IN SUMMARY
Matching a heat pump's clean operation with cleaner manufacturing
Matching a heat pump's clean operation with cleaner manufacturing
Heat pumps are established as a low-carbon alternative to gas boilers, with Gemserv’s research finding a gas boiler generates 55% more emissions in use than a 10kW air source heat pump. But the emissions embodied in making a heat pump are increasingly under scrutiny from regulators, investors and customers. Minviro and Gemserv ran a cradle-to-gate life cycle assessment of a 10kW air source heat pump to measure those embodied emissions, identify the hotspots, and show how far they can be reduced.
Heat pumps are established as a low-carbon alternative to gas boilers, with Gemserv’s research finding a gas boiler generates 55% more emissions in use than a 10kW air source heat pump. But the emissions embodied in making a heat pump are increasingly under scrutiny from regulators, investors and customers. Minviro and Gemserv ran a cradle-to-gate life cycle assessment of a 10kW air source heat pump to measure those embodied emissions, identify the hotspots, and show how far they can be reduced.
Heat pumps are established as a low-carbon alternative to gas boilers, with Gemserv’s research finding a gas boiler generates 55% more emissions in use than a 10kW air source heat pump. But the emissions embodied in making a heat pump are increasingly under scrutiny from regulators, investors and customers. Minviro and Gemserv ran a cradle-to-gate life cycle assessment of a 10kW air source heat pump to measure those embodied emissions, identify the hotspots, and show how far they can be reduced.
Manufacturing carries a real carbon cost. A 10kW air source heat pump made with standard modern methods has 640 kg CO₂e of embodied emissions, before its clean in-use performance is counted.
Manufacturing carries a real carbon cost. A 10kW air source heat pump made with standard modern methods has 640 kg CO₂e of embodied emissions, before its clean in-use performance is counted.
Manufacturing carries a real carbon cost. A 10kW air source heat pump made with standard modern methods has 640 kg CO₂e of embodied emissions, before its clean in-use performance is counted.
Better choices nearly halve it. Switching to lower-carbon steel, recycled insulation and a lower-GWP refrigerant cuts embodied emissions by 46.8%, to 340 kg CO₂e.
Better choices nearly halve it. Switching to lower-carbon steel, recycled insulation and a lower-GWP refrigerant cuts embodied emissions by 46.8%, to 340 kg CO₂e.
Better choices nearly halve it. Switching to lower-carbon steel, recycled insulation and a lower-GWP refrigerant cuts embodied emissions by 46.8%, to 340 kg CO₂e.
Four hotspots dominate. Steel production, tube insulation, on-site manufacturing electricity and refrigerant choice account for the bulk of the footprint, and each offers a clear reduction pathway.
Four hotspots dominate. Steel production, tube insulation, on-site manufacturing electricity and refrigerant choice account for the bulk of the footprint, and each offers a clear reduction pathway.
Four hotspots dominate. Steel production, tube insulation, on-site manufacturing electricity and refrigerant choice account for the bulk of the footprint, and each offers a clear reduction pathway.
Why manufacturing emissions matter for heat pumps
The case for heat pumps rests on their in-use performance, and that case is strong: a gas boiler generates 55% more emissions in operation than a comparable 10kW air source heat pump. But as clean technologies scale, attention is shifting to their whole-life footprint, including the materials and energy used to build them. The consequences of ignoring this are visible across the wider sector, from landfilled first-generation wind turbines to water stress from lithium mining. Regulation is following, with the Ecodesign for Sustainable Products Regulation, the Corporate Sustainability Reporting Directive and the EU and UK Taxonomies all drawing on life cycle thinking. For heat pump makers, the in-use savings are only fully realised if manufacturing is decarbonised too.
The case for heat pumps rests on their in-use performance, and that case is strong: a gas boiler generates 55% more emissions in operation than a comparable 10kW air source heat pump. But as clean technologies scale, attention is shifting to their whole-life footprint, including the materials and energy used to build them. The consequences of ignoring this are visible across the wider sector, from landfilled first-generation wind turbines to water stress from lithium mining. Regulation is following, with the Ecodesign for Sustainable Products Regulation, the Corporate Sustainability Reporting Directive and the EU and UK Taxonomies all drawing on life cycle thinking. For heat pump makers, the in-use savings are only fully realised if manufacturing is decarbonised too.
How the study was built
Minviro conducted a cradle-to-gate LCA with a functional unit of one 10kW air source heat pump ready for shipping, covering raw material extraction through to manufacturing. Transport, the use phase and end-of-life were excluded so the focus stayed on the materials and processes of production. The bill of materials drew on established academic studies, with background data from Ecoinvent 3.10 and the Environmental Footprint 3.1 method, focused on climate change potential. Importantly, the base model uses global average emission factors for all inputs, making the results location-agnostic. They are an illustrative example for discussing reduction opportunities rather than a figure for any one product, since every supply chain differs and any product-specific claim needs its own regionally representative LCA.
Minviro conducted a cradle-to-gate LCA with a functional unit of one 10kW air source heat pump ready for shipping, covering raw material extraction through to manufacturing. Transport, the use phase and end-of-life were excluded so the focus stayed on the materials and processes of production. The bill of materials drew on established academic studies, with background data from Ecoinvent 3.10 and the Environmental Footprint 3.1 method, focused on climate change potential. Importantly, the base model uses global average emission factors for all inputs, making the results location-agnostic. They are an illustrative example for discussing reduction opportunities rather than a figure for any one product, since every supply chain differs and any product-specific claim needs its own regionally representative LCA.
What the results show
The base scenario puts the embodied footprint of a standard 10kW air source heat pump at 640 kg CO₂e, with four clear hotspots. Steel is the largest, because blast furnace ironmaking emits around 2 kg CO₂e per kg of iron ore processed across the reinforcing and low-alloyed steel used. Tube insulation is next, driven by the elastomer and steam-cracked polymers it contains, at roughly 1.5 kg CO₂e per kg of polymer. On-site manufacturing electricity accounts for around a fifth of the total, and the refrigerant, modelled as global-average R134a, is a sensitivity because its impact varies widely by production method and location. Re-running the model with lower-carbon steel, recycled insulation and a lower-GWP refrigerant brings the total down to 340 kg CO₂e, a 46.8% reduction, after which manufacturing electricity becomes the dominant remaining hotspot.
The base scenario puts the embodied footprint of a standard 10kW air source heat pump at 640 kg CO₂e, with four clear hotspots. Steel is the largest, because blast furnace ironmaking emits around 2 kg CO₂e per kg of iron ore processed across the reinforcing and low-alloyed steel used. Tube insulation is next, driven by the elastomer and steam-cracked polymers it contains, at roughly 1.5 kg CO₂e per kg of polymer. On-site manufacturing electricity accounts for around a fifth of the total, and the refrigerant, modelled as global-average R134a, is a sensitivity because its impact varies widely by production method and location. Re-running the model with lower-carbon steel, recycled insulation and a lower-GWP refrigerant brings the total down to 340 kg CO₂e, a 46.8% reduction, after which manufacturing electricity becomes the dominant remaining hotspot.
How manufacturers can cut the footprint
Each hotspot has a route to reduction. Steel’s carbon intensity can be cut by up to around 70% through renewable-powered electric arc furnaces, more direct reduced iron using hydrogen, or higher scrap feedstock. Insulation impact can be roughly halved using recycled plastic. Refrigerant choice matters both for carbon and compliance, with lower-GWP options such as R290 available and bans on R134a already scheduled, which will force change regardless. Together these choices cut the heat pump’s footprint by between a third and a half, before any switch to renewable manufacturing energy on-site, which would deliver more still. The wider point is that LCA pinpoints exactly where the impact sits, so manufacturers can target sourcing decisions with data rather than guesswork, support EPDs and verifiable claims, and stay ahead of tightening regulation.
Each hotspot has a route to reduction. Steel’s carbon intensity can be cut by up to around 70% through renewable-powered electric arc furnaces, more direct reduced iron using hydrogen, or higher scrap feedstock. Insulation impact can be roughly halved using recycled plastic. Refrigerant choice matters both for carbon and compliance, with lower-GWP options such as R290 available and bans on R134a already scheduled, which will force change regardless. Together these choices cut the heat pump’s footprint by between a third and a half, before any switch to renewable manufacturing energy on-site, which would deliver more still. The wider point is that LCA pinpoints exactly where the impact sits, so manufacturers can target sourcing decisions with data rather than guesswork, support EPDs and verifiable claims, and stay ahead of tightening regulation.