R-454B GWP and CO₂e
R-32 / R-1234yf blend — R-32/1234yf (68.9/31.1). Current. An A2L — mildly flammable — so it brings ventilation, leak-detection and safe-working requirements the A1 refrigerant it replaces did not.
Great Britain
466.3
Computed per retained Regulation (EU) No 517/2014, Annex IV, from Annex I/II component values
EU / Northern Ireland
465.2
Computed per Regulation (EU) 2024/573, Annex VI, from Annex I/II component values
These two figures genuinely differ. Use the one for the regime the equipment is in — Great Britain, or Northern Ireland under the Windsor Framework.
How this number is arrived at
R-454B is a blend, so neither regulation lists a GWP for it directly. Both set out the same method — a mass-weighted average of the components — and both list the component values in their own annexes. The arithmetic is below so you can check it rather than take it on trust.
| Component | % by mass | GWP (GB) | GWP (EU/NI) |
|---|---|---|---|
| R-32 | 68.9% | 675 | 675 |
| R-1234yf | 31.1% | 4 | 0.501 |
Great Britain: (0.689 × 675) + (0.311 × 4) = 465.075 + 1.244 = 466.3
EU / Northern Ireland: (0.689 × 675) + (0.311 × 0.501) = 465.075 + 0.156 = 465.2
Composition from ASHRAE Standard 34, as published in the ASHRAE Handbook—Fundamentals refrigerants chapter. Method from Regulation (EU) 2024/573 Annex VI and the retained GB Annex IV, which are worded identically.
Charge in kg → tonnes CO₂e
t CO₂e = charge (kg) × GWP ÷ 1,000. This figure, not the charge in kilograms, is what sets the statutory leak-check frequency.
| Charge | t CO₂e (GB) | t CO₂e (EU/NI) |
|---|---|---|
| 1 kg | 0.47 | 0.47 |
| 2 kg | 0.93 | 0.93 |
| 5 kg | 2.33 | 2.33 |
| 10 kg | 4.66 | 4.65 |
| 20 kg | 9.33 | 9.30 |
| 50 kg | 23.32 | 23.26 |
| 100 kg | 46.63 | 46.52 |
Leak-check thresholds in kg
The regulations set the bands in tonnes CO₂e. Converted to a charge of R-454B, the duty starts at these weights.
| Band | Charge (GB) | Charge (EU/NI) | Check at least | With leak detection |
|---|---|---|---|---|
| ≥5 t CO₂e | 10.7 kg | 10.7 kg | At least every 12 months | Every 24 months |
| ≥50 t CO₂e | 107 kg | 107 kg | At least every 6 months | Every 12 months |
| ≥500 t CO₂e | 1,072 kg | 1,075 kg | At least every 3 months | Every 6 months |
Automatic leak detection is mandatory at 500 tonnes CO₂e and above. Hermetically sealed equipment labelled as such is exempt below 10 tonnes CO₂e. Records must be kept for at least five years. Sources: retained Regulation (EU) No 517/2014 Articles 4–6, Regulation (EU) 2024/573 Articles 5–7, and GOV.UK guidance on checking F-gas equipment for leaks.
The two figures differ only because R-1234yf is valued differently in each regime's Annex II — 4 in GB, 0.501 in the EU and Northern Ireland. The R-32 component is identical. Note also that the widely quoted 467 comes from the ASHRAE Handbook on an AR5 basis, which is not the basis either regulation uses.
Where you meet R-454B
- •New air-cooled chillers and heat pumps replacing R-410A
- •Rooftop and packaged units of current manufacture
- •New VRF where A2L is permitted by the ventilation and safety assessment