F-Gas Regulations Explained for Commercial HVAC

F-Gas is the compliance signature of commercial HVAC — the one area where a facilities manager can be personally exposed to enforcement, yet the one most often left to drift because the rules feel opaque. This guide translates the GB F-Gas Regulation into plain terms: the leak-check thresholds that decide your service schedule, the certification that is legally required to touch the plant, and the refrigerant phase-down that is quietly making your R410A system more expensive to run every year.

Key takeaway upfront

Three obligations matter most. First, if your system holds 5 tonnes of CO2-equivalent of refrigerant or more, leak checks are a legal duty on a set frequency. Second, only an F-Gas certified company using certified engineers may install, service or decommission the plant. Third, the refrigerant phase-down is squeezing high-GWP gases like R410A, so new plant should be specified on low-GWP refrigerant to avoid being stranded. The Environment Agency enforces all of it, and dated figures below should be confirmed against the current position on gov.uk.

In this guide

• What F-Gas is and who regulates it
• Leak-check thresholds: 5, 50 and 500 tonnes
• How CO2-equivalent charge is calculated
• Company and engineer certification
• Record-keeping duties
• The refrigerant phase-down: R410A to R32 and R454B
• What this means for your existing plant
• What to specify on new plant
• Frequently asked questions

What F-Gas is and who regulates it {#what-is-fgas}

F-gases (fluorinated greenhouse gases) are the synthetic refrigerants used in most air conditioning, refrigeration and heat-pump equipment. They are potent greenhouse gases — R410A has a global warming potential (GWP) of around 2,088, meaning a kilogram leaked has roughly 2,088 times the warming effect of a kilogram of CO2 — so their use is controlled by law.

In Great Britain the controlling law is the GB F-Gas Regulation (the retained Fluorinated Greenhouse Gas Regulation), enforced by the Environment Agency. It sets three overlapping duties: contain refrigerant and check for leaks, use only certified companies and engineers, and reduce the overall use of high-GWP gases over time through a phase-down of supply. Defra consulted in late 2025 on tightening the GB phase-down; the direction of travel is a steeper reduction, so treat any specific future step as “confirm the current schedule on gov.uk” rather than settled.

Leak-check thresholds: 5, 50 and 500 tonnes {#thresholds}

The leak-check duty is set by the refrigerant charge, measured in tonnes of CO2-equivalent:

• 5 tonnes CO2e or more — leak check at least annually.
• 50 tonnes CO2e or more — leak check six-monthly.
• 500 tonnes CO2e or more — leak check quarterly.

Where a permanent automatic leak-detection system is fitted, some of these frequencies can be halved. The check must be carried out by a certified engineer, and any leak found must be repaired and the repair verified.

These thresholds are why so much commercial plant is in scope. Most commercial VRF systems and virtually all chillers hold enough refrigerant to cross the 5-tonne line, so leak checks are a routine legal duty for them — handled in practice through a planned maintenance contract, which is exactly why we compare planned versus reactive maintenance so bluntly: reactive-only has no mechanism to schedule a statutory check.

How CO2-equivalent charge is calculated {#co2e}

The threshold is not measured in kilograms of gas — it is measured in CO2-equivalent, which is the charge multiplied by the refrigerant’s GWP. That matters because a small charge of a high-GWP gas can cross a threshold that a larger charge of a low-GWP gas would not.

Worked example: R410A has a GWP of about 2,088. A system holding 2.4 kg of R410A holds roughly 5 tonnes of CO2-equivalent (2.4 × 2,088 ÷ 1,000 ≈ 5.0), so a modest VRF condenser can already trigger the annual leak-check duty. The same 2.4 kg of a low-GWP refrigerant like R32 (GWP 675) is only about 1.6 tonnes CO2e — below the threshold. This is one of the practical reasons low-GWP refrigerant reduces your compliance burden as well as your carbon: for a given charge, a lower GWP can keep a system under a leak-check threshold entirely.

Callout — check the maths for each system. Because the trigger is CO2-equivalent, not kilograms, you cannot judge leak-check duties by system size alone. A certified engineer calculates the CO2e charge for each system from its refrigerant type and quantity, and sets the correct check frequency.

Company and engineer certification {#certification}

It is a legal requirement that any company installing, servicing or decommissioning stationary equipment containing F-gas holds F-Gas company certification. In Great Britain that certification is issued through REFCOM, the Quidos F-Gas Register or Bureau Veritas, and it must be renewed every three years. Individual engineers handling refrigerant must also hold personal F-Gas certification.

This is not a badge of quality alone — it is a legal precondition of doing the work. Engaging an uncertified contractor to touch F-gas plant is itself a breach. REFCOM, the most widely recognised scheme, is a subsidiary of the BESA Group. When you commission VRF or chiller work, the certification of the company doing it is the first thing to verify.

Record-keeping duties {#records}

The regulation requires records to be kept for equipment subject to leak checks — refrigerant type and quantity, quantities added or recovered, the dates and results of leak checks, and the identity of the company and engineer. These records must be kept for at least five years and made available to the regulator on request. For an operator, keeping (or having your maintenance provider keep) an accurate refrigerant log is the evidence that discharges the duty. A reactive-only arrangement rarely produces these records, which is a further reason the duty pushes buildings toward planned maintenance.

The refrigerant phase-down: R410A to R32 and R454B {#phase-down}

Separate from leak checks, the phase-down steadily reduces the quantity of high-GWP F-gas that can be placed on the GB market. It does not ban existing systems outright, but it makes high-GWP refrigerant scarcer and more expensive over time — which is why re-gassing an ageing R410A system keeps getting dearer.

The direction of travel is clear. From 1 January 2025, new single-split systems under 3 kg charge could not use refrigerant of GWP 750 or more in Great Britain — a signpost for larger equipment. New plant is moving to:

• R32 (GWP 675) — the mainstream choice for new VRF and DX systems.
• R454B (GWP around 466) — increasingly specified for VRF, DX and chillers.
• R1234ze — used in some chillers.
• R290 (propane, GWP 3) — a natural refrigerant for smaller chiller and heat-pump duties, outside the F-gas quota entirely, though it carries DSEAR flammability and siting requirements.

Confirm the current phase-down steps and any equipment-specific limits on gov.uk, as this is the area most actively under review.

What this means for your existing plant {#existing-plant}

If you run R410A VRF or chillers, you do not need to panic-replace. Existing larger systems are squeezed by the phase-down, not banned. The sensible plan is:

1. Keep the system maintained and leak-tight — this keeps you compliant and slows refrigerant loss as gas gets dearer.
2. Plan replacement around natural end of life, not around a scare.
3. Budget for rising re-gas cost in the interim, so a leak becomes a decision point rather than a surprise.
4. Specify low-GWP refrigerant when you do replace.

Our comparison of VRF versus chillers and heat pump versus gas boiler both feed into that end-of-life planning.

What to specify on new plant {#new-plant}

For any new installation, specify low-GWP refrigerant so the plant is not stranded by future phase-down steps: R32 or R454B for most VRF and DX systems; R32, R454B, R1234ze or R290 for chillers depending on duty. Lower GWP also reduces the CO2-equivalent charge for a given quantity, which can keep a system under a leak-check threshold and cut your ongoing compliance burden. Where flammable natural refrigerants are used, the design must address DSEAR siting and safety. The cost guide covers how refrigerant choice feeds into project cost, and the grants and funding page covers the capital-allowance routes that fund the replacement.

Ready to plan a refrigerant transition? Request a free assessment and we will assess your system’s age, charge and condition, then give you a staged plan with real dates rather than a scare-driven rip-out.

Frequently asked questions {#faqs}

Is R410A banned?

Not outright for existing larger systems. R410A (GWP around 2,088) is being squeezed by the GB F-gas phase-down, which reduces the supply of high-GWP refrigerant over time, so R410A becomes scarcer and more expensive to buy. From 1 January 2025 new single-split systems under 3 kg could not use GWP 750-plus refrigerant, signalling the direction for larger equipment. Keep existing plant maintained and leak-tight, plan replacement at end of life, and specify low-GWP refrigerant then.

How do I know if my system needs F-Gas leak checks?

It depends on the refrigerant charge in CO2-equivalent, which is the quantity of gas multiplied by its GWP. At 5 tonnes CO2e or more the check is at least annual; 50 tonnes six-monthly; 500 tonnes quarterly. Because the trigger is CO2-equivalent rather than kilograms, a modest charge of a high-GWP gas like R410A can cross the threshold. A certified engineer calculates the figure for each system and sets the correct frequency.

Who is allowed to work on my F-Gas equipment?

Only an F-Gas certified company, using certified engineers, may legally install, service or decommission stationary equipment containing F-gas. In Great Britain that certification is issued through REFCOM, the Quidos F-Gas Register or Bureau Veritas and renewed every three years. Engaging an uncertified contractor to work on the plant is itself a breach, so verifying certification is the first thing to check when commissioning any refrigerant work.

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Authoritative references: the government’s F-gas company certification requirements on GOV.UK and REFCOM F-gas company registration.