Study On Existing Office Building Envelop Energy Efficiency Retrofit

Energy conservation is an important part of a conservation-minded society. Energy consumption of building operation is about a third of the whole society’s commodity energy use, and is one of the biggest energy saving potential fields. Therefore, it should be deemed to be the main part of energy conservation. On the one hand, we need to continue to promote the energy saving of new buildings, and on the other hand we also need to dig the energy saving potential of existing buildings. This paper selects existing office building which was built during 1980 s to 2005 as the object of study, and carries on the analysis on the energy conservation renovation of building envelop. Aims at evaluating the energy saving rates and the economical efficiencies of the various building envelop energy-saving technologies, and then find out the technological adaptabilities in different climate regions of China. On this basis, the optimize combination of various technologies can be achieved and the simple display of different technologies can be avoided, then the integrative reconstruction plan for building envelop of existing office building in different climate regions can be found out.During the study, using e QUEST to simulate the whole year energy consumption of existing office buildings in different climate regions, conduct the quantitative analysis of different building envelop energy-saving reconstruction technologies’ energy-saving benefits, and the economic benefits of exterior insulation reconstruction and outside window reconstruction are analyzed emphatically. Then, the appropriate single reconstruction technologies of external wall and window in each climate region were obtained. The external wall optimum insulation thickness and external window for severe cold region A should be 100 mm and high-transmittance Low-e glass window. The external wall optimum insulation thickness and external window for severe cold region B should be 90 mm and high-transmittance Low-e glass window. The external wall optimum insulation thickness and external window for cold region should be 70 mm and high-transmittance Low-e glass window. The external wall optimum insulation thickness and external window for hot-summer and cold-winter region should be 30 mm and sun-shielding Low-e glass window. Both external wall reconstruction and external window reconstruction are not suitable for hot-summer and warm-winter region.According to each region, this paper designed orthogonal test plan and integrated with the best economical efficiency single technologies. After the energy-saving and economic analyses, the optimum integrative reconstruction plan for building envelop of existing office building in different climate regions were proposed. The result shows that from north to south, energy-saving rate can reach 26.6%~9.9%.