If you’re an HVAC engineer or facility manager in the UK, you’ve almost certainly been asked the question: should I be using R32 or R410A? The short answer is: R32 for all new installations, R410A only for servicing existing systems. But the full picture matters — this guide covers everything you need to know about both refrigerants, how they compare, and what the UK F-Gas regulations mean for your business.
R32 vs R410A at a Glance
Before diving into the detail, here’s a head-to-head comparison of the two refrigerants that dominate UK air conditioning.
| Property | R32 | R410A |
|---|---|---|
| GWP (AR5) | 675 | 2,088 |
| ODP | 0 | 0 |
| Safety class | A2L (mildly flammable) | A1 (non-flammable) |
| Boiling point at 1 bar | −51.7°C | −51.6°C |
| Critical pressure | 57.8 bar | 49.0 bar |
| Composition | Single component (HFC-32) | Zeotropic blend (R32/R125 50:50) |
| Status in UK 2025 | Preferred for all new AC | Service use only (existing systems) |
| F-Gas phase-down impact | Low (GWP 675) | High (GWP 2,088) |
| Cylinder (Refrigerant Gas Supplies Ltd) | 9 kg refillable | 10 kg refillable |
What Is R32?
R32 (difluoromethane, HFC-32) is a single-component HFC refrigerant with a Global Warming Potential of 675 — roughly one third of R410A’s GWP of 2,088. It was commercialised as a refrigerant by Daikin in 2012 and is now the standard refrigerant for virtually all new residential and commercial split AC systems sold in the UK.
R32 operates at higher pressures than R410A, which means it can achieve the same cooling capacity with less refrigerant charge — typically 20–30% less by weight. This makes it more efficient per unit of cooling and reduces the total F-Gas quota consumed per installation.
R32 Safety: Understanding A2L
R32 is classified A2L under EN 378 and ISO 817 — this means it is mildly flammable. “A” means low toxicity; “2L” means slightly flammable with a slow burning velocity (less than 10 cm/s at 23°C). In practice, R32 requires A2L-compliant equipment and installation practices, but poses no unusual danger when handled correctly.
UK F-Gas Category I or II certification is required to purchase and handle R32. Engineers moving from R410A systems should be familiar with EN 378 Part 1 requirements for A2L refrigerants before handling R32.
What Is R410A?
R410A is a zeotropic blend of R32 (50%) and R125 (50%), first commercialised in the late 1990s as a replacement for the HCFC R22. It rapidly became the dominant refrigerant in residential and commercial AC worldwide. R410A is A1 (non-flammable) and operates at high pressures, requiring robust piping and components.
As a zeotropic blend, R410A can fractionate — meaning the blend composition can change if refrigerant leaks as a gas. For this reason, R410A should always be charged as a liquid. It also has a GWP of 2,088, placing it firmly in the crosshairs of UK and EU F-Gas phase-down regulations.
F-Gas Phase-Down: Why R410A Is Being Restricted
The UK F-Gas Regulation (retained from EU Regulation 517/2014) implements a quota-based phase-down of fluorinated gases with high GWPs. The phase-down works by reducing the total CO₂-equivalent quantity of F-Gases that can be placed on the UK market — meaning gases with higher GWPs have reduced quota allocations over time.
R410A (GWP 2,088) consumes approximately three times more quota than R32 (GWP 675) for the same kilogram quantity. This means:
- New AC equipment manufacturers switched to R32 to remain viable under quota restrictions
- R410A supply for service use will tighten as phase-down quotas reduce annually
- R410A prices are likely to rise in real terms as the phase-down continues
- R32 — with its lower GWP — is significantly less affected by the phase-down
For UK HVAC engineers, this means: if you’re installing new equipment today, R32 is the only sensible choice. For servicing the large existing installed base of R410A systems, R410A remains available from F-Gas compliant suppliers including Refrigerant Gas Supplies Ltd.
R32 vs R410A: Technical Differences That Matter
Pressure
R32 operates at higher pressures than R410A. At typical AC operating conditions, R32 discharge pressures run around 10–15% higher than R410A. This means R32 systems use components rated for higher pressures. Never use R32 in equipment designed only for R410A — the pressure differential can cause component failure.
Refrigerant Charge
R32 typically requires 20–30% less refrigerant charge by weight compared to R410A in equivalent-capacity systems. A typical 3.5 kW split system designed for R32 might require 550–700g of refrigerant vs 700–900g for R410A. This lower charge reduces F-Gas quota consumption and lowers refrigerant costs per installation.
Energy Efficiency
Modern R32 systems typically achieve higher seasonal energy efficiency ratios (SEER/SCOP) than equivalent R410A equipment, owing to the thermophysical properties of R32 and improvements in compressor technology since the transition. In the UK’s MCS and RHI frameworks, R32 equipment is well-supported by all major manufacturers.
Oil Compatibility
Both R32 and R410A systems use POE (polyolester) oils. However, the specific viscosity grade may differ between R32 and R410A systems. Always follow the manufacturer’s specification for oil type and grade — using the wrong oil can void warranty and affect system reliability.
Can R32 Replace R410A in an Existing System? No.
This question comes up regularly. The answer is no — R32 cannot be retrofitted into a system designed for R410A, and vice versa. Key reasons:
- Different pressures: R32’s higher operating pressures can overstress R410A-rated components
- Different safety classification: A2L equipment requirements (leak detection, ventilation) differ from A1 installations
- Compressor compatibility: R32 and R410A compressors use different refrigerant flow rates and oil specifications
- Regulatory compliance: Charging an R410A system with R32 constitutes an illegal refrigerant substitution under UK F-Gas regulations
If you have existing R410A equipment that needs topping up, you need R410A from a compliant UK supplier. If you’re installing new equipment, specify R32-rated systems and stock R32 from Refrigerant Gas Supplies Ltd.
Which Refrigerant Should You Stock in 2025?
For most UK HVAC businesses operating in 2025, the answer is: both.
- R32 (9 kg cylinder): Your primary stock for new installations. All new residential and commercial split systems use R32. Ensure your engineers are trained for A2L handling.
- R410A (10 kg cylinder): Stock for servicing the large installed base of R410A equipment. Demand will persist for 10–15+ years given the volume of R410A systems in service across the UK.
Refrigerant Gas Supplies Ltd supplies both gases with next-day mainland UK delivery. Call +44 7988 028925 for trade pricing and bulk orders.
Frequently Asked Questions
Can I use R32 in a system designed for R410A?
No. R32 and R410A are not interchangeable. They have different pressures, oil requirements and safety classifications. R32 must only be used in systems specifically designed and approved for R32. Never mix refrigerants or retrofit without manufacturer approval.
Is R32 cheaper than R410A in the UK?
Pricing varies by supplier and quantity, but R32 is generally competitively priced. As R410A supply tightens under F-Gas phase-down, R410A prices are expected to rise. Refrigerant Gas Supplies Ltd offers trade pricing on both gases.
Which refrigerant do UK AC manufacturers use in 2025?
All major UK and global AC manufacturers — Daikin, Mitsubishi Electric, Fujitsu, Samsung, LG, Panasonic and others — have standardised on R32 for new residential and light commercial split AC systems. R410A is retained only for legacy/replacement parts.
How long will R410A still be available in the UK?
R410A remains available for servicing existing installations under UK F-Gas phase-down. There is no immediate ban on R410A for service use, but supply will tighten as quota allocations reduce annually. Refrigerant Gas Supplies Ltd maintains compliant stock for service engineers.