Mandatory documented leak checks apply to air conditioning and refrigeration equipment according to how much damage would be caused to the atmosphere if the whole refrigerant charge were released.
The frequency of those inspections is set by the global warming potential (GWP) of the refrigerant multiplied by the estimated volume held in each individual system. That gives the CO₂ equivalent figure — the CO₂e — on which everything else depends.
How often does a system need leak checking?
Where a system contains:
- 5 to 50 tonnes CO₂e — one inspection per year
- 50 to 500 tonnes CO₂e — an inspection every six months
- More than 500 tonnes CO₂e — quarterly inspections
The leak checking frequency can be halved where a permanent leak detection system is fitted. Permanent leak detection is mandatory in its own right for charges of 500 tonnes CO₂e and above.
The thresholds for common refrigerants
- R410A (GWP 2,088) — more than 2.39kg once a year, 23.9kg twice a year, more than 239kg four times a year
- R407C (GWP 1,774) — more than 2.81kg once a year, 28.1kg twice a year, more than 281kg four times a year
- R404A (GWP 3,922) — more than 1.27kg once a year, 12.7kg twice a year, more than 127kg four times a year
- R134a (GWP 1,430) — more than 3.49kg once a year, 34.9kg twice a year, more than 349kg four times a year
For any other refrigerant, divide 5,000 by its GWP to get the weight at which the first inspection is required, then move the decimal point one place to the right for each step up.
Calculating carbon loading
Some clients ask for the carbon loading of an air conditioning or refrigeration system, particularly if they hold ISO 14001 accreditation. It is a straightforward calculation: refrigerant GWP multiplied by total refrigerant charge.
A system holding 25kg of R410A therefore has a carbon loading of 52,200kg — 25 × 2,088. That is 52.2 tonnes, so two documented leak checks per year are required.
Labelling
Since 1 January 2017, any product containing F gases placed on the market must carry a label stating the quantity of F gas in the equipment expressed both by weight and in CO₂ equivalent, together with the global warming potential of the gas.
Where to check the current position
Great Britain now runs its own F gas regime rather than the EU regulation the rules originated in, so always work from the current published guidance rather than an older summary:
- Calculate the carbon dioxide equivalent quantity of an F gas — GOV.UK
- F gas guidance for users, producers and traders — GOV.UK
- F Gas information sheets — Gluckman Consulting
If you are unsure which category your plant falls into, or you want your leak checking put on a documented schedule, our F gas qualified engineers can survey the site and set the intervals for you.
