Determination of the insulation thickness for the residential building envelope in severe cold areas

As for the large energy consumption of the residential buildings in heating seasons in winter, energy efficiency retrofit has been carried in China. The energy efficiency retrofit for the existing buildings in heating areas is a complex project related to the buildings, heating system and heat users. The key problem in the energy efficiency retrofit - the envelope insulation was analyzed in this paper. A typical residential building in severe cold area in China was selected. Building energy consumption in different conditions of envelope insulation was simulated with DeST-h software. The relation formula between the building heat consumption, dynamic investment recovery period of the building envelope retrofit were fitted with Maple software. The mathematical model of the heat consumption index and dynamic investment were established. And the insulation layer thickness to the minimum dynamic investment recovery period was determined.