Mechanical ventilation of digital equipment in exchange with high heatload

The authors show how Copenhagen Telephone Company (KTAS) solves the problems of high heat load in rooms with digital equipment, using nothing but filtered air. Experience with four years of operation of these integrated ventilation systems is described and their economics are considered, with particular emphasis on the running costs. Fifty-two systems are in service with heat loads of up to 350 W/m2. In the near future, load will rise to 500 W/m2. Consideration is given to planned improvements that will achieve even greater heat loads for the rooms. The authors show, in schematic form, the set-up used by KTAS to predict heat loads, i.e. the size of exchanges versus the heat load in W/m2