| The energy efficiency improvement of existing residential buildings is a key factor affecting the overall building energy consumption.China's demonstration project for energy efficiency retrofit of existing residential buildings has now spanned three five-year plans,and the design standards for energy efficiency retrofit have increased from 50%to 75%.The specific retrofitting plan and strategy of the residential building retrofit project in the same climate region are similar.It is very important to evaluate the cost-effectiveness of various retrofitting schemes of different retrofitting projects.It is beneficial for the energy efficiency retrofit project to determine the priority of the retrofitting when faced with limited budget and resources,and find the weak point for improvement and large-scale popularization of retrofitting.Of course,the cost of energy efficiency retrofits and the expected benefits from retrofitting are affected by many factors.However,the improvement plan of the higher energy-saving standard has increased a lot because of the technical improvement cost,and the benefits generated by it can recover the cost in the life cycle of the retrofitting and achieve a certain return,which has not been studied and solved.This paper puts forward the analysis framework and evaluation index of the cost and benefit of energy efficiency retrofit in residential buildings,and according to the principle of case selection,three typical energy efficiency retrofit cases of Case ?,Case? and Case ? in cold area are selected,which are 50%,65%and 75%respectively,as the research object,Compare and analyze the technical scheme of several typical retrofitting cases and the cost composition of its life cycle.On the basis of the analysis framework,the comprehensive benefit measurement model of energy efficiency retrofit of residential buildings in cold areas is established,and the comprehensive benefits of many typical cases are measured.Finally,the cost-effectiveness of three typical retrofit cases is evaluated.The comparison results show that:1)The net present value of three retrofitting cases as a whole in its whole life cycle is greater than 0,and the retrofitting has a good return on investment.2)The retrofit of heating system and renewable energy application has good economy,considering the investment cost,priority is given to the retrofit of heating system.Although the initial investment of solar hot water system is high,the late income is very objective.3)The energy efficiency retrofitting of building envelope structure should actively explore innovative technologies to enhance the economical of the retrofitting of high energy-saving standard building envelope.4)The proportion of heat dissipation of external wall decreases and the proportion of external window increases before and after the retrofit of main parts of building envelope.External wall retrofit costs account for a large proportion,which is the key to cost control and technological upgrading.We should try our best to find the best balance point of energy efficiency retrofit economy of external wall and external window.5)When the comprehensive efficiency of heat source and heating system is low,improving the comprehensive efficiency will bring good comprehensive benefits and greatly improve the energy-saving effect of buildings.Rising energy prices have significantly improved the overall efficiency of the retrofit.With the improvement of energy-saving requirements,the impact of the change of initial investment cost on the project benefit is gradually increasing,which shows that controlling the initial investment cost is the key to energy efficiency retrofit.This article includes 22 figures,20 tables and 72 references... |
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