Deutsche Umwelthilfe launches campaign to promote the use of CO2 MAC for buses

By Simon Burkel, Jul 17, 2013, 10:16 3 minute reading

The German environmental group Deutsche Umwelthilfe has launched a new campaign to promote the use of CO2 in mobile air conditioning (MAC) for buses. Launched on 28 June 2013 in Berlin, the campaign for sustainable AC in buses encourages manufacturers to offer CO2 MAC as a standard so that transport providers will be able to equip their buses with this system.  

Air-conditioning in buses has a huge impact on climate

The use of air conditioning on buses is clearly rising. 70% of city buses and 84% of intercity buses in Germany use air-conditioning today. But even if buses are considered an environmentally friendly means of transport, their refrigeration systems are not so green. Since MACs for buses are not hermetically sealed systems, the refrigerant leaks out throughout the lifetime of a bus causing significant greenhouse gas emissions. The average refrigerant leakage rate is about 13 – 15 % per year, leading to total refrigerant emissions of about 100 tons in Germany in 2011. This adds up to about 140.000 tons CO2 eq per year, equaling the CO2 emitted by 90.000 small cars. An alternative to the majority of synthetic refrigerants used today is CO2. While the market introduction of CO2 refrigeration technology for passenger cars is still experiencing some barriers, the CO2 technology for buses is already on the market. 
Campaign for sustainable AC in buses launched in June 2013
The campaign complements the already existing DUH initiative that promotes the use of climate friendly MACs in cars. The new bus campaign was launched in June 2013 and will run for two years. The aim is to fill existing information gaps, promote the advantages of CO2 and facilitate the ordering process for CO2 MACs. According to DUH, the following measures are required to increase the use of CO2 MAC in buses:
  • All leading bus manufacturers should offer CO2 MAC systems to their customers. 
  • Transportation companies and municipalities have to take CO2 MAC into account when ordering new air-conditioned buses.
  • Public funding schemes, especially for hybrid and battery driven buses must require criteria for sustainable MAC and favor CO2 as refrigerant.
Through technical discussions, workshops and public relations, the project, which is supported by the “Deutsche Bundesstiftung Umwelt (DBU),”  seeks to communicate the ecological as well as the economical advantages of CO2 in MAC. Furthermore the DUH will launch a survey to identify barriers to be overcome among manufacturers and transportation companies.
Patrick Huth, project manager vehicle cooling at DUH  explains: “We are convinced that the natural refrigerant CO2 is the best alternative both in cars and buses. But many transportation companies are not acquainted with the advantages of CO2 in MAC systems yet.  For these companies, our campaign will provide background information and an exchange of experience with bus operators that already use the refrigerant CO2.”
CO2 in MAC for buses increases efficiency by up to 25%  

CO2 refrigeration technology is environmentally friendly and exceeds the efficiency of R134a by up to 25%. A comparison between common synthetic refrigerants, such as R134a and R1234yf, and the natural refrigerant CO2 demonstrates the superior ecological, chemical, economic and safety characteristics of CO2. The service and maintenance costs of vehicles with air conditioning units that use CO2 as a refrigerant are much simpler and only require around a third of the service costs required for a standard R134a system.
Eight German transportation companies have already realized the advantages of CO2 and have equipped 33 buses with MAC units that employ CO2 as a refrigerant. 


By Simon Burkel

Jul 17, 2013, 10:16

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