Retrofit of Existing Residential Building: a Case Study

Abstract

There are about 42 billion square meters of existing buildings in China. The energy efficiency of existing buildings directly relates to the energy consumption of the building sector. The retrofit of existing residential building began in the 1990s in Heilongjiang. The Sino-Canada demonstration project and Sino-France demonstration project of retrofitting existing residential buildings were carried out in 1997 and 2004, respectively. The retrofit method and energy conservation potential of the envelope and heating system of northern existing buildings are analyzed in this paper, combining the experiences of retrofitting existing residential buildings in Heilongjiang. The software was compiled to aid the design of the envelope retrofit in Heilongjiang and to analyze the working situation in existing residential building heating systems. The imbalance of the indoor temperature and the quantity of heating loss from opening the window in different retrofit projects are presented. The emphasis on energy efficiency retrofit of the envelope of existing residential buildings should be placed on the wall in northern region. It is possible to reduce about 50 percent of energy consumption of buildings by insulating the wall. The external insulation is suitable for retrofitting existing buildings, and the moisture transfer should be considered at the same time. To insure actual reduction in energy consumption, the heating system should be retrofitted when the envelope is insulated.