What Is a Heat Pump? A Plain-English Guide
A heat pump is an electric system that heats and cools by moving heat, not burning fuel. See how it works, the types, costs and if it fits your home.
A heat pump is an electric heating and cooling system that moves heat instead of burning fuel to create it. In summer it pulls heat out of your house (working like an air conditioner); in winter it reverses and pulls heat from the outdoor air, or the ground, and delivers it inside. Because it moves existing heat rather than generating it, a well-matched unit can deliver two to four units of heat for every unit of electricity it draws, measured as its COP.
The one-sentence version
One machine replaces both your furnace and your air conditioner, runs on electricity, and heats by relocating heat rather than making it. That is the whole idea. Everything else, the ratings, the sizing, the price ranges, comes down to how well a given unit does that job in your specific climate and house.
The name confuses people because “pump” suggests water and “heat” suggests it only heats. In reality it pumps heat, the way a refrigerator pumps heat out of the food compartment and into your kitchen. A heat pump does the same trick at the scale of a whole house, and it can run the cycle in either direction.
A heat pump does not make heat; it moves heat that already exists, which is why it can be several times more efficient than a furnace or electric baseboard.
How it actually moves heat
The system uses a refrigerant that boils at a very low temperature. Even cold winter air holds usable heat, and the refrigerant absorbs it, gets compressed until it is hot, and releases that heat inside your home. A reversing valve flips the flow so the same hardware cools in summer. If you want the full walk-through, we cover it step by step in how heat pumps work.
Two pieces of outdoor and indoor hardware do the work. The condenser sits outside, and an indoor air handler or a wall-mounted head distributes the conditioned air. In freezing weather the outdoor coil can frost over, so the unit briefly runs a defrost cycle, which is normal and short.
Types of heat pump
Most homes are choosing among a few families. The right one depends on whether you have ductwork, how cold your winters get, and your budget.
| Type | How it fits | Typical installed cost |
|---|---|---|
| Ducted central air-source | Reuses or adds ductwork; whole-home | ~$8,000 to $14,000 common |
| Ductless mini-split | Wall heads per room, no ducts | ~$3,500 to $5,500 per zone |
| Geothermal (ground-source) | Buried loop field; highest efficiency | ~$18,000 to $45,000+ |
| Heat pump water heater | Heats domestic hot water only | ~$1,500 to $3,500 |
* Ranges vary widely by size, efficiency tier, region, and site conditions. Get itemized quotes before you budget.
An air-source heat pump pulls heat from outdoor air and is by far the most common and affordable choice. A geothermal heat pump pulls from the more stable temperature of the ground, which costs much more up front but runs cheaper. If your home has no ducts, a mini split heat pump is usually the practical answer.
Efficiency: the ratings that matter
Post-2023 systems are rated with updated test standards. You will see three numbers on the label, and it helps to know what each one measures.
- SEER2 rates cooling efficiency. Higher means cheaper summers.
- HSPF2 rates heating efficiency over the season.
- COP is the instantaneous physics ratio of heat out to electricity in, usually between 2 and 4.
Chasing the very highest ratings is not always worth the price jump; the payback depends on your electricity rates and how many hours the system runs. We break the numbers down in heat pump efficiency, SEER2 and HSPF2. A federal 25C tax credit of 30 percent of project cost, up to $2,000 a year, applies to units that meet the ENERGY STAR efficiency tier, which is one reason the ratings matter beyond the utility bill.
Do they work when it gets cold?
Yes, and modern cold-climate models are the reason this question has changed. ENERGY STAR Cold Climate units hold most of their capacity down to around 5F and keep producing usable heat well below zero. Below the point where the heat pump alone cannot keep up, a backup kicks in.
That backup is either electric resistance strips or, in a dual fuel heat pump, a gas furnace. This is the auxiliary heat your thermostat reports on the coldest mornings. The separate “emergency heat” setting is a manual override that locks the system into backup only. If your winters are severe, read do heat pumps work in cold climates before you buy.
Sizing, in plain terms
Capacity is measured in tons, where one ton equals 12,000 BTU per hour. A rough guide is 20 to 30 BTU per square foot, but that varies enormously with climate, insulation, windows, and air sealing. The honest answer is that a Manual J calculation is the only reliable way to size a system, and any installer who skips it is guessing.
Our full guide, what size heat pump do I need, walks through the tonnage math and the traps that lead to oversizing.
What it costs and what you can get back
A whole-home ducted system commonly lands around $8,000 to $14,000 installed, with the full range running from about $6,000 to $18,000 depending on size, efficiency, and ductwork. Two programs can lower that. The federal 25C tax credit returns 30 percent of the project up to $2,000 a year for qualifying equipment, claimed on IRS Form 5695; it is nonrefundable, so it only helps if you owe federal tax. Separately, income-qualified IRA rebates (the HEEHRA/HEAR program) can cover up to $8,000 toward a heat pump where available, but the program is state-administered and rolling out unevenly, so check your state program before you count on it.
For the full picture see heat pump cost and heat pump tax credit and rebates. If you are weighing a heat pump against keeping gas heat, heat pump vs furnace compares the running costs directly.
Is a heat pump right for your home?
For most US homes the answer is increasingly yes, especially if you are replacing an old air conditioner anyway and can fold the heating upgrade into one purchase. It fits best when your ducts are in decent shape or you choose ductless, when your electricity rates are reasonable, and when you pick a cold-climate model matched to your winters. It makes less sense if you have very cheap natural gas and a brutal climate, where a dual-fuel setup often wins.
The single biggest variable is the quality of the install and the sizing, not the brand on the box. Start with a Manual J, get itemized quotes, and read them carefully so you are not oversold. When you are ready to buy, how to read heat pump quotes and the 2026 heat pump guide will keep you grounded.
Frequently asked questions
What is a heat pump in simple terms?
It is an electric machine that heats and cools your home by moving heat instead of creating it. In winter it pulls heat from outside and brings it in; in summer it reverses and removes heat, working like an air conditioner.
Is a heat pump the same as an electric heater?
No. A plain electric heater turns electricity directly into heat at roughly one to one. A heat pump moves existing heat, so it can deliver two to four units of heat per unit of electricity, which makes it far cheaper to run.
Does a heat pump both heat and cool?
Yes. A reversing valve lets one system do both jobs, replacing a separate furnace and air conditioner. That dual function is the main thing that sets it apart from a standard AC unit.
Do heat pumps work in cold weather?
Modern cold-climate models hold most of their capacity to around 5F and keep working below zero. On the coldest days backup heat, either electric strips or a gas furnace in a dual-fuel setup, fills the gap.
How much does a heat pump cost?
A whole-home ducted system commonly runs about $8,000 to $14,000 installed, with the wider range from roughly $6,000 to $18,000. Ductless mini-splits run about $3,500 to $5,500 per zone, and geothermal is much higher.
Are there tax credits or rebates for heat pumps?
The federal 25C credit returns 30 percent of the project up to $2,000 a year for qualifying units, claimed on IRS Form 5695. Income-qualified state rebates of up to $8,000 exist where available, so check your state program.