Heat pumps can serve as a whole-home heating and cooling solution in Massachusetts. That was the primary takeaway of MassCEC’s Whole-Home Heat Pump Pilot, which ran from May 2019 through June 2021. And whole-home heat pumps will be fundamental to the Commonwealth meeting our goal of one million households using high-efficiency electric heating systems by 2030.
Whole-home heat pumps are essentially heat pumps that serve 100% of a building’s heating needs. While heat pumps are increasingly common in Massachusetts, many are supplementary to fossil fuel heating systems in homes. However, as the state increasingly electrifies its buildings, more and more will rely on heat pumps for all of their heating needs.
Whole-home heat pumps offer many benefits. First, they deliver a comprehensive heating and cooling solution that serves the whole house, increasing comfort and convenience. Second, they do not require homeowners to maintain and operate two separate heating systems. This eliminates the need to maintain fossil fuel pipes or tanks and keeps the homeowner from needing to maintain and potentially replace a second heating system in their home. And last, whole-home heat pumps deliver superior emissions reductions and will continue to get cleaner as the state’s electricity transitions toward being carbon free.
MassCEC’s pilot worked to demonstrate that whole-home heat pump systems offer a high-performance solution today and that the market is ready for significant expansion going forward.
Background on the Whole Home Heat Pump Pilot Program
MassCEC launched the Whole Home Heat Pump pilot shortly after ending our larger Residential Air-Source Heat Pump Program, which had run from November 2014 through March 2019 and supported the installation of air-source heat pumps at over 20,000 homes. In January 2019, Mass Save® expanded its incentives for supplemental air-source heat pumps – at least for customers switching from oil, propane, and electric resistance. This allowed MassCEC to shift its focus to demonstrating the benefits of whole home air-source heat pumps.
In order to ensure that supplemental heat pumps are being used for heating and to access their higher incentives, Mass Save® requires oil and propane customers switching to heat pumps to either install integrated controls that operate both their heat pumps and their fossil fuel system or remove their fossil fuel system. When Mass Save® launched their incentive, they discouraged the removal of the backup system due to concerns about customer comfort at the coldest temperatures, but they recently removed this language, reflecting growing acceptance of the ability of cold-climate heat pumps to serve as a stand-alone heating solution.
A major goal of MassCEC’s pilot was to demonstrate that heat pumps can be stand-alone solutions, so hopefully our pilot has helped contribute to acceptance of this approach as another option for customers along with integrated controls depending on the customer’s situation and goals. MassCEC also hoped that the pilot would surface cost-effective and efficient design strategies for whole-home air-source heat pump solutions. Some of these cost-effective projects are highlighted in the case studies below.
Awarded Funds under the Whole Home Heat Pump Pilot Program
The MassCEC pilot offered a flat incentive of $2,500 per home for existing homes that were switching from natural gas to whole-home heat pumps or new construction/gut rehab homes that had whole-home heat pumps and had no fossil fuel appliances in the home. In order not to overlap with Mass Save incentives, the MassCEC pilot was only open to residents that heated with natural gas (and were therefore not eligible for the higher Mass Save® incentives). Based on current fuel prices, customers heating with natural gas have the lowest value proposition for switching to heat pumps, but MassCEC knew that there were residents interested in making this transition, and we wanted to support these projects while gathering project data that could be used to inform future state programs and policies. The MassCEC pilot offered higher incentives for income-qualified customers and, towards the end of the pilot, MassCEC created an adder for projects that included other efficiency or electrification measures as part of the heat pump project.
In the two years that we ran the pilot, we awarded funds to 168 whole-home heat pump projects: 31 new construction projects and 137 retrofit projects (including 11 gut rehabs). About a quarter of the projects either received an income-based adder for low and moderate income homeowners or were affordable housing projects. A total of 39 installers participated in the pilot.
The primary lesson learned is that whole-home heat pumps are a feasible solution, not only for new construction, but also for retrofitting existing buildings, including older homes. See the case studies linked below for stories of homeowners who have been heating their homes with heat pumps. We surveyed pilot customers six months after project completion, and 95% of respondents were somewhat or fully satisfied with the level of comfort for heating, while all were somewhat or fully satisfied with the level of comfort for cooling. We encourage homeowners thinking about whole-home heat pumps to start with making their home as efficient as possible. Tighter homes can install smaller and/or less heat pump equipment, will be more comfortable, and will have lower operating costs. A no-cost Mass Save® Home Energy Assessment is a great place to start if you live in Mass Save® territory. Homeowners across the state can refer to MassCEC’s Weatherization Checklist.
Costs for Whole Home Heat Pump Solutions
Costs were higher than we hoped. As shown in the table below, median project costs for the pilot were $18,400. We saw less expensive costs for new construction projects versus retrofits, probably largely because new construction homes had smaller loads so they could install smaller/less heat pump equipment. Also, the heat pump equipment could be designed with the house from the beginning instead of retrofitted. For retrofits, some of the more affordable projects that we saw were for projects that could reuse existing ductwork and/or had smaller homes without a lot of small rooms. Some of those projects are described in the case studies below. Our hope is that costs for whole-home heat pumps projects will go down, as installers become more comfortable with the capabilities of heat pumps and manufacturers offer more options. However, because heat pump technology is relatively mature worldwide I do not expect to see the rapid price declines that solar photovoltaic projects have seen (although I hope I’m wrong!), so I expect that incentives will continue to be necessary to achieve the state’s electrification goals, especially for low and moderate income homeowners.