Simulation Study On Low Energy Retrofit For Envelope Of Residential Building In Cold Area

The number of the existing buildings in China is huge and the energy consumption is high,so it is urgent to carry out energy-saving retrofit.The 13 th five-year plan for building energy conservation and green building development issued by the Ministry of Housing and Urban-Rural Development proposed the specific goal that during the 13 th five-year plan period more than 500 million square meters of existing residential buildings in severe cold and cold areas should be energy-saving retrofited.By doing so,not only can comfort levels of residents be greatly improved,but saving energy and reducing emission can be successfully realized,which is of great social significance for China to take the road of sustainable development.In this article,the energy-saving retrofit of the envelope of typical existing residential building in Beijing was studied.The retrofit schemes that meets the existing energy-saving standards,low energy saving standards and ultra-low energy saving standards are designed and compared.The DeST software was used to simulate the index of heat loss of envelope retrofit schemes that were designed by orthogonal test.The economic analysis of these schemes for the envelope was carried out.Firstly,three typical residential buildings with different layers are used as models.The retrofit schemes of the different envelope parameters of residential buildings were simulated using DeST software and the sensitivity coefficients of the parameters that influence the heat loss index of buildings were compared for the purpose of investigating the best retrofit scheme that maximizes energy saving rate,which provided a theoretical basis for the study of the low-energy retrofit of the building envelope.Secondly,the three building models were simulated with the existing energy-saving standards,low energy saving standards and ultra-low energy saving standards.By comparing the energy saving rate and economic indexs,the feasibility of envelope retrofit with the low energy saving standards is explained from the economic point of view.The environmental benefits of the retrofit schemes that meets the existing energy-saving standards,low energy saving standards are compared,and the important social significance of energy-saving retrofit of the envelope is pointed out.Finally,standard for the design of retrofit schemes of the envelope is to meet the limits of low energy standards,five levels of these components were chosen to design orthogonal test from external wall,roof and external window for envelope of the three building models.Factors order that influences index of heat loss have been concluded by orthogonal experiment range analytic method according to the calculation results of index of heat loss and economic indexes.The retrofit scheme that has the maximum net present value was taken as the economic optimal scheme for the retrofit of the envelope.