ANNEX VI
Method of calculating the GWP referred to in Article 3, point (1), of a mixture
The GWP of a mixture is calculated as a weighted average, derived from the sum of the weight fractions of the individual substances multiplied by their GWP, unless otherwise specified, including substances that are not fluorinated greenhouse gases.
Σ (Substance × % × GWP) + (Substance Y % × GWP) + … (Substance N % × GWP), where % is the contribution by weight with a weight tolerance of +/– 1 %.
For example: applying the formula to a mixture of gases consisting of 60 % dimethyl ether, 10 % HFC-152a and 30 % isobutane:
Σ (60 % × 1) + (10 % × 124) + (30 % × 0) |
Total GWP = 13,0 |
The GWP of the following non-fluorinated substances are used to calculate the GWP of mixtures. For other substances not listed in this annex a default value of 0 applies. Only emissible components that fulfil broadly the same function are relevant for the calculation of the GWP.
Substance | GWP 100 (1) | ||
Common name | Industrial designation | Chemical Formula | |
methane | CH4 | 27,9 | |
nitrous oxide | N2O | 273 | |
dimethyl ether | CH3OCH3 | 1 (2) | |
methylene chloride | CH2Cl2 | 11,2 | |
methyl chloride | CH3Cl | 5,54 | |
chloroform | CHC13 | 20,6 | |
ethane | R-170 | CH3CH3 | 0,437 |
propane | R-290 | CH3CH2CH3 | 0,02 |
butane | R-600 | CH3CH2CH2CH3 | 0,006 |
isobutane | R-600a | CH(CH3)2CH3 | 0 (3) |
pentane | R-601 | CH3CH2CH2CH2CH3 | 0 (3) |
isopentane | R-601a | (CH3)2CHCH2CH3 | 0 (3) |
ethoxyethane (diethyl ether) | R-610 | CH3CH2OCH2CH3 | 4 (2) |
methyl formate | R-611 | HCOOCH3 | 11 (4) |
hydrogen | R-702 | H2 | 6 (2) |
ammonia | R-717 | NH3 | 0 |
ethylene | R-1150 | C2H4 | 4 (2) |
propene | R-1270 | C3H6 | 0 (3) |
cyclopentane | C5H10 | 0 (3) | |
(1) Based on the Sixth Assessment Report adopted by the Intergovernmental Panel on Climate Change, unless otherwise indicated.
(2) Based on the Fourth Assessment Report adopted by the Intergovernmental Panel on Climate Change.
(3) WMO et al. (2018). Scientific Assessment of Ozone Depletion, where value is given as <<1.
(4) WMO et al. (2018). Scientific Assessment of Ozone Depletion.