Energy efficient office buildings with passive cooling – Results and experiences from a research and demonstration programme in Germany

To gain access to the energy use in office buildings, the German Federal Ministry for Economy 1995 launched an intensive research and demonstration programme. In advance of the 2002 EU energy performance directive a limited primary energy coefficient of about 100 kWhm-2a-1 as a goal for the complete building services technology was postulated (HVAC + lighting). Further condition was that active cooling be avoided. Techniques like natural or mechanical night ventilation or heat removal by slap cooling with vertical ground pipes were applied as well as earth-to-air heat exchangers in the ventilation system. An accompanying research was established to keep track of the results and lessons learned from about 22 demonstration buildings realized and monitored until end of 2004. As one outcome this paper summarizes the energy performance of a selection of characteristic buildings together with an overview on the summer thermal comfort situations achieved.