Refrigerant leakage: how to calculate F-gas emissions

Air conditioning, heat pumps, chillers and refrigeration all contain refrigerant, and all of them leak a little. Many refrigerants are fluorinated gases with global warming potentials in the thousands, so a few kilograms can be one of the largest items in a small company's Scope 1. The Corporate Standard counts these as fugitive emissions, from "intentional or unintentional releases". See Scope 1 emissions.

Estimating what leaked

You rarely measure a leak directly. The practical estimate is the mass of refrigerant added during servicing: if a technician tops a system up with 1.5 kg, about 1.5 kg escaped since the last service. Ask your maintenance contractor for a log per system with dates and kilograms added.

Other cases to include:

• Equipment disposed of without recovering the refrigerant.
• Accidental releases during repairs.
• New installations where charging losses are recorded.

Factors for common refrigerants

DESNZ 2026 factors, kg CO2e per kg released ("total emissions including non-Kyoto products" column):

The spread is enormous: a kilogram of R404A counts as almost 4 tonnes of CO2e, a kilogram of propane as 60 grams.

Worked example

A shop's service log for the year shows 2.0 kg of R404A added to the cold room and 1.2 kg of R410A added to the air conditioning:

• 2.0 × 3,943 = 7,886 kg CO2e
• 1.2 × 1,924 = 2,309 kg CO2e
• Total: 10,195 kg CO2e, about 10 tonnes from 3.2 kg of gas.

Kyoto and non-Kyoto gases

DESNZ gives two columns for some refrigerants: emissions "including only Kyoto products" and "total emissions including non-Kyoto products". Older refrigerants such as R22 are controlled under the Montreal Protocol rather than the Kyoto Protocol. Corporate GHG inventories based on the GHG Protocol cover the Kyoto gases; if you also report non-Kyoto gases, show them separately and say so.

Reducing refrigerant emissions

The result depends on two things you can manage: how much leaks (maintenance, leak detection) and what the gas is (replacing high-GWP refrigerants when equipment is replaced). Recording kilograms per system each year shows which units leak most.