A residential heating and cooling heat pump is a system that heats and cools your home. In winter, it moves heat from outdoors into your home. In summer, it reverses direction and moves heat from indoors outside, much like an air conditioner.
Heat Pumps at a Glance
| Function | What the heat pump does |
|---|---|
| Heating | Transfers heat from outdoor air or the ground into your home |
| Cooling | Transfers heat from inside your home to the outdoors |
| Main components | Outdoor unit, indoor air handler, refrigerant circuit and reversing valve |
| Common types | Ducted air-source, ductless mini-split and geothermal |
| Energy source | Electricity |
How Does a Heat Pump Heat a Home?
A heat pump extracts available heat from outdoor air, even in cold weather. The refrigerant and compressor raise the temperature of that heat before the indoor unit distributes it through ductwork or wall-mounted indoor units.
A heat pump transfers heat instead of generating heat by burning fuel. ENERGY STAR says certified air-source heat pumps can deliver up to three times the heat energy to a home for each unit of electrical energy they use, depending on the system and operating conditions.
How Does a Heat Pump Cool a Home?
In cooling mode, a heat pump reverses the flow of refrigerant. The indoor unit absorbs heat from the air inside your home, and the outdoor unit releases that heat outside.
While cooling, a heat pump can provide:
- Summer air conditioning
- Moisture removal, because water condenses as warm indoor air passes over the cold indoor coil
What Allows a Heat Pump to Switch Between Heating and Cooling?
A reversing valve changes the direction of refrigerant flow. That lets the same equipment heat your home in one mode and cool it in the other.
The thermostat tells the system which mode to use. For normal operation, ENERGY STAR recommends selecting heat or cool instead of leaving the system in automatic mode. Automatic mode can cause unwanted switching during unusual weather.
Do All Heat Pumps Heat and Cool?
Most residential heating and cooling heat pumps do, but not every product called a heat pump serves the same purpose.
- Air-source heat pumps: Usually provide heating and cooling.
- Ductless mini-split heat pumps: Usually heat and cool individual rooms or zones.
- Geothermal heat pumps: Provide heating and cooling by transferring heat to and from the ground.
- Heat pump water heaters: Heat domestic water and generally do not replace a home heating and cooling system.
Can a Heat Pump Heat a Home in Cold Weather?
Yes. Modern cold-climate heat pumps are designed to operate at low outdoor temperatures. Heating capacity and efficiency can decrease as the temperature falls, so correct sizing, good insulation and professional installation matter.
Some homes use a dual-fuel system, which combines a heat pump with a gas or oil furnace. The heat pump handles heating when it is efficient. The furnace provides backup heat during colder conditions or when fuel costs make it the more economical option.
Is a Heat Pump Better Than Separate Heating and Cooling Systems?
A heat pump can be a practical alternative because one system provides both functions. It can replace or reduce reliance on a separate furnace and air conditioner, particularly when the home has suitable ductwork or can use ductless indoor units.
A heat pump may suit your home when:
- You need to replace both an air conditioner and a heating system
- You want electric heating and cooling
- Your home has good insulation and properly sized equipment
- You prefer one system for year-round temperature control
The choice depends on your climate, electricity and fuel prices, existing ductwork, insulation and installation cost.
Bottom Line
A heating and cooling heat pump conditions the home by moving heat in opposite directions. A heat pump water heater is a separate product that heats domestic water.