F-Gas Calculator — CO₂ Equivalent & Leak Checks

CO₂ equivalent expresses the global warming potential of a refrigerant charge in terms of how many tonnes of CO₂ would have the same warming effect. It’s calculated as: charge (kg) × GWP ÷ 1000 = tonnes CO₂e. For example, 3.5 kg of R410A (GWP 2088) = 7.3 tCO₂e.

Under the F-Gas Regulation (retained in GB law post-Brexit, Reg 517/2014 Art.4-5): below 5 tCO₂e = no mandatory checks, 5-50 tCO₂e = annual checks (or every 24 months with a leak detection system), 50-500 tCO₂e = six-monthly checks (or annual with leak detection), 500 tCO₂e or more = quarterly checks. At 500 tCO₂e or more an automatic leak detection system is mandatory (not optional); once fitted the check interval becomes six-monthly, and the detection system itself must be checked at least every 12 months.

R410A = 2088 (most common current ASHP refrigerant), R32 = 675 (increasingly used in new heat pumps), R290 (propane) = 3 (very low GWP, growing in use), R134a = 1430 (older systems). The industry is transitioning to lower-GWP options under the F-Gas phase-down schedule. Use our Heat Pump Sizing Calculator to size a heat pump system.

For systems containing 5+ tCO₂e, you must maintain an F-Gas logbook recording: refrigerant type and quantity, dates and results of leak checks, any refrigerant added or recovered, the identity of the certified technician, and details of any leaks found and repaired.

Only personnel holding a valid F-Gas certificate (Category I-IV as appropriate) can install, maintain, service, repair, or decommission F-Gas equipment. Companies must hold an F-Gas company certificate. This applies to air conditioning, heat pumps, and refrigeration systems containing fluorinated greenhouse gases.