CO2 applications: Buses

Berliner Verkehrsbetriebe (BVG) has installed CO2 air-conditioning systems in seven of its city buses operating on different routes in Berlin and covering 200 to 400 km per day. Germany's Federal Environment Agency has urged all public transport suppliers to adopt CO2 cooling as a standard. If results from real-life tests are satisfactory, BVG is open to install R744 air conditioning in all city buses. BVG's decision to replace R134a with CO2 in its cooling systems was lauded by the German Federal Environment Agency (UBA) President Flasbarth as "farsightedness". Konvekta has supplied the innovative R744 systems and is conducting workshops on the handling of CO2 air-conditioning systems for bus manufacturers and operators, with a focus on the economic benefits and functional and maintenance features. In contrast to conventional air-conditioning units, the transcritical CO2 unit developed by Konvekta can be used for heating thanks to the reversal heat pump. While in 1993 only 5% of all new city buses in Germany were equipped with an air-conditioning system, this figure rose to 64% in 2008. 100% of all long-distance coaches today are equipped with air conditioning. With an average leakage rate of 13.3% for new coaches and 13.7% for new city buses, all German buses together emitted 100 tonnes of R134a in 2008 alone (140000 tonnes of CO2 equivalents).