Air-source heat pumps can heat homes using cold outside air and achieve up to five times the efficiency of conventional gas boilers [1].
This shift in home heating technology is critical for reducing reliance on fossil-fuel gas boilers. By utilizing low-carbon energy to move heat rather than generate it through combustion, these systems provide a scalable path toward decarbonizing residential heating.
Matt Lipson, a researcher at Undaunted at Imperial College's clean-tech innovation hub, said the process through a presentation by the Royal Institution. He said air-source heat pumps can deliver up to five units of heat for every unit of electricity they use [1]. This efficiency is rooted in 200-year-old thermodynamic principles that allow the system to extract thermal energy from the environment, even when the air feels cold to humans.
While some critics suggest that certain models struggle in harsh winters, data from cold-climate regions indicates high reliability. Heat pumps have been proven to work in sub-zero temperatures across Northern Europe, delivering comfortable indoor heat while cutting energy bills, a DW Climate Correspondent said [3]. Some systems are reported to operate reliably down to at least –25 °C [3].
Recent testing further supports the viability of these systems in extreme conditions. Sofia Quaglia said that in tests, modern cold-climate heat pumps achieved a coefficient of performance of around four even at –20 °C [2]. This means the systems continue to move significant amounts of heat into the home despite the extreme external cold.
The technology is being deployed across diverse geographies, from the Royal Institution building in London to homes in Northern Europe and the U.S. [1, 3]. This widespread application demonstrates that the physics of heat transfer can overcome the limitations of traditional heating methods in various climates.
“Air-source heat pumps can deliver up to five units of heat for every unit of electricity they use.”
The transition to air-source heat pumps represents a fundamental shift from burning fuel to moving energy. By proving that these systems remain efficient at temperatures as low as –20 °C to –25 °C, the technology removes the primary argument against its use in northern latitudes, potentially accelerating the phase-out of residential gas infrastructure.
