Heat Pumps Offer Dual Climate Solution as UK Swelters
Summer heatwaves could accelerate shift from gas boilers, experts suggest
As Britain grapples with unprecedented summer heat, a home heating technology that also provides cooling is gaining attention. This dual functionality could significantly boost government ambitions to transition away from gas boilers.
A Year-Round Comfort System
For David Tester, 56, the decision to install an air-to-air heat pump in late 2022 has proven prescient. His West Sussex home has remained comfortably regulated through both the country’s freezing winter and the recent scorching heatwaves, which have brought the nation close to drought conditions.
“The heat pump has worked very well in both seasons and because I run it on electricity from my solar panels, it basically provides cooling for free,” Tester stated.
Government Backs Dual-Purpose Tech
The government is now considering including air-to-air heat pumps, capable of providing air conditioning, in its £7,500 grant scheme. Previously, the focus has been on “hydronic” heat pumps, which integrate with existing central heating systems.
Hydronic systems function like refrigerators in reverse, using electricity to extract and amplify ambient heat to warm water circulated through radiators. However, air-to-air systems are globally dominant, according to Jan Rosenow, a programme director at the Regulatory Assistance Project.
“In most homes across Europe air-to-air heat pumps are the most popular option. We see the same thing in China, and the same in the US. It may seem new for UK homes, but really it is the dominant technology,”
—Jan Rosenow, Programme Director at Regulatory Assistance Project
Air-to-Air: A Growing UK Presence
These air-heating units are already being deployed in UK public buildings and commercial spaces. Andrew Sissons, deputy director at Nesta, believes smaller homes and flats will particularly benefit from combined heating and cooling.
Air-to-air heat pumps heat air directly and use a refrigerant for cooling in the summer. “Demand for air-to-air heat pumps could be significant,” Sissons commented. “They provide cooling – which is more in demand as our summers get hotter – and the cost of units is far lower too. They are also relatively simple to install because they are usually wall mounted so they don’t require as much outdoor space.”
A key limitation is that these systems typically do not provide hot water, necessitating a separate low-carbon solution for that requirement.
Tester continues to use his gas boiler for hot water in his underfloor heating, but sparingly. The air-to-air unit handles most of his home’s heating needs, running on solar power for cooling in the summer.
Addressing Cooling Concerns
The increasing use of air conditioning in Britain raises concerns about energy demand and carbon targets. The International Energy Agency has warned that rising cooling needs could strain electricity grids, projecting a doubling of global electricity demand for cooling by 2050.
However, Sissons argues that British households need not worry about the carbon impact of cooling. He points to the significantly lower number of cooling days compared to heating days, where heat pumps offer substantial carbon savings over gas boilers. The UK’s increasingly green electricity grid further mitigates the carbon footprint of cooling.
Furthermore, peak cooling demand often coincides with high solar power generation. According to the UK’s National Energy System Operator, the grid is expected to be virtually zero carbon by the end of the decade, capable of meeting increased demand from electric vehicles, heat pumps, and data centres.
To manage potential surges in demand, the Energy Saving Trust advises utilising passive cooling methods like window shades and improved ventilation before relying on active cooling systems. A recent report indicated that in 2023, gas boiler installations in the UK outnumbered heat pumps by a significant margin of 15 to one, highlighting the scale of the transition ahead (The Guardian, April 2025).
