Heat Pumps 101
Heat pumps are new to many of us and they can be hard to understand. But they are worth the study. Here are their benefits:
Great savings on operating costs in many situations
Cooling at no extra cost—no air conditioner needed
Reduced greenhouse gas emissions, especially when powered by renewably-sourced electricity
Access to generous subsidies through Commonwealth and federal programs
Lincoln’s Green Energy Committee is committed to helping residents make their homes as energy efficient and sustainable as possible. Heat pumps are one way to do so. In fact, since residential heat accounts for about 30 percent of Lincoln’s greenhouse gas emissions, they are essential for meeting Massachusetts’ climate goals for 2030 and 2050.
The Green Energy Committee has prepared this step-by-step guide to help you decide which heat pumps are right for your home and navigate the selection and installation process successfully.
1. Weatherize. The first step before installing a heat pump is to weatherize your house so that it does not leak heat. The tighter the house, the less expensive the heat pump required and the lower your energy bills. Learn about how to weatherize your house here.
3. Finance. Generous rebates, tax credits and no-interest loans can help you finance a heat pump and weatherize your home for a lot less than you might expect. Explore these incentives and two examples of retrofitting a home here.
4. Execute. Finding a good installer is critical to choosing the right system for your home and installing it correctly. Help with these important steps can be found here.
1. Weatherize First
Tighten up your home before adding heat pumps. A more energy-efficient house means a smaller and less expensive heat pump, fewer drafts and lower energy bills for years to come.
Air Seal your house. (See Notes on Key Weatherization Steps below.)
Windows: Double-pane at a minimum; Triple-pane when replacing single-pane (otherwise, no access to good financing.)
U.S. Energy Star guidelines for insulation in Massachusetts are:
Attics: R49-60 (13”-16” of blown-in cellulose)
Walls: R18-19 (R13 insulation in wall plus R5-R6 insulating sheathing outside)
Floors: R25-30 for floors over unconditioned spaces (8”-9” of fiberglass batts)
(2022 values. These are likely to increase.)
You may not be able to meet all of the above guidelines in your home, but the closer you get in each category, the more long-term savings you’ll realize. Homeowners can take strong steps towards reaching these goals for very little out-of-pocket expense, due to the powerful rebates currently in effect.
Process. Start with a free MassSave Home Energy Assessment (HEA) by calling HomeWorks Energy at 781-305-3319. In preparation for their visit, review MassCEC’s Weatherization Checklist to identify the most common ways to make your house more energy efficient. The checklist notes that “Weatherization solutions that fall outside of the incentives from Mass Save® or your electric provider may not be proactively suggested during a professional home energy assessment. However, all the items on this checklist are still important to investigate when tightening your home's envelope, especially if you are considering electrifying your home's heating.” In other words, you may have to pay the full cost of some items, but those may still be critical to meeting your energy-saving goals. The checklist concludes: “Use this checklist to get the most out of your meeting with a home energy assessment professional.”
Even if the measures you plan to take to meet your weatherization goals are covered by MassSave rebates, be sure that the HEA technician includes them on their report of recommended actions. Otherwise, the rebates may not be honored.
Implement the HEA recommendations to ensure you will be eligible for very substantial rebates on your heat pump purchase. Your contractor or HEA technician should supply you with a form to submit, verifying completion of the recommended work, and should describe the process for obtaining your rebate.
Notes on key weatherization steps:
Air seal first, before adding insulation. Air sealing means blocking as many air leaks as possible. Per the EPA, Air infiltration is the source of 25%-40% of your heating bill. This EnergyStar publication has a good visual showing common places where air leaks into and out of your home.
If insulation in your walls is original from the 60s or earlier, it is almost certainly insufficient. Consider adding insulation to walls when replacing siding (it can be added from the outside without removing some kinds of siding) or before doing interior painting or other renovations. As noted above, rebates reduce out-of-pocket costs greatly.
If your home has no attic and your roof insulation is installed above the roof deck, then don’t miss the opportunity to add needed insulation when replacing your roof. Otherwise, it will be 20-30 years before this chance comes again, and the climate crisis won’t wait. Above-roof foam insulation is not currently covered by any MassSave rebates (2022).
If your home still has some single-pane windows, replacing them should be a high priority, as they are a major source of heat loss in a home. MassSave will provide no-cost financing for replacements to single-pane, but only if the new windows are triple-pane.
MassCEC. Massachusetts Clean Energy Center offers a great overview of everything to consider when thinking of installing a heat pump, with detailed information just a click away. MassCEC’s website discusses Air-Source Heat Pumps (ASHPs) and Ground-Source Heat Pumps (GSHPs).
For each type of heat pump, they cover:
How they work
Are heat pumps a good fit for your home?
Types of Air-Source Heat Pumps (ASHP section only)
Benefits and Costs
Incentives and Financing
Questions to ask your installer
MassCEC does not cover Air-to-Water Heat Pumps (AWHPs) in any detail. AWHPs take heat from outside air to heat water for domestic use or to heat your home. However, HeatSmart Alliance (see below) provides a homeowner guide describing AWHPs and their pros and cons. They note that as of 2022, only a handful of installers in Massachusetts have experience installing AWHPs for home heating. That said, if you are willing to be an early adopter, there is a lot of promise in this technology. Here is a link to the list of AWHPs that meet MassSave’s criteria.
MassCEC provides a chart comparing the carbon footprint and the operating cost for different heating options. Note that the cost data is based on averages over the last five years, which do not reflect current (2022) fossil fuel costs.
NEEP. Northeast Energy Efficiency Partnerships (NEEP) also has excellent information on air-source heat pumps. They offer a great buying guide that describes the different types of air-source heat pumps, dispels common myths about heat pumps and provides a step-by-step guide to choosing an installer and purchasing a system.
In addition, you can read three case studies about New England families’ experiences with heat pumps.
HeatSmart Alliance is a non-profit working to reduce greenhouse gas emissions by accelerating adoption of energy-efficient heat pumps in Massachusetts’ homes and buildings. Here are some FAQs from them, on the Green Energy Committee website: Air-Source Heat Pump FAQs and Ground-Source Heat Pump FAQs.
Other Sources of Information. Watch video of Lincoln Green Energy Committee presentation on heat pumps.
Lincoln resident Belinda Gingrich is a heat pump coach, working with the HeatSmart Alliance to help homeowners transition to heat pumps. Belinda.Gingrich@gmail.com
Green Energy Consumer’s Alliance (GECA) offers Independent Advice About Heat Pumps to help homeowners find good installers and provide (for a fee) in-depth consultation on heat pump decisions and quote analysis.
Massachusetts rebates for heat pumps increased substantially in 2022. In conjunction with other generous MA rebates and 0% 7-year loans and applicable Federal tax credits, the costs of weatherization or installing a heat pump can be greatly reduced. See the MassSave website for full details on incentives for heat pumps and weatherization. Here’s a summary:
2022 Heat Pump Incentives
$15,000 for whole-home Ground-Source Heat Pump (GSHP)
$10,000 for whole-home Air-Source Heat Pump (ASHP) replacing natural gas, oil, or propane
All systems are eligible for $25,000 0%-interest, 7-year HEAT loan (Heat pumps must be on MassSave qualified product list in order to obtain rebates.)
Electrical panel upgrades are now included
Federal tax credits
26% on GSHP total cost in 2022 (22% in 2023 and zero in 2024)
2022 Weatherization Incentives:
75% rebates (up to 100% for income-eligible homeowners) for:
If you replace single-pane windows with triple-pane windows, you can finance up to $25,000 of the expense using Mass Save's® 0% 7-year HEAT Loan. They will also provide a $75 rebate on each window. Note: The total amount for heat pumps and/or windows cannot exceed the $25,000 limit per home.
Here are two examples of the expenses the owner of an average 2000 sq. ft. home might incur when doing significant weatherization and then adding a whole-house heat pump, showing how much more affordable such major work can be because of incentives. The costs for weatherization are from an experienced local contractor. Costs for the heat pumps are mid-range values from the MassCEC site.
Probably the most important decision you will make in the course of your project is in the choice of your installer. The heat pump industry is still relatively young and there aren’t a lot of experienced installers yet. A good installer is critical to getting a heat pump system that’s right for you and installed well. It’s more important than for standard HVAC systems where most vendors have a lot of experience.
Review the NEEP Buying Guide to better understand the alternatives available and to find a good installer. (Ground-Source Heat Pumps are not covered in part one, but nearly all of part two will be applicable to them.) Here are a few key takeaways:
Get names of installers from trusted sources who have had good experience with them. One source is the list of LincolnTalk recommendations for HVAC contractors.
Get at least three bids. You’ll learn from each vendor and each will often offer you a different approach.
Ask the installers the questions listed in part two of the buying guide.
Make sure your installer will do “Manual J” calculations of how much heat the heat pump(s) will need to produce. Don’t let the installer use rules of thumb.
Make sure the heat pump your installer recommends is on the MassSave list of qualified products, so that your rebate request will be honored. In addition, the model chosen should meet the NEEP specification for cold-climate heat pumps (See NEEP above), especially with regard to its performance at 5° Fahrenheit.
If you are planning to use existing ductwork, be sure your installer verifies that it is sized adequately for heating and cooling and that it is well-constructed. Ducts installed before the mid-90s are likely to be very leaky and will thus yield higher heating and cooling bills.
When installing ductless ASHPs, work with the installer to choose the best routes for the refrigerant lines (both outdoors and indoors) and condensation drain lines from the indoor units. Otherwise, they can make some bad choices to save money. See p. 3 of MassCEC’s Air-Source Heat Pumps website for an example of how outdoor refrigerant lines are normally run. The refrigerant lines can, of course, be run inside the walls of the house, but the cost will be higher and problems may be harder to find.
Consider whether lowest first cost is more important to you, or long-term efficiency and low operating costs. Some installers may push lower-cost (and less efficient) units to make a sale, leaving the customer with higher heating bills. Compare the efficiencies of units proposed by different vendors.