Heat Pump Refrigerant Guide: R32 vs R290 for UK Installations

Heat Pump Refrigerant Guide: R32 vs R290 for UK Installations

The refrigerant inside a heat pump is fundamental to its efficiency, environmental impact and long-term serviceability. As UK heat pump installations accelerate — driven by the Boiler Upgrade Scheme (BUS) and the push to decarbonise home heating — understanding the differences between R32 and R290 is increasingly important for installers and consumers alike.

R32 in UK Heat Pumps

R32 (GWP 675) is the current dominant refrigerant in UK air source heat pumps. It offers:

• Good thermodynamic efficiency: High COP values across UK operating temperatures
• Lower GWP than R410A: 675 vs 2,088 — roughly one third
• Widely available: Stocked by UK F-Gas compliant suppliers for servicing
• A2L classification: Mildly flammable — requires compliant installation and service procedures
• Established supply chain: All major UK heat pump brands (Mitsubishi, Daikin, Samsung, LG, Vaillant) offer R32 models

R290 (Propane) in UK Heat Pumps

R290 (propane, GWP 3) is a natural refrigerant with exceptional thermodynamic performance. It is gaining market share in the UK, particularly in high-efficiency models and those with lower refrigerant charges. Key points:

• Ultra-low GWP: GWP of 3 — essentially carbon-neutral from a direct emissions perspective
• A3 classification: Highly flammable — requires specialist A3-rated equipment and training for installation and servicing
• High COP: Excellent performance particularly at low ambient temperatures — well suited to UK climate
• Smaller charge: Modern R290 heat pumps use very small charges (typically 0.5–1.5 kg) due to improved heat exchanger design
• Future-proof: No F-Gas phase-down risk; expected to dominate new heat pump installations from 2030

R32 vs R290 for UK Installers: Practical Considerations

• Tooling: R32 uses standard HFC tools (A2L-rated). R290 requires A3-specific explosion-proof equipment
• Training: R290 handling requires additional A3 refrigerant training beyond standard F-Gas Cat I
• Service availability: R32 is more widely available from UK suppliers today; R290 infrastructure is growing
• Regulations: Both comply with current UK F-Gas rules; R290’s near-zero GWP means no phase-down pressure

Need R32 for heat pump servicing? Order R32 9 kg from Refrigerant Gas Supplies Ltd — next-day delivery across mainland UK. Browse our full refrigerant range.

Frequently Asked Questions

Does a UK air source heat pump use R32 or R290?

Most current UK ASHPs use R32. R290 is increasingly used in newer high-efficiency models. Check the unit’s data plate to confirm. Both are F-Gas compliant for UK use.

Is R32 safe for UK domestic heat pumps?

Yes. R32 is approved for domestic use under BS EN 378. Installers must comply with A2L charge weight limits (typically 1.25 kg per occupied space). Most domestic heat pumps are within this limit.

Can heat pump refrigerant be topped up if it leaks?

Only after the leak is found and repaired — UK F-Gas rules prohibit charging a leaking system. All top-up work must be done by an F-Gas certified engineer.