Grant UK launched the Aerona 290 air source heat pump in 2024, its fifth generation heat pump and the first in its range to use R290 refrigerant rather than the more commonly used R321. The company describes the launch as "an exciting milestone" and says the unit "showcases the latest innovation in low carbon heating technology"1. The blog announcing the range was updated on 15 May 20251.
R290, also known as propane, is a natural refrigerant. Grant UK states it has a global warming potential (GWP) of 3, against 675 for R32, and zero ozone depletion potential1. The company says the Aerona 290 requires less refrigerant by volume than a typical R32 heat pump1. It reports an ErP rating of A+++ at 35°C flow temperature and states the unit is designed to operate at outdoor temperatures as low as -25°C1. Each unit works with the Aerona Smart Controller, which supports control through a mobile app and remote monitoring for installers1.
Grant UK sets out the main differences between the two refrigerants:
| Aerona 290 (R290) | Aerona³ R32 | |
|---|---|---|
| Refrigerant GWP | 3 | 675 |
| Unit size | Generally larger, with larger clearances required | Compact design |
| Best suited to | Homes where sustainability is the priority | Homes where outdoor space is limited |
Source: Grant UK1
Grant UK states that R290 is more flammable than other refrigerants, and that R290 units are generally larger and require larger clearances because of additional safety requirements for installation and siting1. It says installation involves additional safety clearances and guidelines that must be followed, and that a qualified professional should carry out the work in line with current regulations1. The company says R290 heat pumps are suitable for a wide variety of homes, from new builds to period properties and retrofit installations, but work most efficiently in well insulated homes1.
Both the Aerona³ R32 and Aerona 290 ranges are MCS certified, which makes them eligible for Boiler Upgrade Scheme funding1. Grant UK states that homeowners in England and Wales can receive a grant of up to £7,500 when replacing an existing fossil fuel boiler with a low carbon air source heat pump1. The Grant Aerona 290 heat pump sits alongside the company's earlier Grant heat pumps: Aerona air source range, and the choice between refrigerants is set out in more detail in Heat Pump Refrigerants: R290, R32 and the F-Gas Rules.
Why it matters for households
The refrigerant inside a heat pump does not change how the heating system works in the home, but it affects the unit's environmental footprint and, in this case, its physical size. A GWP of 3 against 675 means a far smaller global warming impact if refrigerant is lost over the life of the unit1. The trade-off reported by Grant UK is space: R290 units are generally larger and need larger clearances, which matters for homes with limited outdoor room, where the compact R32 models are described as better suited1. For a household weighing up heat pump vs biomass boiler or comparing Heat Pump Manufacturers Supplying UK Homes, the practical questions remain the same: heat loss, insulation, hot water demand and a compliant siting position1. Grant UK notes that a R290 heat pump works most efficiently in a well insulated home1.
What happens next
No future product dates, prices or availability timelines are given in the source. Grant UK directs readers to its installer search and to its guidance on planning a heat pump installation1.
Sources1 cited
- What are the benefits of R290 heat pumps? | Grant UK, grantuk.com