Heat Pump vs Furnace: What’s the Difference?

Heat pump vs. furnace is an excellent debate to consider when perusing HVAC systems for your home. Both systems provide heat, but they each manage it very differently. There are a few similarities between the ways heat pumps and furnaces operate. Both systems typically use ductwork and fans to deliver heat, but heat pumps are more comparable to air conditioners than furnaces.

Heat pumps are suitable heaters for some homes, and furnaces are better for others. There are differences in the associated costs, fuel sources, efficiencies, life expectancies, and maintenance requirements. The home’s location is also relevant when deciding between a furnace vs. heat pump. By considering the important factors, you can be sure you’ll choose the right system for your particular home.

A heat pump is an energy-efficient, environmentally friendly heating and cooling system that transfers heat. In summer, heat pumps operate similarly to air conditioners and move indoor heat outside. Unlike air conditioners, heat pumps can run in reverse and bring outdoor heat inside in winter.

To understand how a heat pump works, a basic understanding of the idea that heat tends to move away from hotter objects and spaces and rush to colder objects and spaces is helpful. An air-source heat pump has two primary units, one inside and one outside, that are connected by refrigerant lines. Cold refrigerant circulates through the system to the heat pump’s coils and absorbs heat from the surrounding air. In cooling mode, the indoor coil absorbs heat from the home’s air. In heating mode, the outdoor coil absorbs heat from the outside air. A compressor and fan assist in releasing the refrigerants’ absorbed heat at the system’s opposite end.

Furnaces are the most common space heating equipment in the country, but what is a furnace? A furnace is a heating unit that generates warmth from fuel combustion or electricity. The heat transfers to the air inside the furnace, and a fan blows the warm air through ductwork.

Gas, propane, and oil furnaces burn fuel for heat. A heat exchanger in the furnace directs toxic combustion gasses to a chimney and safely transfers the burning fuel’s heat to the air. Electric furnaces convert electricity to heat with electric resistance coils. The coils heat the air like a toaster’s elements heat bread. Electric furnaces don’t require heat exchangers or chimneys because there is no fuel combustion or exhaust.  

Heat pumps and furnaces differ in performance, maintenance, expected lifespan, and comfort. Where you live also determines which system is better for your home.

The weather largely determines heat pump performance. Heat pumps struggle to transfer heat, and efficiency reduces when outdoor temperatures are near or below freezing. On the other hand, heat pumps perform well and use less energy than furnaces in favorable conditions above 40°F. Heat pumps can be up to 300% efficient and reduce energy costs when they replace traditional space heating methods.

Furnaces are unaffected by outdoor temperatures, perform well in extremely cold weather, and deliver hotter heat than heat pumps.

Heat pumps require more maintenance than furnaces because heat pumps are used year-round. Heat pump maintenance includes monthly filter changes, snow and ice removal in winter, vegetation removal in summer, regular coil cleanings, and biannual professional inspections.

Furnace maintenance includes monthly filter changes, occasional flame sensor cleaning, and yearly professional inspections.

How long HVAC systems last is determined by usage, installation procedures, maintenance conduct, and other factors.

Heat pumps sustain more wear and tear in heating and cooling homes and last about fifteen years.

Furnaces typically last longer than heat pumps, about twenty to thirty years, because they are only used for heating during part of the year.

Heat pumps deliver mild heat and retain the air’s natural humidity. Moderate heat might be preferable in temperate regions where a furnace’s heat would be too warm and heat a home too quickly.

Furnaces produce hotter heat than heat pumps, which might be desirable in cold climates. Unfortunately, furnace heat dries out a home’s air and its occupants’ skin.

Climate zone is one of the most significant factors a homeowner should consider when choosing between a heat pump and a furnace.

Heat pumps are preferable for zones 1 to 4 because they transfer heat to homes from the outside air and become less efficient below 40°F.

Furnaces are favored in zones 5 to 7 because they are unaffected by low outdoor temperatures.

HVAC equipment prices are influenced by capacity, type, brand, and efficiency. In addition to the equipment prices, there are installation, repair, and operating expenses. The prices of labor, permits, and materials can increase the overall cost, while tax credits and rebates can lower it.

Heat pumps use very little electricity to transfer heat. Replacing an electric furnace or baseboard heaters with a heat pump can reduce electricity bills by half. However, heat pump efficiency is dependent on the climate. Furnaces use substantial energy to generate heat but heat more efficiently in cold regions.

• AFUE (annual fuel utilization efficiency) measures furnace efficiency. The rating represents how much fuel the furnace consumes is converted into heat. For example, 80% AFUE means that 80% of the furnace's fuel is converted into heat, and 20% is lost to furnace inefficiencies such as exhaust gasses. High-efficiency furnaces have ratings over 90%.

• SEER (seasonal energy efficiency ratio) measures heat pump cooling efficiency. The rating represents the amount of cooling provided over a typical cooling season compared to the total electrical input. SEER ratings range from 13 to 25 SEER. High-efficiency heat pumps have ratings above 19 SEER.

• HSPF (heating seasonal performance factor) measures heat pump heating efficiency. The rating represents the heat provided over a typical heating season compared to the total electrical input. HSPF ratings range from 6.8 to 13. High-efficiency heat pumps have ratings above 10 HSPF.

The 2023 HVAC efficiency standards the Department of Energy set forth increase the regional minimum efficiency ratings and introduce new metrics, SEER2 and HSPF 2, to measure heat pump efficiency.

Heat pumps in cold climates are not generally recommended because performance declines below 40°F. A hybrid heat pump and furnace system is a good alternative. Often referred to as a dual-fuel heat pump, a hybrid system includes a heat pump and a gas furnace.

The heat pump is used for cooling in summer and heating when temperatures are mildly cold. When the temperature drops lower than the heat pump can manage, the furnace takes over to heat the house. With a dual-fuel heat pump, you can reap the benefits of heat pump efficiency and furnace dependability.

Which system is better for your home depends on your climate, current HVAC set-up, and budget. The chief advantages of heat pumps are efficiency and versatility. Heat pumps provide heating and cooling using very little energy. Dependability is the main benefit of furnaces. Furnaces consistently deliver powerful heat despite outdoor conditions.

Heat pumps are great options for homes in moderate climates, but there are things to consider. It will be more costly if your home isn’t set up for heat pump installation. A split-system air-source heat pump replaces an air conditioning unit, requires an indoor air handler, and uses ductwork, so it wouldn’t be cost-effective to install a heat pump if your air conditioner is relatively new or your home is ductless. Mini-split heat pumps can be good alternatives for homes without ductwork and air handlers. Geothermal heat pumps are highly efficient, but the upfront cost and installation requirements are considerable.

Furnaces are better heating systems for homes in cold climates. Again, furnace installation is more costly if your home is not currently set up for a furnace. Furnaces require ductwork and access to an energy source. Natural gas, propane, and electric options make furnace installation possible in nearly any home. Dual-fuel heat pumps enable people in cold climates to reap the benefits of heat pumps and furnaces, but they are more costly.