two coils. That's the only real difference between "heating" and "cooling" for a heat pump.
| Mode | Outdoor coil | Indoor coil | Result |
|---|---|---|---|
| Heating (winter) | Absorbs outdoor heat | Releases heat indoors | Warm air inside |
| Cooling (summer) | Releases heat outdoors | Absorbs indoor heat | Cool air inside |
Because one machine does both jobs, a heat pump replaces a separate air conditioner and furnace.
How efficient is a heat pump?
Moving heat takes far less energy than making it, which is why heat pumps are so efficient. You'll see a few ratings:
- HSPF2 measures heating efficiency over a season — higher is better.
- SEER2 measures cooling efficiency — also higher-is-better. (See what SEER2 means in Kentucky.)
- COP describes how much heat you get per unit of electricity at a given moment; a COP of 3 means three units of heat for one unit of power.
Unfamiliar terms? Our HVAC glossary defines SEER2, HSPF2, COP, tonnage, and more in plain language.
When a heat pump shines (and its limits)
A heat pump is a strong fit for Kentucky's moderate, humid-subtropical climate because it heats efficiently for most of the season and cools all summer in one system. Its main limit is the coldest weather: efficiency drops as the temperature falls, so systems here include backup heat for hard cold snaps. We cover that honestly in do heat pumps work in Kentucky winters? and in dual-fuel heating, which adds a gas furnace for the coldest days.
Is a heat pump right for your home?
Whether a heat pump beats a traditional setup depends on your home, ductwork, and energy prices — compare them in our AC vs. heat pump guide, and see real numbers in the heat pump cost guide. DuctPros is a Daikin Authorized Dealer serving Somerset and the Lake Cumberland area, with 50+ years of combined experience, a Kentucky license (#HM04747), and EPA Section 608-certified technicians. Ready to explore? Request a free estimate, ask about financing through GoodLeap, or call (606) 492-9767.