Large multifamily buildings with central heating systems that burn fossil fuels are among the hardest to decarbonize, but new systems such as window-mounted heat pumps, central air-to-water heat pumps and “mono-block” mini heat pumps provide new options for decarbonizing these buildings. We find that of the decarbonization options, window heat pumps generally have the lowest life-cycle capital and energy costs.
This report discusses these and other decarbonization options for centrally heated multifamily buildings, analyzing the life-cycle cost of the different options and providing examples of installations using each of these options. Program and policy approaches to improve decarbonization economics and other near-term steps to further use of heat pumps in these buildings are discussed.
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| Suggested Citation |
Nadel, Steven, Elizabeth Traynor, and Skye Greun. 2025. Decarbonizing Space Heating in Existing Centrally Heated Multifamily Buildings. Washington, DC: ACEEE. www.aceee.org/research-report/b2506. |
