We have developed in our company a new method for cooling telecom equipment using fresh air year-round (no chillers). This new method, called MISTRAL, has already and successfully been implemented at more than 120 of our telecommunications centers.

A reduction of 90 percent of the energy needed for cooling can be reached using this fresh-air-only cooling method. An overall reduction of 45,000,000 kWh per year is expected after its full implementation at present sites (overall ca. 700 sites). This method is also deployed by the rollout of the broadband access network.

Last year, we also successfully investigated the implementation of this cooling method at mobile network sites. Today, more than 30 of our base transceiver stations (BTSs) are already cooled with this cooling solution.

Further environmental advantage of fresh-air-only cooling (no chillers) is that global-warming–contributing refrigerants are eliminated.

In addition to energy cost savings, capital costs can be reduced by a factor 3 to 4 using this fresh-air-only cooling method.

More information on this new cooling method can be found in www.swisscom-comtec.ch/pdf/comtec062005302.pdf.