Is a heat pump right for your Maine home? Here’s everything to know.

By Lori Valigra, Bangor Daily News Staff

Heat pumps promise eco-friendly heating and cooling at reduced costs compared with furnaces that run on fossil fuels, the predominant form of heating in Maine.

They have become so popular that the state has already reached its goal of installing 100,000 new heat pumps two years before the target date of 2025. That led Gov. Janet Mills in July to set a new milestone of installing 175,000 additional heat pumps by 2027, bringing the total in the state to 320,000. Heat pumps serve a key role in achieving the governor’s goal of reducing the state’s greenhouse gas emissions by 45 percent by 2030.

State and federal incentives are pushing up heat pump sales, as is the promise of other savings. A typical heat pump runs $4,000, about two-thirds the cost of a furnace replacement, and can save about $1,000 annually to run compared with burning fossil fuels, according to companies that install them. Heat pumps also have environmental benefits, including emitting less than half the greenhouse gasses of an average existing oil burner, according to data from Efficiency Maine, which runs the rebate program for them in Maine.

Here is some advice from experts that could help you decide whether or not a heat pump is right for your home.

What is a heat pump and how does it work?

A heat pump is a heating and cooling system that works much like a refrigerator, using electricity to transfer heat. During the winter it moves heat from the cool outdoors into a warm house and does the reverse during the cooling season. Because they transfer heat rather than generate it like conventional furnaces, heat pumps are more energy efficient. 

Some heat pumps can use the existing ducts in your home. Others, so-called mini-split units, are ductless and have a wall-mounted indoor register about the size of a suitcase to move air into a room coupled with an outdoor compressor to handle the hot or cold air. The mini-split units are connected with flexible lines containing a refrigerant.

How much can you expect to pay, and how much can it save each year?

The most popular units installed in Maine are ductless mini-splits with 9,000 to 15,000 BTUs and costing $4,700 for one heat pump and $8,500 for two, Michael Stoddard, executive director of Efficiency Maine, said. That is enough to heat a room up to 500 square feet. Additional units cost more. Rebates from Efficiency Maine, federal tax credits and local programs can help reduce the cost.

Electricity to run a standard heat pump could cost about $2,800 annually, while 1,000 gallons of oil could run about $4,000 a year, Adam Barker-Hoyt, owner of MAC Heat Pumps in Bangor, said. Because electricity prices have been rising, it could take four to five years to recoup the investment in a heat pump, he said.

How do the rebates and other incentives work?

Efficiency Maine provides up to an $800 rebate for the first heat pump and $400 for the second. Your contractor will apply for the rebate, which Efficiency Maine will either send directly to you or to the contractor to pass along. On top of that, the federal government offers up to $2,000 as a tax credit when you file income taxes. Another $600 tax credit is available if you need to upgrade your electricity panel to handle the heat pump. 

Stoddard said the rebates are not paid for by state tax revenues. Efficiency Maine gets money from the Regional Greenhouse Gas Initiative, from grid operator ISO-New England and from the electric utilities conservation fund.

How long does it take to install, and is there a wait period?

It takes a day or two to install the typical single heat pump after a contractor has surveyed the home and recommended what power is needed for a unit and where it should be placed, Barker-Hoyt said. Mini-split units require about a 2.5-inch hole drilled through the wall. Electric panels typically need to handle 15 amps for a single heat pump and up to 50 amps for multi-unit heat pumps.

Barker-Hoyt, who works mostly through referrals, said he has a one-month backlog of orders. With the rise in interest in heat pumps now, before the cold season begins, other companies are telling customers they will have to wait up to six weeks. Royal River Heat Pumps in Freeport is booking customers into October, designer Steve Bergeron said.

How might a heat pump perform in your home?

Many current heat pump users have both a heat pump and a backup system, such as their original furnace, a wood stove or even a whole-house backup generator. Since heat pumps are run by electricity, they will go out during a power outage.

Insurance companies may not provide coverage for a home with only one heat source such as a heat pump, so it is best to check before you choose that option.

Stoddard said heating with only heat pumps is becoming more popular, with about 20 percent of new construction using only them as a heat source.

Does it work in very cold weather?

Heat pumps work best in the shoulder seasons, even though new technologies allow them to operate up to minus 15 and even minus 30 degrees. A new generation of heat pumps focused on operating in cold climates came onto the market starting in 2012, Stoddard said. Also helping is R410A, a high-pressure refrigerant that can work to minus 30 degrees, Barker-Hoyt said, with those systems being popular in Aroostook County. He said even at minus 10 degrees, heat pumps are twice as efficient as standard heat.

Will I have to change anything in my house to install it?

You may have to get a more robust electric panel or backup generator depending on their age and the type of heat pump system you install. You also may have to change the location of your thermostat if it is near the heat pump. That is because the heat pump will bring the room up to the temperature requested by the thermostat, but other rooms in the house connected to the thermostat but not in the range of the heat pump may get too cold in the winter, Stoddard said. Each heat pump also has its own thermostat if there are multiple units in different rooms.

Are there any limitations or downsides to installing a heat pump?

The current lifespan of a heat pump is about five years less than a fossil fuel furnace, which typically lasts 20 years, Barker-Hoyt said. Also, it is important to place the outdoor unit in a mini-split system away from the drip edges of homes and at the gable end. Having a unit that is correctly sized for the space it is heating and cooling also is important. A unit that is more powerful for the colder months, when there might be five very cold days, will run too much during the other times of the year, he said. Maintenance also is important, and not all contractors offer it because of manpower shortages and because it is not a big money-making business, Barker-Hoyt said.

How will this help the state to meet the governor’s energy goals?

The state should be able to meet its new goal for heat pump installation, Bergeron said. He expects the current steady demand to ramp up over the next couple years as word about heat pump benefits spreads among consumers.

Since 2019, some 115,442 heat pumps have been installed through Efficiency Maine and MaineHousing, according to state data. The amount of energy those heat pumps offset, compared to heating fuels, is equivalent to about 21.1 million gallons of heating fuel annually, or about $80 million in fuel costs annually at today’s per-gallon prices.

The state measures its progress toward climate goals in a report every Dec. 1. 

Valigra is an environment reporter for the Bangor Daily News. She may be reached at lvaligra@bangordailynews.com. Support for this reporting is provided by the Unity Foundation and donations by BDN readers.