What Is a Heat Pump and How Does It Work?

If someone mentions a "heat pump," you might picture some kind of heater. But here's the thing: a heat pump is actually a complete heating AND cooling system in one unit. It looks like an air conditioner, works like an air conditioner in summer, and provides heat in winter—all using the same technology.

Let's break down how this works in simple terms, without the engineering jargon.

The Simple Explanation

A heat pump doesn't create heat—it moves it. Think of it like a pump that moves water, except it's pumping heat energy from one place to another.

• In summer: Pumps heat OUT of your house (just like AC)
• In winter: Pumps heat INTO your house (the reverse)

How a Heat Pump Works (Simple Version)

Cooling Mode (Summer)

This is exactly how air conditioners work. In cooling mode, a heat pump IS an air conditioner.

Heating Mode (Winter)

Here's where it gets interesting. The heat pump reverses the process:

Why Heat Pumps Are So Efficient

Traditional heating (furnaces, electric heaters) creates heat by burning fuel or converting electricity directly to heat. This process is at most 100% efficient—you get out what you put in.

Heat pumps move existing heat rather than creating it. This is like the difference between carrying water uphill in buckets versus pumping it through a pipe. The pump method takes far less energy.

A heat pump rated at 300% efficiency (common in Charlotte's climate) delivers 3 units of heat for every 1 unit of electricity consumed. You literally get more heat out than the energy you put in—because you're harvesting heat from outdoor air.

Do Heat Pumps Work in Cold Weather?

This is the most common question we get. The answer: yes, but with limitations.

Modern heat pumps work efficiently down to about 25-30°F. Below that, they still work but efficiency decreases. In extremely cold weather (below 10-15°F), some heat pumps need backup heat.

Heat Pump vs. Air Conditioner: What's the Difference?

Physically, heat pumps and air conditioners look nearly identical. The difference is internal:

• Air conditioner: Only cools (one-way heat transfer)
• Heat pump: Cools AND heats (reversible heat transfer)

A heat pump has a reversing valve that lets it switch direction. This adds about $500-1,000 to the cost compared to an AC-only unit, but you get heating capability included.

Types of Heat Pumps

Air-Source Heat Pumps (Most Common)

Transfer heat between your home and the outdoor air. This is what most people mean by "heat pump." Cost: $7,000-$18,000 installed.

Mini-Split Heat Pumps (Ductless)

Same technology, but without ductwork. Great for room additions or homes without ducts. Cost: $3,500-$6,000 per zone.

Ground-Source Heat Pumps (Geothermal)

Transfer heat to/from the ground instead of air. Extremely efficient but expensive to install due to required underground piping. Cost: $20,000-$40,000.

Should You Get a Heat Pump?

Heat pumps make excellent sense for most Charlotte homes because:

• Our mild winters are perfect for heat pump efficiency
• You get heating AND cooling in one system
• Operating costs are typically lower than gas + electric AC
• Electric is often cheaper than gas in our area
• Environmental impact is lower than burning gas

Gas furnaces might still make sense if: gas is very cheap in your area, your home has poor insulation (needs high-output heat), or you strongly prefer the feel of gas heat.

Frequently Asked Questions