What Is a Heat Pump? How It Heats and Cools a Prescott Home

A heat pump is an electric heating and cooling system that moves heat instead of generating it. In summer it pulls heat out of your house and releases it outdoors, exactly like an air conditioner. In winter it runs in reverse, pulling heat out of the outdoor air (even cold air holds heat) and bringing it inside. Moving heat takes far less energy than creating it, so a heat pump can deliver two to four units of heat for every unit of electricity it uses.

How does a heat pump work?

A heat pump uses the same refrigerant loop as an air conditioner: an outdoor unit with a compressor and coil, an indoor coil, and refrigerant moving between them. Refrigerant absorbs heat as it evaporates and releases heat as it's compressed and condenses. The key extra part is a reversing valve, which flips the direction the refrigerant flows. That lets the same equipment heat or cool:

• Cooling mode: the indoor coil absorbs heat from your home and the outdoor unit releases it outside.
• Heating mode: the outdoor unit absorbs heat from outside air and the indoor coil releases it into your home.

What's the difference between a heat pump and an air conditioner?

In summer, none. A heat pump cools exactly like an AC and is rated with the same SEER2 efficiency rating. The difference is that a heat pump can also run in reverse to heat your home. An AC only cools, so it's usually paired with a furnace.

Heat pump vs. furnace: which is more efficient?

A furnace makes heat by burning gas or propane, or by running electric resistance coils. Even the best gas furnaces convert at most about 98% of their fuel into heat. A heat pump moves existing heat, so it often delivers 200–400% efficiency (a coefficient of performance of 2 to 4). Two more differences:

• No combustion. A heat pump burns nothing, so it creates no carbon monoxide risk and needs no flue.
• Gentler heat. A heat pump delivers warm air over longer, steadier cycles rather than short blasts of very hot air. That's why it can feel lukewarm. See why your heat might be blowing cold air.

Whether a heat pump costs less to run than gas depends on your local utility rates and the equipment's efficiency. We'll run the comparison for your home instead of guessing.

Do heat pumps work in Prescott winters?

Yes, if you choose the right equipment. Prescott winter nights regularly drop into the 20s, with occasional dips into the teens. Older and entry-level heat pumps lose capacity as it gets colder and lean on backup electric heat strips. Today's cold-climate heat pumps keep heating well below zero. Mitsubishi rates its Hyper-Heat line to operate down to −13°F. As a Mitsubishi Diamond Contractor, that's the equipment we specify most often for this climate.

Want a gas backup anyway? A dual-fuel system pairs a heat pump with a furnace. The heat pump covers most of the season, and the furnace takes over on the coldest nights.

What types of heat pumps are there?

• Ducted (central) heat pumps replace a central AC or furnace and use your existing ductwork. That works well if your ducts are in good shape.
• Ductless mini-splits mount an indoor head in each room or zone with no ducts at all. They're ideal for additions, garages, casitas, and older homes. See ductless Mitsubishi mini-splits.
• Packaged heat pumps put everything in a single outdoor cabinet, common on manufactured homes and rooftops.

Does a heat pump need electrical upgrades?

Sometimes. A heat pump needs a properly sized dedicated circuit and an outdoor disconnect. If you're replacing a gas furnace, total electrical load goes up, and an older 100-amp panel may need a panel or service upgrade. Most HVAC companies have to subcontract that work. We're licensed for both HVAC and electrical, so the same crew sizes the system, runs the circuit, and handles the panel.

Is a heat pump right for my home?

A heat pump is often a strong choice if:

• Your AC is near the end of its life. You'd be replacing the outdoor unit anyway. See repair or replace?
• You heat with propane or electric baseboard, which usually cost the most per unit of heat.
• You want to remove gas combustion from the house.
• You're adding space that your current system can't reach.

New heat pumps also use the newer, lower-impact refrigerants. Read about the R-410A phaseout. For help choosing, see our guide to choosing the right HVAC system, or book an install consultation. We'll size it properly with a load calculation, not by rule of thumb.