(Peer version December 11, 2025, i.e. please send feedback to info@transportmeasures.org)

An area seldom included in the analysis of climate impact from transportation is leakage of refrigerants from  thermo equipment that may have a huge potential climate impact. Originally the refrigerants were CFC in these equipment’s but due to severe impact on the ozone layer they were in accordance with the Montreal protocol replaced by HFC.

Various refrigerants and their calculated ozone and climate impact

Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) contains carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F). The most common example of a CFC is dichlorodifluoromethane (R-12), commonly called Freon, used as a refrigerant. Many CFCs have been used as a refrigerant but due to their contribution to ozone depletion they have been phased out according to the UN Montreal Protocol, and replaced by other refrigerants such as hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) including cooling media as R-410A, R-134a and R-1234yf with significantly lower ozone depletion potential (ODP) but much higher global warming potential (GWP).

Figure 1. Refrigerants ozone depletion potential  and global warming potential (IU, no information)

Source: Transportlogistik och Miljö 2018

In theory and in legislation thermo equipment’s are not supposed to leak refrigerants. In legislation they should undergo annual control and maintenance in order to fulfil the technical specifications of no leakage. Every service and replacement of refrigerants must be reported. This is unfortunately not carried out sufficiently. In general, the equipment only undergo an ocular inspection and receive approval for another year.

The leakage originates from various wear over the years in pipe connections, valves, compressors, condensers etc. When the equipment is delivered from the factory it can be considered to have no leakage. Estimating the amount for topping up all systems an estimation of annual leakage is 5 to 10 %. In trucks the amount is approximately 4.5 kg and in trailers the amount is approximately 6.5 kg

Calculation example based on GHG impact from thermos transport

In Sweden there are some 4000 equipment’s in trailers and 8000 equipment’s in vehicles. This would in total sum up to 62 000 kg of refrigerants. Assuming a leakage of 7.5 %, that is 4650 kg annually. The annual CO₂e emissions would be 22 320 tonnes. The total emissions of CO₂ from goods transport in Sweden is approximately 11 000 000 tonnes.

For a truck the economic life length could be assumed at 8 years. Leakage of 7.5 % would correspond to exchanging refrigerants every 13.3 years. For the 8 years period that would correspond to 60 % of the total leakage (8/13.3). Trailers would approximately have a life length of 10 years that would lead to 75 % (10/13.3).

Figure 2. Based on an analysis of additional energy use and related GHG emissions

Given the size of the leakage factors, we do not recommend to consider this aspect in separate transport evaluations. We do however believe this aspect must be cautiously taken  care of in the general preventive environmental and climate work in transport operation and management.