Effect of heat displacement in energy efficient residential buildings

During the last years, the requirements of the German Buildings Energy Saving Ordinance "EnEV" became more strict for both new and refurbished buildings. The decreasing transmission losses to the outside lead to an increasing importance of heat displacements between different dwellings within the building. Within a field test project, financed by the Federal Ministery for Economic Affairs and Energy (BMWi), the heat transmissions between dwellings of two buildings were quantified. Three residential buildings with each 30 apartments, built in the fifties, were differently refurbished. A high-resolution monitoring allows a detailed analysis of the efficiency of the buildings and their HVAC system, and provides the basis for the simulation models. As the results from the simulation of the heat transmission in the buildings show, some apartments can partially or even completely compensate the transmission losses over the building envelope through the heat gains received from neighboring apartments. For other apartments, losses to the neighbors represent a consistent part of the total heat losses.