Here, we estimate the carbon footprint of domestic cooling systems. Whether these are air-conditioners or heat pumps, their carbon footprint is mainly linked to refrigerant leaks (even if the cooling mode is rarely or never used).
The environmental footprint comprises four components:
- electricity consumption (this is already factored into the home’s electricity bill)
- the environmental footprint of manufacturing the equipment (negligible compared to refrigerant leaks; not taken into account here as we are not currently considering the environmental footprint of heating systems)
- the environmental footprint of annual refrigerant leaks
- the carbon footprint of refrigerant leaks at the end of the product’s life
The ADEME study ‘Modelling and environmental assessment of consumer products and capital goods’ provides a figure for ‘portable air conditioners’, but the assumptions appear to be outdated:
- the annual leakage rate considered is quite low (1%) and, in our view, should vary depending on how the air conditioner is used.
- The end-of-life leakage rate is not clearly specified
- The R134a refrigerant, considered in the study, does not appear to be representative of the current stock of air conditioners. R410a is more representative of older systems, whilst R32 is increasingly being used. Finally, this study does not mention heat pumps, yet we wish to adopt a similar modelling approach for heat pumps using a different set of assumptions.
