Should You Replace Your Furnace and AC with a Heat Pump?

heat pumps outside a building

These days, greener is better, and so is saving money on your energy bills. Furnaces and AC units are typically the biggest guzzlers, and account for 43% of monthly expenses.

Heating and cooling costs will depend on your region, but Americans spend $875 annually on average. One way to circumvent these high costs is to invest in a heat pump. They don’t use fossil fuels, and can reduce heating and cooling costs by as much as 75 percent.

There are a lot of variables to consider, so this article will go over some of the heat pumps available, and whether you should replace your current HVAC system with one of them.

What Is a Heat Pump?

An air-to-air heat pump is an energy-efficient, ductless way to heat and cool your home. These heat pumps consist of an indoor and outdoor unit that are connected through simple refrigerant and drain hose pipes.

Installation is fairly easy, and only requires a wall for the indoor unit to attach to, as well as space outside for the outdoor unit, ideally just on the other side of an exterior wall.

Heat pumps draw in cold air from the outside, turn it into warm air with a refrigerant, and transfer it inside during colder seasons. When it’s warm outside, this process is reversed, and the heat pump draws hot air from inside the house to provide cool air.

How Does it Work?

The indoor wall unit is controlled by a thermostat, just like a furnace, so you can adjust the settings and temperature easily. The outdoor unit has a fan and looks similar to central air conditioning outdoor units. The difference is, a heat pump provides heat as well as cool air, depending on the home’s needs.

Air-to-air heat pumps are actually quite simple, and work from a basic system that includes a compressor, condenser, refrigerant, and fans—again, very similar to central air conditioning systems.

A refrigerant line carries the hot air to the indoor unit, which also has a fan that pumps out the heat. To cool the home, the two units reverse the process, and the indoor unit draws in warm air through the fan, sends it through the refrigerant line, where the outdoor unit pushes that warm air out, and returns cool air in.

Can It Heat the Whole House?

Essentially, air-to-air heat pumps may be able to heat your whole home. However, there are many variables at play. Hot and cold air are only transferred from the spot where the indoor unit is installed, so a single heat pump will work best on open floor plans, smaller homes, in areas that don’t experience harsh winters, or as an energy-efficient space heater.

For larger homes and colder climates, there are multi-zone heat pumps in addition to single-zone models meant for whole-home heating and cooling. The multi-zone heat pumps have one outdoor unit with 2-4 indoor units (or heads) to cover every area of your home.

Performance of heat pumps has improved dramatically in recent years, allowing even single unit models to draw heat from sub-zero outdoor conditions. Heat pumps can also be installed to work alongside a furnace system so that extra heat is provided during the coldest months in what is called a dual fuel system.

Heat Pump vs Air Conditioner

air conditioner condenser

You may wonder if an air-to-air heat pump can cool the home as efficiently as a central air conditioning unit. The thing is, they are essentially the same thing. When the heat pump is in cool mode, it works in the very same way as your typical AC unit by pulling in warm air from the home, and then cooling it with a refrigerant. Fans then push that cooled air back into the home.

In terms of efficiency, heat pumps out-do air conditioners every time, although check the SEER rating of any appliance to see how energy-efficient it is and look for ENERGY STAR labels, as well. In general, a heat pump will use five times less energy than an air conditioner.

They will also outperform air conditioners when temperatures start to get really hot. An AC unit only has a certain capacity until it can’t cool your home faster than the outside is heating up. A heat pump won’t have that problem, as they maintain their ability to cool at all times.

Other Types of Heat Pumps

Air-to-air and air-source heat pumps are currently the most common heat pumps installed in homes. However, there are also air-to-water, and ground-sourced heat pumps that can replace furnaces as the main heating source.

Air-to-air heat pumps are more popular because they are the easiest to install, and cheapest, and you don’t have to make any modifications to your existing HVAC system.

Air-source heat pumps can fully integrate into your existing HVAC venting system, bypassing the use of the furnace, or working in conjunction with it. They are slightly less efficient than water and ground-sourced heat pumps in the long run, however.

Air-to-water heat pumps are very similar to air-to-air in terms of how heat is produced, but there is a lot more involved in the overall process and installation. Water-sourced heat pumps have an outdoor unit that connects to a home’s water heater or boiler, which then ties into an existing or newly installed “hydronic” or water-based heating system.

The heated water is distributed through radiant heat sources like radiators, radiant flooring, and/ or fan coils which makes this type of heating extremely efficient at heating the whole home. Air-to-water heat pumps make a lot more sense for very cold climates, as they will not need a supplemental heating system.

The downside is their cost and installation. Tying them into the existing water heating system is expensive up front, especially since most older radiators would need to be replaced with newer, larger ones. Most air-to-water heat pumps have a built-in function to cool the home, but not all models.

Ground-source heat pumps work similarly, but instead of drawing from an air source, they use ground temperature. They require a fair amount of excavation and need a lot of outdoor space to install the pipes. Ground heat pumps are excellent choices for homes with a lot of land, and for people that want to live off-grid.

Also called geothermal heat pumps, ground-sourced heat pumps are also more complicated and costly to install. While the initial investment is high, they are less expensive to run since ground temperatures stay more consistent than air temperatures, which is particularly enticing for colder climates.

Still, air-to-air heat pumps are the most commonly used for residential homes or commercial spaces, while providing very similar benefits to the air-to-water and ground-source units. In extremely cold climates, air-to-air will most likely need some kind of supplemental heating source, though, which is something for homeowners to consider.

outdoor heat pump fan


An average air-to-air heat pump will cost between 1000-$6000 depending on the size, type, and how many "heads" are needed, with installation around $2000. Air-sourced heat pumps that tie into existing vent systems will be a lot cheaper to install than homes that don't already have venting. This is another reason why ductless air-sourced units are so popular.

Geothermal or ground-sourced units run slightly higher at $3000-$6000. However, installation is much more costly at around $10,000-$30,000. Air-to-water heat pumps range in cost, but units are somewhere around $$4000-12,000, with installation costs highly dependent on the existing system, but similarly priced to installing a geothermal heat pump.

The overall cost-effectiveness of heat pumps depends on factors like climate, existing HVAC systems, and square footage, but a basic switch from a gas furnace or boiler can save you between $750-$2000 a year on heating and cooling costs.

Of course, the purchase and installation cost can offset the affordability, but if you are able to look at the big picture over a 20-year span, the majority of heat pumps will pay for themselves in about five years.

Increase Home Value

Another advantage to add to the cost-effectiveness of installing any kind of heat pump system is the increased resale value of your home. With climate change on people’s minds, new homeowners are very interested in ways to heat and cool their house with green energy, especially if it includes big savings on energy bills.

A heat pump system is considered to be a modern, eco-friendly, and efficient system, especially compared to outdated furnaces and AC units in older houses.

If your home’s current HVAC system needs replacing anyway, then it may make sense to invest in heat pump technology.

Specific Model Recommendations

Carrier outdoor heat pump

When shopping around for heat pumps, you’ll want to look at specifications like capacity, BTU, and both heating and cooling square footage. For example, a 1.5 ton capacity heat pump uses 18,000 BTUs, can heat 600 square feet, and cool 900 square feet. They get bigger and more capable from there.

For homeowners that live in areas with harsh winters, cold climate air-source heat pumps will be the best choice. These heat pumps will have the Energy Star acronym, ccASHP.

Carrier, Bryant, Lennox, Payne, and American Standard are just a few top brands known for selling reliable and energy-efficient heat pumps. That said, top brands don’t always have what you are looking for specifically.

With a range of options, not only in heat pump types, but also in terms of capacity, we recommend you talk with a variety of accredited installers to see what their recommendations are.

The most reliable heat pump will be the one that is best fitted to your home’s needs, and is maintained properly.

Heat Pump Maintenance

Air-source, geothermal, and air-to-water heat pumps are all meant to last up to 20 years with only minor maintenance. Repairs can be costly depending on the part, but same goes with a furnace and central air system.

Similar to typical HVAC units, filters need to be changed regularly for any heat pump to work properly. Some may need to be changed as much as once a month. Regular services from a licensed technician should be done yearly.

Outside units should be installed slightly raised from the ground so that they drain properly, and won't be affected by flooding. They should also have leaves and other debris cleared away seasonally.

Heat Pump Disadvantages

The main disadvantage to any heat pump installation is the initial cost. If your budget allows, however, then the initial investment cost isn't necessarily a disadvantage, since there will be savings in the long run.

While the ductless air-to-air heat pumps are similar in price compared to a new furnace and central AC combo, most of them aren’t capable of heating larger homes in very cold climates. Either they would have to be integrated into an existing system, or used in conjunction with another heat source.

Heat pumps are also known to be somewhat noisy since they constantly run. Unlike a furnace which turns on and off as needed, the heat pump is more efficient, and therefore uses a steadier method of heating and cooling.

You may need a permit to install a heat pump, though some smaller systems like ductless air-to-air heat pumps may be DIY-friendly. Always check with a licensed HVAC technician and follow local building codes, especially before making a large purchase.

There aren’t many other specific problems associated with heat pumps. Similar to furnaces, repairs and service calls may be needed from time to time, but they are meant to run smoothly without any serious issues.

Heat pumps are a great investment for homeowners looking for green alternatives to current heating and cooling approaches. While every household would benefit from the energy savings of a heat pump, not every household can afford the upfront cost.

Check local municipalities for any rebates there may be, either for installing a new heat pump system or for getting rid of an outdated, inefficient furnace and AC. Whether you should replace your furnace and AC with a heat pump depends on your current HVAC system, the climate you live in, and as always, your budget.

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