Survey Method and Respondents
To get a window into current local heat pump installation practices, I sent a survey invitation to 2400 people on my office mailing list who had either recently subscribed or had clicked emailed links to a recent home energy survey. The survey invitation went out around 10AM on Tuesday, January 31 and the survey form was closed at 8AM on Thursday, February 2.
The survey invitation read as follows:
Sending a quick survey for people who have installed heat pumps or are thinking about them. It seeks a few specifics not covered in previous surveys.
251 people replied to the survey including some who had not installed and were not planning to install heat pumps.
Table 1: Heat Pump Status (N=251)
|Heat pump status in my home||Count|
|Don’t work for me||30|
The analysis below derives from the 210 respondents who had installed or were planning to install heat pumps (the first three categories in the table above). This overall response rate was roughly consistent with the results of our previous survey of the same group in which approximately 160 people indicated that their primary source of heat was heat pumps.
Based on zip code, approximately 175 of the 210 installed/planning-to-install respondents were in my senate district with most of the balance coming from elsewhere in Massachusetts.
Most respondents were in 1 to 4 family structures.
Table 2: Dwelling Type (N=210)
|5 or more units||18|
Responding homes had varying bedroom count, but 163 (78% of the sample) had 3 or more bedrooms.
Table 3: Bedroom Count by Dwelling Type (N=210)
|Type||1 Bdrm||2 Bdrm||3 Bdrm||4+Bdrm||Total|
|5 or more||5||8||3||2||18|
Heat Pump Installation Types
The majority of the sample made or were planning to do partial conversions — continuing to use to some extent their legacy fossil system. This was true regardless of the installation year. In the “Planned” category, many were understandably unsure as to whether their conversion would be full or partial.
Table 4: Implemented and planned systems (N=205) where system type known (N=166) by system type
|System Type||Pre-2022||2022||Planned||All Years|
Massachusetts current climate plan uses a 2020 benchmark and a 2030 goal for heat pump installation that is more skewed towards partial conversion. I believe my survey respondents skew towards being concerned about climate and they may be more likely to invest in a full conversion.
Comparison Table 1: Installed Heat Pump Metrics from 2025/30 Climate Plan Appendices
|Full||Partial||Total||Partial as % of Total|
|State Climate Plan 2020 Actual||40,000||220,000||260,000||85%|
|State Climate Plan 2030 Target||140,000||610,000||750,000||81%|
|2020->2030 Change Goal||100,000||410,000||510,000||80%|
Also worth bearing in mind is the definition of a “full” conversion. In the survey, it meant that the heating system was “heat pumps only,” but in follow up correspondence with 18 respondents who supplied their email, 5 were making continued non-emergency use of their fossil fuel system. It’s not clear what the state will be considering as “full”; the phrase used in the cited climate plan Appendix is “Homes with whole-home air source heat pump space heating,” which does not necessarily imply never using fossil.
Quantifying Use of Legacy Systems in Partial Conversions
In this sample, among those who said they were doing a partial conversion, the majority will be using their legacy fossil system through much of the heating season — the first three rows of Table 5 totaling 69%.
Table 5: Use of legacy heating systems in installed partial conversions (N=77)
|The other (non-heat-pump) system is/will be used . . .||Count||% of|
|Most of the heating season||25||32%|
|Colder days [much of the heating season]||21||27%|
|Not sure, thermostat controls [reported settings were 55 to 70]||8||10%|
|A few of the coldest days [rare use]||13||17%|
Table 6: Use of heat pumps in installed partial conversions (N=77)
|The heat pump(s) is/will be used . . .||Count||% of |
|Primarily for AC||23||30%|
|When outdoor temp above setting [reported settings ranged from 20 to 40]||11||14%|
Tables 5 and 6 together suggest that the legacy fossil systems will continue to supply a good share of the heat in many of the partial conversions. The heating load (heating degree hours) across the heating season in New England splits between hours below a temperature of about 33F and hours above that level. More detail here.
Previous heating system
While natural gas is cheap and conversions from natural gas to heat pumps usually increase operating costs, most of the heat pump conversions were from natural gas, suggesting that people in this sample lacked or were not sensitive to operating cost projections. The share of the sample converting natural gas (68%) mirrored the share of natural gas users in the much larger previous survey (65%).
Table 7: Previous heating system in installed and planned conversions (N=210)
|Before heat pumps, primary heat was||Count||% of |
Ducted systems — before and after heat pumps
Over half of heat pump conversions were from some form of ductless heat (radiators, etc.) to ductless heat pump systems. Counterintuitively, the share of conversions originating from ducted systems (34 out of 163 or 21%) was less than the share of homes having some form ducts in the larger original sample (46%). In other words, in this sample, people with non-ducted homes were apparently more likely to convert. One explanation for this could be that many were motivated in part add air conditioning through their heat pump conversion; those with ducts already were more likely to have air conditioning and be less motivated to convert.
Table 8: Ductless vs. Ducted, Before and After Conversion (where both known, N=163)
|New System||Old heating system ducted hot air||Old system not ducted hot air (radiators, etc.)||Total old systems|
|Ducted heat pumps||24||25||49|
|Ductless heat pumps||9||91||100|
|Both ducted and ductless heat pumps||1||13||14|
|Total new systems||34||129||163|
Mass Save Engagement
Most people doing heat pump conversions were engaged with Mass Save, although 11% found themselves ineligible for rebates:
Table 9: Mass Save Rebate Status (installed or planned 2018 to 2023, N=121)
|Mass Save Rebates||Count||% of Total|
|Planning to apply||27||22%|
|Total in date range||121||100%|
Satisfaction with Heat Pumps
Overall a majority were happy with their heat pumps, whether they had a full or partial conversion.
Table 7: Installed conversions (N=127) — “My feeling about my heat pumps”
Underlying data (with no identifiers) appears here — 251 survey responses.