How a heat pump can decarbonize your home

If your home is heated by natural gas or oil (like most in Quincy), there’s no getting around it: You’re burning a lot of carbon each winter. And probably a lot of money, too: The price of gas and oil heat is expected to jump 30% or more this winter. But a heat pump can efficiently heat your home — even on the coldest New England winter day — without burning fossil fuels. 

What is a heat pump? It’s essentially an air conditioner that can also run in reverse. In summer, like an air conditioner or refrigerator, it removes heat from your home. And in winter, as long as there is some heat energy in the air — and there’s always some, until we reach absolute zero, a.k.a. negative 273º Celsius — the outdoor condenser pulls whatever heat it can find out of the atmosphere and uses a special refrigerant to send that warmth inside to the blower unit.  

That’s the reason heat pumps are so incredibly efficient: Instead of generating heat, they’re simply moving it around. The highest-efficiency gas boilers can deliver up to 0.95 BTUs worth of heat per BTU of gas consumed, making them 95% efficient — pretty good! But an air source heat pump delivers up to three times more BTUs of heat energy than it uses to operate. And newer cold-climate heat pumps can now operate efficiently even at -17 degrees Fahrenheit

Electric heat got a well-deserved bad rap decades ago, but modern heat pumps cost about 50% less to run than traditional electric resistance heaters. And though the upfront cost of installation can be high, there are rebates, zero-interest heat loans, and other incentives available through MassSave to help homeowners afford heat pumps. (Equipment rebates are currently higher for homes heated with oil, but that’s expected to get an update in 2022.) 

Air-Source vs. Geothermal, Ducted vs. Mini-Splits
A mini-split doesn’t require any ductwork: It includes a main outdoor condenser unit that connects to one or more indoor blower units, which can be mounted on the wall, on the floor (like a radiator), or even set in the ceiling. Mini-splits are useful for homes without ductwork, like those with hot-water or steam boilers (radiator or baseboard heating). 

How to make the switch
Before switching to an electric heat pump, it’s worth fully insulating and air sealing your home. MassSave offers substantial reimbursements for this, and it will save you energy and money no matter how you heat your home. 

If you’ve already insulated, here’s when it makes the most sense to install a heat pump:

1. If your heating system is aging or needs replacement. Boilers and furnaces have an expected lifespan of about 15 to 20 years. If yours is getting on in years, consider transitioning to a full electric heat pump or mini-split system, or at least installing one in the main living area to take some of the burden off your old boiler or furnace. Leave the old heating system in place for a winter to see whether you need to run it on the coldest days. With any luck, you won’t, and you could even reclaim some valuable floor space when it finally conks out by removing the old system and radiators.

2. If your home produces solar power. Installing heat pumps can get expensive, and while they use much less electricity than traditional electric heaters, they still require some power. But if you’re creating free renewable electricity on your roof, and you switch from oil or gas to ultra-efficient electric heat… well, you could end up getting a lot of that heat for free.  

3. If you’re considering central air. Aside from the initial cost — some of which can be offset through MassSave incentives — there is really no reason to put in just central air at this point, when you could be getting central air and heat. 

The Secret to Carbon-Free Heat
Because heat pumps run on electricity, they have the potential to be a carbon-free source of heating and cooling for your home — though not by default (Massachusetts’ Clean Energy Standard currently requires only 22% of electricity to be procured from clean energy sources). Whether you have a heat pump or not, take one of these steps to ensure you’re using renewable electricity in your home: 

1. Opt in for green power. The simplest way to ensure you’re using clean electricity is to opt in to 100% New England-generated renewable power through National Grid. (If approved, the Quincy Community Electricity program currently under review with the Department of Public Utilities will enable Quincy residents to “opt-up” to a higher mix of renewables, up to 100%.)

2. Install rooftop solar panels. Produce your own renewable, clean electricity by installing rooftop solar panels on your home. You can compare quotes on; buying your panels is generally a better long-term investment than leasing them (though leasing requires no upfront expense), and low-interest solar loans are available to help.

3. Subscribe to community solar. If you’re a renter, or your home simply can’t support solar panels, you may still be able to purchase 100% solar energy by subscribing to a community solar farm in Massachusetts, and you’ll save about 10% on your electricity bill while you’re at it. 

Learn more about heat pumps and the incentives available to Quincy residents at – and come to QCAN’s Heat Pumps 101 event on January 19 at the Thomas Crane Library at 7 p.m.

– Jon Gorey, QCAN Member

IMAGE: Exterior heat pumps recently installed in a two-family Quincy home. (photo: Jon Gorey)