Can Air-to-Air Heat Pumps Be the Key to Energy Efficiency and Decarbonization? Exploring Their Adoption and Potential in the UK
In the UK, air-to-air heat pumps—commonly referred to as air conditioners—are already widespread in commercial buildings, accounting for around 95% of installations in non-residential sectors. These systems are typically reversible, providing both heating and cooling through the Carnot refrigeration cycle, which transfers heat between indoor and outdoor air. Key system types include mini-split units for single rooms, multi-split systems for multiple zones, and Variable Refrigerant Flow (VRF) systems for larger commercial applications.
From a user experience perspective, modern units offer features such as smartphone-based remote control, motion-sensor-driven energy-saving modes, and individual room temperature control, making them especially suitable for older adults or single-occupancy homes.
However, widespread adoption in the residential sector faces several challenges. Stricter F-gas regulations targeting high-GWP refrigerants could soon restrict the use of the widely used R32 refrigerant. Although R290 (propane) is emerging as a promising low-GWP alternative, its flammability raises safety concerns and demands careful system design and regulatory oversight.
On the installation front, air-to-air heat pumps can be easily retrofitted into buildings without traditional wet heating systems. However, they require refrigerant piping and certified F-gas technicians, who are currently in short supply in the UK. Moreover, these systems are not yet covered by the government’s Boiler Upgrade Scheme (BUS), limiting financial incentives for homeowners.
On the innovation side, several advanced technologies are emerging. These include systems that separate dehumidification and cooling functions, semiconductor-based cooling, and solid-state heat pumps like the “ActiveWall” concept. If successfully commercialized, these innovations could deliver greater energy efficiency and lower operating costs.
Key Terms
- Air-to-Air Heat Pump: A system that heats or cools indoor air by transferring heat from outdoor air; available in ducted and ductless formats.
- F-Gas Regulations: Policies limiting the use of high global warming potential (GWP) fluorinated gases; future restrictions may apply to refrigerant R32.
- R290 (Propane): A natural, low-GWP refrigerant with minimal environmental impact, but requiring strict safety measures due to its flammability.
