Choosing the Right Heat Pump for Your Home

Heat pumps are great for adding heating and cooling to rooms the existing ductwork doesn’t reach. They’re also easier to install than hydronic or ductless systems.

Energy Efficiency

Heat pumps are much more efficient than traditional furnaces and air conditioners because they don’t burn fossil fuel to heat or cool the air directly. However, their energy efficiency also depends on how efficiently the system is installed and used, especially when paired with a supplemental heating system such as baseboards or resistance elements in ductwork. For instance, high-performing Mitsubishi heat pumps can provide lower energy costs with ultra-quiet heating sources for your home.

Your installer needs to do a detailed size calculation based on your local climate, the heating and cooling loads of your home, and the goals of your installation (e.g., maximizing heating energy savings vs. displacing existing systems during certain periods of the year).

Size

The size of your home’s heating and cooling system is crucial to its performance and cost. Getting it right ensures your heat pump has enough oomph during the coldest and hottest days while avoiding wasted energy.

Accurate sizing isn’t something you can do yourself: The best contractors know how to perform a manual J load calculation, which looks at a home’s square footage, insulation quality, climate, windows, and more to determine the correct unit size. But even a small change in assumptions can drastically impact the results.

This is why simple rules of thumb are pretty worthless. They’re wrong way more often than right, leading to systems that need more oomph to keep up with a home’s demands or are too large and waste energy. The goal is to match a unit’s maximum capacity during extreme temperatures with its total heating and cooling “load” (measured in Btu/h).

Climate

It’s not often that a new technology that makes serious strides toward decarbonization saves you money on energy bills and has few drawbacks — but heat pumps are one such piece of equipment. They can replace fossil fuel-based heating systems like propane or oil, electric resistance heaters, and gas furnaces.

The climate you live in affects the performance of a heat pump. Cold climates require more energy to extract heat from the air because it is harder for the unit to find enough heat to meet your home’s needs.

If your home needs to be better insulated, it can cause a heat pump to overwork itself to keep up with heating and cooling demands. You can limit this problem by having an experienced contractor perform a Manual J load calculation on your home (using a blower door) to ensure the system is properly sized. This prevents overworking the system, which results in hot and cold spots around your home and reduced energy efficiency.

Installation

If you want to switch to a heat pump, seek a contractor with experience installing them. Ask for referrals from other homeowners, and check with local green-energy resource groups. Then, schedule a home consultation. During the visit, the contractor will take measurements and talk to you about your goals for the system. This includes how much you will spend on the new unit and whether you want to keep backup heating (since heat pumps don’t create as much heat). A good contractor will also help you understand your climate zone and load calculations.

Depending on the contractor, this consultation could last anywhere from 30 minutes to 2 hours. Many pros tell us it’s OK to get a few of these consultations—even weeks or months before you switch—and compare bids as you shop around. That gives you time to consider other upgrades your house might need before you can make the switch, like ductwork modifications or insulation and air sealing.