A system comparison between water and air-borne cooling systems for telephone exchanges

The authors compare three cooling systems (two airborne and one waterborne) for telephone exchanges: (1) cooling through a false floor; (2) conventional air conditioning; and (2) cooling with natural convection coils, for instance using the Ericsson cooling system ERICOOL. The waterborne natural-convection system appears to be the most advantageous. The system has the following advantages: lowest power consumption; easiest achievement of cooling reserve in case of main failure; best working environment in the switching room; greatest development potential for future electronic packaging structures with increased power densities