Establishment of leakage rates of mobile air conditioners in heavy duty vehicles. 2. Buses and coaches. Final report.

Author(s) : Eur. Comm., Öko-Rech., SCHWARZ W.

Type of monograph: Report


On behalf of the European Commission, this study establishes empirically the annual leakage rate of mobile air conditioners (MACs) in buses and coaches for the use-phase of the vehicles. In buses, refills are carried out in relatively short service intervals to compensate for leakages whatever their nature. Such refills are recorded over a sufficiently long time and in appropriate detail in Sweden where annual inspection is mandatory for every installation with a refrigerant charge of HFCs more than 3 kg. The refill-based approach of this study consists in the analysis of approximately 2,000 report forms on inspections of MACs of buses and coaches in a specialised garage in South-East Sweden over the 1996-2005 period. One of the most important results of this study is that it is possible to reduce the annual leakage rates of modern bus and coach MACs to approximately 1 kg, equivalent to 13% of the full refrigerant charge. These values enable the European Commission to make projections of bus specific emission levels of HFC-134a beyond 2010 if no additional policies and measures are undertaken. Extract from the table of contents: refill-based survey on use-phase leakage rate; selection criteria for a representative bus survey (main features of MACs of buses over 8 t GVW; 5 main technologies of bus MACs; high leakage risk due to long piping and numerous connections); composition of the analysed Swedish sample; the annual leakage of bus and coach air conditioners (overall leakage rates; leakage rates by design and fuel type, by bus manufacturers and by MAC makes; age dependency; reasons for lower MAC leakage rates of coaches compared to buses; similar rate of new coach and bus MACs). In the annex: estimation of excluded regular leakage; issues of measurement uncertainty in recorded refills; and contribution of individual components to the leakage rates. This final report can be downloaded from the Web site: See also this Bulletin, references 2008-1423 and 1425.


  • Original title: Establishment of leakage rates of mobile air conditioners in heavy duty vehicles. 2. Buses and coaches. Final report.
  • Record ID : 2008-1424
  • Languages: English
  • Subject: Figures, economy, Regulation, Technology, Environment, HFCs alternatives
  • Publication: European commission, dg environnement - Belgium/Belgium
  • Publication date: 2007/01/31
  • Source: Source: 61 p. (21 x 29.7); fig.; phot.; tabl.; ref.; 3 append.