Use Heat Pumps

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Buildings & Electricity
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Shift Energy Sources Enhance Efficiency
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Summary

Heat pumps use electricity to efficiently move heat from one place to another. This solution focuses on the replacement of fossil fuel-based heating systems with electric heat pumps. Heat pumps are remarkably efficient because they collect heat from the outside air, ground, or water using a refrigerant and use a pump to move the heat into buildings to keep them warm in the colder months. Heat pumps typically replace heating systems such as boilers, furnaces, and electric resistance heaters and many will also replace air conditioners, because the same pump can move heat out of a building in the warmer months. 

Heat stress
Income & work,Health
Air quality
Description for Social and Search
Heat pumps are a highly recommended climate solution. They replace heating systems that burn fossil fuels to reduce emissions; many can also provide cooling in hotter months.
Overview

Heat pumps use a refrigerant cycle to move heat. When the liquid refrigerant enters a low pressure environment, it will absorb heat from the surrounding air, water, or ground as it evaporates. When the refrigerant vapor is compressed, it will condense back into a liquid, releasing the stored heat into the building. By passing the refrigerant through this cycle, heat can be moved from outside to inside a building. Absorbing heat from the outside gets more difficult as temperatures drop but modern cold climate heat pumps are designed to work effectively at temperatures approaching –30°C (–22°F) (Gibb et al., 2023). The freezer in your home uses the same technology, moving heat out of the cold box into the warm room to keep your food frozen. In most systems, the refrigerant cycle in a heat pump can be reversed in the warmer months, moving heat out of a building to ensure its occupants are comfortable year-round. 

Heat pumps are very efficient at using electricity for heating. This is because they move heat rather than generating heat (e.g., by combustion). For example, a heat pump may have a seasonal coefficient of performance (SCOP) of three, meaning it can move an average of three units of heat energy for every unit of electrical energy that it consumes. Conventional combustion and electric resistance heaters cannot produce more than one unit of heat energy for every unit of fuel energy or electrical energy provided. 

Heat pump systems may be all-electric or hybrid, where a secondary fossil fuel-based heating system takes over in colder weather. 

A heat pump’s potential to reduce GHG emissions depends on the heating source it replaces and the emissions intensity of the electricity used to run it. When heat pumps replace fossil fuel-based heating, they displace the GHG emissions – primarily CO₂ – generated when the fuel is burned. When replacing electric resistance heaters, heat pumps reduce the GHG emissions from the electricity to power the system because heat pumps are much more energy efficient. As electrical grids decarbonize, the GHG emissions from operating heat pumps will decrease. 

All-electric heat pumps provide the most climate benefit because they can be powered with clean energy, but hybrid heat pumps also play an important emissions-reduction role. Hybrids consist of a smaller electric heat pump system that switches to fuel-based heating systems in colder weather. They may be attractive due to lower upfront costs and because they have lower peak power demand on cold days, but hybrids also have a smaller emissions impact. The cost and emissions analysis assumed all-electric air-source heat pumps while the data used in the adoption analysis included all types of heat pumps with the expectation that all-electric versions will dominate in the longer term. 

In this analysis, we calculated effectiveness and cost outcomes from specific countries with high heat pump adoption (European countries, Canada, the United States, Japan, and China) to avoid comparing research studies that use different assumptions. The analysis used global assumptions for heating system efficiency: 90% for fueled systems (International Gas Union, 2020), 100% for electric resistance (U.S. Department of Energy [U.S. DOE], n.d.), and SCOP of three for heat pumps (Crownhart, 2023). We also assumed all existing fueled systems use natural gas, which is currently the dominant fossil fuel used for space heating globally (International Energy Agency [IEA], 2023b). The analysis does not include emissions or costs from cooling but does assume the heat pump is replacing both a heating and cooling system. 

The cost and effectiveness analysis focused on residential heating systems for which more data are available and also because large variations in the cost and size of commercial systems make it more challenging to estimate their global impacts. Commercial heating systems are typically larger and their emissions impacts are expected to be proportionally greater per unit. Cost savings may be different due the greater complexity of heating and cooling systems (Tejani & Toshniwal, 2023). Available data on heat pump adoption, on the other hand, typically include both residential and commercial units. Our adoption analysis therefore included both residential and commercial buildings, with greater adoption assumed in the residential sector. 

Air-Conditioning, Heating, and Refrigeration Institute. (2025). AHRI releases November 2024 US heating and cooling equipment shipment data. Link to source: https://www.ahrinet.org/sites/default/files/Stat%20Release%20Nov%2024/November%202024%20Statistical%20Release.pdf 

Asahi, T. (2023, July 3). The role of heat pumps toward decarbonization [Power Point Presentation]. Japan Refrigeration and Air Conditioning Industry Association. Link to source: https://www.jraia.or.jp/english/relations/file/2023_July_OEWG45_JRAIA_side_event_Presentation_4.pdf 

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Crownhart, C. (2023, February 14). Everything you need to know about the wild world of heat pumps. MIT Technology Review. Link to source: https://www.technologyreview.com/2023/02/14/1068582/everything-you-need-to-know-about-heat-pumps/ 

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European Heat Pump Association. (2024). Heat pump sales fall by 5% while EU delays action. European Heat Pump Association. Link to source: https://www.ehpa.org/news-and-resources/news/heat-pump-sales-fall-by-5-while-eu-delays-action/ 

Gaur, A. S., Fitiwi, D. Z., & Curtis, J. (2021). Heat pumps and our low-carbon future: A comprehensive review. Energy Research & Social Science, 71, 101764. Link to source: https://doi.org/10.1016/j.erss.2020.101764 

Gibb, D., Rosenow, J., Lowes, R., & Hewitt, N. J. (2023). Coming in from the cold: Heat pump efficiency at low temperatures. Joule, 7(9), 1939–1942. Link to source: https://doi.org/10.1016/j.joule.2023.08.005 

GlobalPetrolPrices. (2023). Energy prices around the world. GlobalPetrolPrices.Com. Link to source: https://www.globalpetrolprices.com/ 

Intergovernmental Panel On Climate Change (IPCC) (Ed.). (2023). Climate change 2022 - Mitigation of climate change: Working group III contribution to the sixth assessment report of the Intergovernmental Panel on Climate Change (1st ed.). Cambridge University Press. Link to source: https://doi.org/10.1017/9781009157926 

International Energy Agency. (2020). Sustainable recovery—World energy outlook special report. International Energy Agency. Link to source: https://iea.blob.core.windows.net/assets/c3de5e13-26e8-4e52-8a67-b97aba17f0a2/Sustainable_Recovery.pdf 

International Energy Agency. (2022). The future of heat pumps. Link to source: https://iea.blob.core.windows.net/assets/4713780d-c0ae-4686-8c9b-29e782452695/TheFutureofHeatPumps.pdf 

International Energy Agency. (2023a). Net zero roadmap: A global pathway to keep the 1.5 °C goal in reach—2023 update. International Energy Agency. Link to source: https://iea.blob.core.windows.net/assets/8ad619b9-17aa-473d-8a2f-4b90846f5c19/NetZeroRoadmap_AGlobalPathwaytoKeepthe1.5CGoalinReach-2023Update.pdf 

International Energy Agency. (2023b, June 15). Builings-related energy demand for heating and share by fuel in the Net Zero Scenario 2022-2030. Link to source: https://www.iea.org/data-and-statistics/charts/buildings-related-energy-demand-for-heating-and-share-by-fuel-in-the-net-zero-scenario-2022-2030 

International Energy Agency. (2024). Clean energy market monitor. Link to source: https://iea.blob.core.windows.net/assets/d718c314-c916-47c9-a368-9f8bb38fd9d0/CleanEnergyMarketMonitorMarch2024.pdf 

International Energy Agency. (2025). Electricity 2025. Link to source: https://iea.blob.core.windows.net/assets/0f028d5f-26b1-47ca-ad2a-5ca3103d070a/Electricity2025.pdf 

International Gas Union. (2020). Global gas insights 2019 gas & efficiency. Link to source: https://www.igu.org/advocacy/graphics-data/ggi-energy-efficiency 

International Renewable Energy Agency. (2022). Renewable solutions in end-uses: Heat pump costs and markets. International Renewable Energy Agency.

International Renewable Energy Agency. (2024). World energy transitions outlook 2024: 1.5°C pathway. International Renewable Energy Agency.

Jakob, M., Reiter, U., Krishnan, S., Louwen, A., & Junginger, M. (2020). Chapter 11—Heating and cooling in the built environment. In M. Junginger & A. Louwen (Eds.), Technological Learning in the Transition to a Low-Carbon Energy System (pp. 189–219). Academic Press. Link to source: https://doi.org/10.1016/B978-0-12-818762-3.00011-X 

Kim, B., Lee, S. H., Lee, D., & Kim, Y. (2020). Performance comparison of heat pumps using low global warming potential refrigerants with optimized heat exchanger designs. Applied Thermal Engineering, 171, 114990. Link to source: https://doi.org/10.1016/j.applthermaleng.2020.114990 

Knobloch, F., Hanssen, S. V., Lam, A., Pollitt, H., Salas, P., Chewpreecha, U., Huijbregts, M. A. J., & Mercure, J.-F. (2020). Net emission reductions from electric cars and heat pumps in 59 world regions over time. Nature Sustainability, 3(6), 437–447. Link to source: https://doi.org/10.1038/s41893-020-0488-7 

Malmquist, A., Hjerpe, M., Glaas, E., Karlsson-Larsson, H., & Lassi, T. (2022). Elderly People’s Perceptions of Heat Stress and Adaptation to Heat: An Interview Study. International Journal of Environmental Research and Public Health, 19(7), 3775. Link to source: https://doi.org/10.3390/ijerph19073775 

Mattiuzzi, C., & Lippi, G. (2020). Worldwide epidemiology of carbon monoxide poisoning. Human and Experimental Toxicology, 39(4), 387-392. Link to source: https://doi.org/10.1177/0960327119891214 

McDiarmid, H. (2023). An analysis of the impacts of all-electric heat pumps and peak mitigation technologies on peak power demand in Ontario. Ontario Clean Air Alliance. Link to source: https://www.cleanairalliance.org/wp-content/uploads/2023/12/Heat-Pump-Peak-Report-ONLINE-dec-11.pdf 

McDiarmid, H., & Parker, P. (2024). Retrofitting homes in Ontario entails significant embodied emissions: New policies needed. Climate Policy, 25(3), 388–400. Link to source: https://doi.org/10.1080/14693062.2024.2390520 

Renaldi, R., Hall, R., Jamasb, T., & Roskilly, A. P. (2021). Experience rates of low-carbon domestic heating technologies in the United Kingdom. Energy Policy, 156, 112387. Link to source: https://doi.org/10.1016/j.enpol.2021.112387 

Romanello, M., Walawender, M., Hsu, S.-C., Moskeland, A., Palmeiro-Silva, Y., Scamman, D., Ali, Z., Ameli, N., Angelova, D., Ayeb-Karlsson, S., Basart, S., Beagley, J., Beggs, P. J., Blanco-Villafuerte, L., Cai, W., Callaghan, M., Campbell-Lendrum, D., Chambers, J. D., Chicmana-Zapata, V., … Costello, A. (2024). The 2024 report of the Lancet Countdown on health and climate change: Facing record-breaking threats from delayed action. The Lancet, 404(10465), 1847–1896. Link to source: https://doi.org/10.1016/S0140-6736(24)01822-1 

Sandoval, N., Harris, C., Reyna, J. L., Fontanini, A. D., Liu, L., Stenger, K., White, P. R., & Landis, A. E. (2024). Achieving equitable space heating electrification: A case study of Los Angeles. Energy and Buildings, 317, 114422. Link to source: https://doi.org/10.1016/j.enbuild.2024.114422 

Sovacool, B. K., Evensen, D., Kwan, T. A., & Petit, V. (2023). Building a green future: Examining the job creation potential of electricity, heating, and storage in low-carbon buildings. The Electricity Journal, 36(5), 107274. Link to source: https://doi.org/10.1016/j.tej.2023.107274 

Tejani, A., & Toshniwal, V. (2023). Differential energy consumption patterns of HVAC systems in residential and commercial structures: A comparative study. International Journal of Advancements in Science & Technology, 1(3), 47–58. Link to source: https://doi.org/DOI:10.56472/25839233/IJAST-V1I3P107 

U.S. Department of Energy. (2022). Residential cold-climate heat pump technology challenge. Link to source: https://www.energy.gov/eere/buildings/articles/residential-cold-climate-heat-pump-technology-challenge-fact-sheet 

U.S. Department of Energy. (n.d.). Electric resistance heating. US Department of Energy. Link to source: https://www.energy.gov/energysaver/electric-resistance-heating 

U.S. Energy Information Administration. (2023). Updated buildings sector appliance and equipment costs and efficiencies. US Energy Information Administration. Link to source: https://www.eia.gov/analysis/studies/buildings/equipcosts/pdf/full.pdf 

Van Someren, C., Visser, M., & Slootweg, H. (2021). Impacts of electric heat pumps and rooftop solar panels on residential electricity distribution grids. 2021 IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), 01–06. Link to source: https://doi.org/10.1109/ISGTEurope52324.2021.9640090 

Wilson, E. J. H., Munankarmi, P., Less, B. D., Reyna, J. L., & Rothgeb, S. (2024a). Heat pumps for all? Distributions of the costs and benefits of residential air-source heat pumps in the United States. Joule, 8(4), 1000–1035. Link to source: https://doi.org/10.1016/j.joule.2024.01.022 

Wilson, E. J. H., Munankarmi, P., Less, B. D., Reyna, J. L., & Rothgeb, S. (2024b). Heat pumps for all? Distributions of the costs and benefits of residential air-source heat pumps in the United States. Joule, 8(4), Article 4. Link to source: https://doi.org/10.1016/j.joule.2024.01.022 

Zahiri, S., & Gupta, R. (2023). Examining the Risk of Summertime Overheating in UK Social Housing Dwellings Retrofitted with Heat Pumps. Atmosphere, 14(11), 1617. Link to source: https://doi.org/10.3390/atmos14111617 

Zhang, Q., Zhang, L., Nie, J., & Li, Y. (2017). Techno-economic analysis of air source heat pump applied for space heating in northern China. Applied Energy, 207, 533–542. Link to source: https://doi.org/10.1016/j.apenergy.2017.06.083 

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Credits

Lead Fellow

  • Heather McDiarmid, Ph.D.

Contributors

  • Stephen Agyeman, Ph.D.

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Sarah Gleeson, Ph.D.

  • Yusuf Jameel, Ph.D.

  • Daniel Jasper

  • Jason Lam

  • Cameron Roberts, Ph.D.

  • Alex Sweeney

  • Eric Wilczynski

Internal Reviewers

  • Aiyana Bodi

  • Hannah Henkin

  • Jason Lam

  • Zoltan Nagy, Ph.D.

  • Ted Otte

  • Amanda D. Smith, Ph.D.

Effectiveness

Our analysis showed that each all-electric residential heat pump for space heating reduces emissions by an average of 0.95 t CO₂‑eq/yr per dwelling (20-yr and 100-yr basis, Table 1). 

Heat pumps reduce emissions by reducing the amount of fossil fuels burned for space heating or by reducing the use of less efficient electric resistance heating. Operating a heat pump generates no on-site emissions except refrigerant leaks which are addressed by the Improve Refrigerant Management solution. Our analysis included the emissions from the electricity used to power heat pumps. Thus, the emissions reduction from heat pump adoption is expected to improve as electricity generation incorporates more renewable energy (Knobloch et al., 2020). 

There are significant regional differences in heat pump effectiveness due to the electricity mix, climate, and types of heating systems used today (Knobloch et al., 2020). The global average is weighted based on regional heating requirements and existing heating technologies. 

We did not quantify the reduction in pollutants such as NOx, SOx, and particulate matter, which are released when fossil fuels are burned for space heating. We also refrained from estimating the global warming impacts of refrigerant leaks associated with the use of heat pumps, which is addressed by our Improve Refrigerant Management solution, or natural gas leaks associated with the use of fossil fuels for heating. 

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Table 1. Effectiveness at reducing emissions from space heating.

Unit: t CO₂‑eq /heat pump/yr, 100-yr basis

mean 0.95
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Cost

A residential air-source heat pump has a mean initial installed cost of US$6,800 and an estimated US$540/yr operational cost for heating. Over a 15-yr lifespan, this results in a net cost of US$990/yr. A heat pump generally replaces both a heating and cooling system with a combined mean installed cost of US$5,300. Operating a baseline heating system costs US$830/yr (operational cooling cost not included in this analysis). Over a 15-year lifespan, the baseline case has a net cost of US$1,180/yr. This results in a net US$190 savings for households that switch to a heat pump. This translates to US$200 savings/yr/t CO₂‑eq reduced (Table 2).

These values include the average annual cost to operate the equipment for heating and the annualized upfront cost of a heat pump relative to both a heating and cooling system that it replaces. There can be significant variability in the upfront cost of equipment based on the type of heat pump installed, the size of the building, and the climate in which it is designed to operate. The cost to operate the equipment for cooling is assumed to be the same with heat pumps and the air conditioners they replace. 

There are significant regional differences in the operational cost of heating systems due to climate, utility rates, and the heating systems in use today. The global average outcomes described here are weighted averages from Europe, Canada, the United States, China, and Japan based on regional heating requirements and existing heating technologies. 

Utility cost estimates are from June 2023 (GlobalPetrolPrices, 2023) and may vary substantially over time due to factors such as volatile fossil fuel prices, changing carbon prices, and heat pump incentives. Additional installation costs, such as upgrades to electrical systems, ductwork, or radiators are not included. 

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Table 2. Cost per heat pump climate impact (2023). Negative values reflect cost savings.

Unit: US$/t CO₂‑eq /heat pump/yr, 100-yr basis

mean -200
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Learning Curve

Insufficient data exist to quantify the learning curve for heat pumps. 

The cost of installing a heat pump includes both equipment costs and the labor cost of installation. According to the U.S. Energy Information Administration (2023), retail equipment costs are 60–80% of the total installed cost of residential air-source heat pumps (central and ductless). 

Equipment costs can decrease with economies of scale and as local markets mature, but may be confounded by technological advances as well as equipment and/or refrigerant regulations that can also increase costs (IEA, 2022). European estimated learning rates for heat pump equipment costs range from 3.3% for ground-source heat pumps (Renaldi et al., 2021) to 18% for air-source heat pumps (Jakob et al., 2020). Ease and cost of installation is a research and development goal for manufacturers (IEA, 2022). 

The installed cost is also affected by rising labor costs and projected labor shortages (IEA, 2022). Renaldi et al. (2021) showed negative learning rates for the total installed costs in the United Kingdom due to increasing installation costs: -2.3% and -0.8% for air-source and ground-source heat pumps, respectively.

Heat pump manufacturers are also looking to improve the performance of the technology which may impact learning curves. In North America, the Residential Heat Pump Technology Challenge has supported the development of heat pumps with improved cold climate performance (U.S. Department of Energy [U.S. DOE], 2022). 

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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted.

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Use Heat Pumps is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere. The cumulative effect over time builds as a straight line.

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Caveats

Heat pumps can increase demands for electricity and can therefore increase demand for fossil fuel-based power generation. In areas where power generation relies heavily on fossil fuels, heat pumps may generate more emissions than gas heating systems. As the electricity sector adopts more renewables and phases out fossil fuel-based generation, the emissions impact of heat pumps will decrease. Once a building has been designed or retrofitted to accommodate a heat pump it is likely that new heat pumps will be installed at the end of equipment life, perpetuating the benefit.

Efforts are underway to retrofit buildings by improving the insulation, air-sealing and upgrading windows. When done alongside heat pump adoption, they can reduce the size of heat pump needed and increase total energy, emissions, and cost savings. 

As heat pump adoption grows, so too will the manufacture of refrigerants, some of which have high global warming potentials when they escape to the atmosphere. See Deploy Alternate Refrigerants and Improve Refrigerant Management solutions for more on accelerating change in this sector.

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Current Adoption

Our analysis suggests that 130 million heat pumps for heating are currently in operation primarily based on data in Europe, Canada, the United States, China, and Japan (Table 3). These include both all-electric heat pumps and hybrid heat pumps. The IEA (2023a) estimated that 12% of global space heating demand was met by heat pumps in 2022. 

This value is based on market reports and national data sources plus IEA estimates of total GW of installed capacity (2022). To convert installed capacity to the number of heat pumps, we used the median from the range of suggested average capacities (7.5 kW for Europe and North America, 4 kW in Japan and China, 5 kW global average). In Japan, where heat pump units typically heat only one room, we assumed 2.4 units per heat pump (International Renewable Energy Agency, 2022).

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Table 3. Current heat pump adoption level (2020-2022).

Unit: Heat pumps in operation

mean 130,000,000
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Adoption Trend

Our estimates put the average adoption trend at 15 million new all-electric and hybrid heat pumps in operation per year (see Table 4). This analysis is based on product shipment data (used as a proxy for installed heat pumps), market reports, national statistics, and IEA data for growth in installed capacity. For the IEA data (2010–2023), we assume a global average of 5 kW of heat capacity per heat pump unit (IEA, 2024).

Shipment and market analysis reports consistently show growing markets for heat pumps in much of the world (Asahi, 2023; European Heat Pump Association, 2024; IEA, 2024). In the United States, shipments of heat pumps have outnumbered gas furnaces since at least 2022 (Air-Conditioning, Heating, and Refrigeration Institute, 2025).

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Table 4. Heat pump adoption trend (2010–2023).

Unit: Heat pumps in operation/yr

25th percentile 12,000,000
mean 15,000,000
median (50th percentile) 17,000,000
75th percentile 18,000,000
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Adoption Ceiling

Our adoption ceiling is set at 1.200 billion heat pumps for space heating by 2050 (see Table 5), most of which are expected to be in residential buildings. This is based on the IEA’s Net Zero Roadmap projection that heat pumps will represent 6,500 GW of heating capacity globally by 2050, covering 55% of space heating demand (IEA, 2023a, p. 98). Our adoption ceiling assumes all-electric heat pumps cover all space heating demand. 

We assumed that average heat pump sizes (capacities) will increase over time as heat pumps cover a greater portion of a building’s heating load and as more commercial buildings with larger heating loads install heat pumps. Using a global average of 10 kW per heat pump, the IEA projections imply 650 million heat pumps will be in operation by 2050 with the technical adoption ceiling for 1,200 million heat pumps if all heating demand were met by heat pumps.

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Table 5. Heat pump adoption ceiling: upper limit for adoption level.

Unit: Heat pumps in operation by 2050

mean 1,200,000,000
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Achievable Adoption

We estimate the achievable range for heat pump adoption to be 600–960 million heat pumps in operation by 2050 (see Table 6).

Most existing space heating systems will be replaced at least once between now and 2050 because this equipment typically has lifetimes of 15–30 years (U.S. Energy Information Administration, 2023). Policies that encourage high efficiency heat pumps alongside insulation upgrades have the potential to provide lifetime savings, greater comfort, and energy efficiency benefits (Wilson et al., 2024a). Given the available timelines and potential benefits, near full adoption is technically feasible. 

We have set the high achievable heat pump adoption at 80% of the adoption ceiling to account for systems that are difficult to electrify due to very cold climates, policy, economic barriers, and grid constraints. This high achievable value assumes that some systems may be replaced before their end of life to meet climate and/or financial goals. 

We have set the low achievable heat pump adoption at 50% of the adoption ceiling. This is roughly consistent with the current adoption trend continuing out to 2050. 

Our heat pump units adopted include both all-electric and hybrid heat pumps that also rely on fuels for some heating. This analysis assumes that hybrid heat pumps will become less common with time as fuels are phased out and that all-electric heat pumps will dominate by 2050. 

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Table 6. Range of achievable adoption levels.

Unit: Heat pumps installed

Current Adoption 130,000,000
Achievable – Low 600,000,000
Achievable – High 960,000,000
Adoption Ceiling 1,200,000,000
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Our estimates show the global impact of existing heat pumps for space heating to be a reduction of 0.12 Gt CO₂‑eq/yr (100- and 20-yr basis) based on current adoption and today’s electricity grid emissions (see Table 7). Because electricity grid emissions are decreasing for each kWh of electricity generated (IEA, 2025), the actual impact will be greater than our estimates when future electricity generation emissions are lower.

For the adoption ceiling, assuming heat pumps supply all of the IEA’s projected global heating demand in 2050 (International Energy Agency, 2023a), 1.1 Gt CO₂‑eq/yr (100- and 20-yr basis) could be avoided per year with today’s electricity grid. 

A high end achievable target is 80% of the adoption ceiling, accounting for systems that may continue to use fossil fuels for heating due to factors such as cold climates, economic barriers, and grid constraints. This would result in avoiding 0.91 Gt CO₂‑eq/yr (100- and 20-yr basis) with today’s electricity grid emissions. 

A low end achievable target is 50% of the adoption ceiling, roughly equivalent to heat pump adoption continuing at today’s rate. This would result in avoiding 0.57 Gt CO₂‑eq/yr (100- and 20-yr basis) with today’s electricity grid emissions. 

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Table 7. Climate impact at different levels of heat pump adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current Adoption 0.12
Achievable – Low 0.57
Achievable – High 0.91
Adoption Ceiling 1.1
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Additional Benefits

Heat Stress

Heatwaves and extreme heat are becoming increasingly significant factors of morbidity and mortality worldwide (Romanello et al., 2024). Some buildings that replace heating systems with heat pumps will gain access to cooling (Congedo et al., 2023; Wilson et al., 2024b; Zhang et al., 2017). This can provide protection from heat stress in regions experiencing increasingly hotter summers (where air conditioning was not previously necessary) and for populations that are vulnerable to heat stress, such as the elderly (Malmquist et al., 2022). Some jurisdictions incentivize heat pumps for this reason. For example, the United Kingdom plans to install 600,000 heat pumps by 2028 (Zahiri & Gupta, 2023) and local climate adaptation plans in Canada recommend the installation of heat pumps to provide space cooling that can mitigate morbidity and mortality during heat waves (Canadian Climate Institute, 2023; City of Vancouver, n.d.). Because exposure to extreme heat is disproportionately higher for minority communities – particularly in urban environments – access to cooling has important implications for environmental justice (Benz & Burney, 2021). 

Income and Work

Installing heat pumps can lead to greater household savings on electricity. Research has shown that across the United States, heat pumps can reduce electricity bills for 49 million homes with an average savings of US$350–600 per year, depending on the efficiency of the heat pump (Wilson et al., 2024). An analysis by Wilson et al. (2024a) found that higher efficiency heat pumps could be cost-effective for about 65 million households in the United States. Heat pumps also create jobs (Sovacool et al., 2023). In its post-COVID-19 recovery plan, the IEA (2020) estimated that every US$1 million investment in heat pumps could generate 9.1 new jobs and reduce 0.8 jobs in the fossil fuel industry. About half of the new jobs will be in manufacturing, with the remaining distributed between installation and maintenance.

Health

Burning fossil fuels for heating directly emits health-harming particulates and can generate carbon monoxide. Replacing fossil gas heating with heat pumps can reduce air pollution (Carella & D’Orazio, 2021) and contribute to improving health outcomes (Zhou et al., 2022). A study in China showed that as the power grid moves to incorporate renewable energy, the air quality and health benefits of heat pumps will increasingly outweigh the benefits of gas heaters (Zhou et al., 2022). The risk of carbon monoxide poisoning also decreases in buildings that switch from fuel-burning space heating to heat pumps. In buildings that burn fuels for applications such as space heating, carbon monoxide can pose serious health risks, including poisoning and death (Mattiuzzi and Lippi, 2020). 

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Risks

Heat pumps contain refrigerants that often have high global warming potentials. Refrigerant leaks can occur during installation, operation, and end of life (McDiarmid & Parker, 2024). As more heat pumps are adopted, there is a risk of increased emissions from refrigerant leaks during operation as well as refrigerant release at the end of equipment life. Alternate refrigerants with lower global warming potentials are being phased in due to an international agreement to reduce hydrofluorocarbons, including many refrigerants (Kigali Amendment). 

Higher rates of heat pump installation will require upscaling heat pump manufacturing and training, plus certification of skilled labor to install them. Skilled labor shortages are already creating bottlenecks for heat pump adoption in some countries, some of which can be met by reskilling other heating technicians (IEA, 2022).

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Interactions with Other Solutions

Reinforcing

Advancements in heat pump technology will support the development and adoption of heat pump technology for industrial applications. 

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The increased adoption of heat pumps will increase the market for alternative refrigerants and refrigerant management.

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Competing

Alternative refrigerants require design changes (Kim et al., 2020) that may increase the upfront cost of heat pumps.

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Heat pumps may compete with alternatives such as fossil fuel-based district heating and cooling systems that lack heat pumps as well as low carbon biofuels.

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Adoption of heat pumps for space heating is likely to generate seasonal peaks in power demand during cold days that may require building out extra generating capacity that decrease grid efficiency (Bloess et al., 2018). Heat pumps can compete with electric cars for power during peak times (Van Someren et al., 2021).

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Dashboard

Solution Basics

heat pump system

t CO₂-eq (100-yr)/unit/yr
0.95
units
Current 1.3×10⁸ 06×10⁸9.6×10⁸
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.12 0.570.91
US$ per t CO₂-eq
-200
Gradual

CO₂ , CH₄, N₂O, BC

Trade-offs

Enhanced grid infrastructure will be required to support widespread building electrification and the greater demand for electricity, especially on cold days when heat pumps are less efficient at moving heat (Cooper et al., 2016). Demand side management, thermal storage, home batteries, bidirectional chargers, and greater adoption of ground-source heat pumps can all help to mitigate this increased demand (Cooper et al., 2016; McDiarmid, 2023).

In general, heat pumps have higher upfront costs relative to fueled alternatives but will save a building owner money over the lifetime of the system. This can create economic barriers to accessing the benefits of heat pumps with low-income homeowners and renters who pay for their utilities being particularly vulnerable to being left behind in the transition (Sandoval et al., 2024). Equity advocates are also concerned that the cost of maintaining gas and other fossil fuel infrastructure may increasingly fall on lower-income building owners who struggle to afford the upfront cost of electrifying with heat pumps (Davis & Hausman, 2022). 

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Action Word
Use
Solution Title
Heat Pumps
Classification
Highly Recommended
Lawmakers and Policymakers
  • Introduce zero-carbon ready building codes, clearly designating heat pumps as the default for all new buildings.
  • Incentivize purchases with grants, loans, or tax rebates.
  • Increasing training and support for heat pump installers.
  • Expand the electrical grid and increase renewable energy generation.
  • Streamline permitting processes.
  • Incentivize complementary solutions such as better insulation, thermal storage, and air sealing.
  • Institute a clean heat standard (similar to a renewable energy standard) with a well-defined implementation timeline.
  • Launch performance labels for heating technology.
  • Roll out new energy efficiency programs.

Further information:

Practitioners
  • Commit to zero-carbon construction, clearly designating heat pumps as the default for all new buildings.
  • Increase the available workforce by encouraging trade organizations to promote career and workforce development programs.
  • Design heat pumps that are simpler, faster, and cheaper to install.
  • Educate customers on the benefits and train them on usage.
  • Connect with users and early adopters to understand and adapt to consumer sentiment.
  • Create appealing incentives and financing programs.
  • Partner with builders and developers to improve product adoption and increase market demand for heat pumps.

Further information:

Business Leaders
  • Commit to zero-carbon construction, clearly designating heat pumps as the default for all new buildings.
  • Deploy heat pumps in all owned and operated facilities.
  • Encourage building owners and managers to switch to heat pumps in leased facilities.
  • Promote the benefits of heat pumps and share government incentives with leased facilities and networks.
  • Encourage employees to reduce emissions at home by providing educational resources on the benefits of domestic heat pumps.

Further information:

Nonprofit Leaders
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Deploy heat pumps in owned and operated facilities.
  • Encourage building owners and managers to switch to heat pumps in leased facilities
  • Educate businesses and communities on the benefits of installing heat pumps and any tax incentives in their region.
  • Advocate to policymakers for improved policies and incentives.
  • Educate community leaders on the need for adoption.

Further information:

Investors
  • Commit to only finance zero-carbon construction with clear requirements for heat pumps as the default for all new development investments.
  • Deploy capital to efforts that improve heat pump performance and reduce material, installation, and maintenance costs.
  • Explore investment opportunities that address supply chain concerns.
  • Consider investments that mitigate non-manufacturing barriers to scaling.
  • Finance heat pump installations via low-interest loans.

Further information:

Philanthropists and International Aid Agencies
  • Directly distribute heat pumps, prioritizing locations where heat pumps maximize emissions reductions and improve housing affordability.
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Fund R&D efforts and competitions to improve technology, reduce costs, and address supply chain concerns.
  • Support consumer advocacy and education campaigns on heat pumps and how to maximize regulatory incentives.
  • Support training or incentive programs for distributors and installers.

Further information:

Thought Leaders
  • heat pumps as the default for all new buildings.
  • Highlight the need to transition away from fossil-fuel-fired heating.
  • Educate the public on the benefits of heat pumps and how they work.
  • Provide case studies that present successes and lessons learned.
  • Increase consumer comfort by including heat pumps in communication content on topics such as home remodeling and construction, technology, health, self-sufficiency, and personal finance.
  • Provide up-to-date user information on available models.

Further information:

Technologists and Researchers
  • Identify safe, cost-effective, and suitable alternative refrigerants.
  • Design systems that require less refrigerant.
  • Work to increase the longevity of heat pumps.
  • Improve heat pumps’ efficiency and capacity at low temperatures as well as their ability to deliver higher temperature heat.
  • Research external social factors critical to adoption.
  • Identify appropriate methods for recycling and disposing of heat pumps and responsibly recovering their refrigerant chemicals at the end of the product life cycle. 

Further information:

Communities, Households, and Individuals
  • Install heat pumps when possible and encourage local HVAC retailers and installers to sell services and equipment.
  • Increase consumer comfort by sharing your experience and tips for troubleshooting technologies.
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Build support networks for new users and connect to explore innovations.
  • Encourage your property management company, employers, and government officials to accelerate adoption. 

Further information:

Sources
Evidence Base

Consensus of Effectiveness in Reducing Emissions: High

Electric heat pumps are generally viewed as the primary strategy for reducing GHG emissions from buildings. The Intergovernmental Panel on Climate Change ([IPCC] 2023) noted that heat pumps drive electrification in buildings and help decrease emissions. The European Commission (2022) claims that heat pumps are an essential way of decreasing reliance on gas in heating while increasing the use of renewable energy in the heating sector. The IEA (2022) reported that heat pumps powered by electricity generated with renewable energy “are the central technology in the global transition to secure and sustainable heating.” The International Renewable Energy Agency ([IRENA] 2024) claimed heat pumps in buildings “will play a crucial role in reducing reliance on fossil fuels.” 

In one of the largest scientific reviews on the topic, Gaur et al. (2021) concluded that heat pumps “have the potential to play a substantial role in the transition to low carbon heating,” and noted that emissions impacts of heat pumps are dependent on the type of heat pump technology, their location, and the electricity grid mix. Knobloch et al. (2020) studied 59 world regions and found that electrification of the heating sector via heat pumps will reduce emissions in most world regions where they are adopted.

The results presented in this document summarize findings from 46 reports, reviews and meta-analyses and 13 original studies reflecting current evidence from 30 countries, primarily European countries, Canada, the United States, Japan, and China. We recognize this limited geographic and technology scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions and in the commercial sector.

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