Wideband and Extended Wideband Temperature Operation Field Tests in Telephone Central Offices

Field tests involving wideband and extended wideband temperature operation were conducted in several electronic central offices in South Central Bell and Pennsylvania Bell during 1980-1982. Wideband temperature operation is defined as no space heating or cooling between 65 and 80°F with fan operation only when heating or cooling is required, or for ventilation. Extended wideband operation allows a further relaxation of temperature between 60 and 85°F when the building is unoccupied. Results from one South Central Bell office were reported earlier at the INTELEC ´82 conference. This report presents results from the tests conducted in the Pennsylvania Bell offices. The purpose of the tests was to determine the savings in energy and operating cost that could be achieved by allowing higher temperatures in central offices, and if any significant increase in equipment problems could be attributed to the higher temperatures. Two IAESS¿* offices at Hatboro and Norristown, Pa., were fully instrumented. A statistical analysis of the data obtained during the tests indicated yearly savings in environmental control operating costs of about 30 percent for wideband and 40 percent for extended wideband, as compared to nominal 75°F conditions. These results compare very well with analytical predictions and the results from the Birmingham, Ala., test reported earlier. Analysis of maintenance records (trouble tickets) indicated that there was no apparent increase in maintenance problems during the tests despite higher than normal office temperatures.