Theoretical Analysis And Application Of Energy Efficiency In Buildings

Energy efficiency in buildings is a world problem, but in China it is under developed and begins very late, so research on energy efficiency in buildings in China is a pressed problem. The main contents of this paper are as follows: Finite difference method, harmonic wave method and response coefficient method have been utilized to analyze the unsteady thermal characteristics of wall insulation, the energy saving effect of composite insulator wall has been calculated. Finite element method has also been utilized to analyze the unsteady thermal characteristics of heat bridges of interior and exterior wall insulation and their heat transfer losses in residential buildings. The intensity of solar radiation in south wall of buildings in winter and solar radiation through south windows has been calculated hourly, and the utilization of solar energy has been analyzed by compared with heat load in south rooms of residential buildings. The glass energy efficiency in summer for shading solar heat and in winter for penetrating solar heat both are calculated and the model of solar heat synthesis efficiency coefficient （SEC） is established, it will help to analyze optimization of shading coefficient of glass system choice in buildings. Heating and air-conditioning energy consumption of existing residential building before and after energy-saving reconstruction in Tianjin and its reconstruction investment have been calculated, and latent economic benefit of energy efficiency in building, which can be used as reconstruction investment, has been put forward. Based on the running data of air-conditioning equipment, variation features of air-conditioning energy consumption in summer and selection method of heating and air-conditioning capacity have been analyzed. Surplus heat reclamation system of water system of gas engine driven heat pump has been designed, and security and explosion proof measure of gas engine driven heat pump’s plant room has also been discussed. To accelerate the process of research and development of energy efficiency in buildings in China, this paper conducted a theoretical and practical research with the climate and present status quo in north China. The methods and conclusions may be useful to the problem.