Can I use one leak rate for all my cooling equipment, such as 15% a year?

The Intergovernmental Panel on Climate Change (IPCC) says any single composite leak rate is in doubt unless it reflects the country's mix of equipment. For one site, weight each type's range by its share (our adaptation). Its 15% default is a spreadsheet example.

What the Guidelines say

For a composite factor, the Guidelines say "the validity of any single composite emission factor must be in doubt unless it takes into consideration the particular mix of sub-applications in the country". The over-arching default of 15 percent of the bank annually is the one used "in the example of spreadsheet calculation" in the spreadsheet that came with the 2006 Guidelines. They say it is good practice to develop composite factors from research within the country.

The weighted route for one site

Where data cannot be split into the types of Table 7.9, the Guidelines say to use expert judgement to estimate each type's relative share and calculate a composite factor weighted by that share, or to use the factor for the most common type. Weighting by charge in kilograms is our choice. Work one gas at a time, never across gases.

1. Group equipment by type and add the charge for each group.
2. Take the low and high Table 7.9 rate for each type.
3. Multiply charge by rate for each group at the low end and at the high end, and add.
4. Divide each total by the total charge to get a low and a high composite rate.

250 kilograms of one gas across three types

• Split air conditioners, 40 kilograms at 1% to 10%: 0.4 to 4.0 kilograms
• Chillers, 120 kilograms at 2% to 15%: 2.4 to 18.0 kilograms
• Cold rooms (industrial refrigeration including cold storage), 90 kilograms at 7% to 25%: 6.3 to 22.5 kilograms
• Total: 9.1 to 44.5 kilograms, a composite of 9.1 / 250 = 3.6% to 44.5 / 250 = 17.8%
• A flat 15% gives 0.15 x 250 = 37.5 kilograms. On 250 kilograms of split air conditioners alone the range would be 2.5 to 25 kilograms, so the same 15% would sit above it

Charges are examples. The rates are Table 7.9 ranges from 2006, and the lower end reflects developed countries. One gas across all three types is for the arithmetic only.

What Senseible does here

Senseible reads fuel invoices and electricity bills into dated records. It does not read recovery notes, service tickets or equipment nameplates, so keep those papers yourself and add the kilograms to your Scope 1 figure.

• Leakage without top-up records
• Leak rate in food processing refrigeration
• Supermarket refrigeration leak rate

Sources: IPCC 2006 Guidelines, Volume 3, Chapter 7: Emissions of Fluorinated Substitutes for Ozone Depleting Substances

Last reviewed 2026-11-05. The 15% is an example default for national spreadsheets, not a recommended site rate. Weighting by charge is our reading.