Experience from various pilot and demonstration projects and the assessment of experts suggest that heating and cooling systems are often oversized. However, as there were no systematic studies on this topic in Switzerland, the Swiss Federal Office of Energy (SFOE) commissioned the SPF and the IET - Institute of Energy Technology with the OptiPower project. The team analysed a total of 341 heating systems in apartment buildings and ten administrative buildings with regard to the heating and cooling capacity actually required. It was found that in the apartment block sector, the systems are oversized by a median of 44 % and in the administrative buildings, the systems are oversized by a factor of 2-3.
