Marc Werro

Experience from various pilot and demonstration projects, as well as the assessment of experts, suggests that heating and cooling systems are often oversized. However, since 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 examined a total of 341 heating systems in the multi-family house sector and ten administrative buildings with regard to the heating and cooling power actually required based on the evaluation of measurement data and the installed power. It was found that in the multi-family housing sector there is a median oversizing of 44 % and in the administrative buildings the systems are oversized by a factor of 2-3. The project team further investigated how this oversizing affects the costs and efficiency of the heat pumps and formulated corresponding recommendations in the final report.