Influence Of External Window Parameters On Building Load And Economic Analysis

China is a high energy consumption country. Window system is an essencial part ofthe building envelope which obtains30%of the total building energy consumption everyyear. So the window energy saving is very significant.This hypothesis selects a government office building in Wuhan for analyzing. Theconfiguration of physical parameters for that benchmark building bases on relevantstandards and the energy consumption is simulated by DeST which provide foundation forregulation of air conditioning/heating load and energy saving in next investigation.Air tightness level, heat transfer coefficient and shading coefficient of windows arethree major factors which influence on building load. Windows with same heat transfercoefficient, shading coefficient and different air tightness levels are chose to simulate thebuilding energy consumption when disscusing the influence of window air tightness level.Similarily, the window heat transfer coefficient should be variably as air tightness leveland shading coefficient keep constant that are suggested to be researching objection whilediscussing the effect of former one. To invesgate the influence of shading coefficient, thewindows which have same heat transfer coefficient and air tightness level with differentshading coefficient are used for simulation. This article seleced eight kinds of windowretrofitting schemes to sdudy, then simulated the energy comsumpion and made financialanalysis for each scheme. By camparation with energy saving amount and investmentpayback period, the optimal window energy saving scheme had been screened out.The research demonstrates, the air tightness level increases one level，the buildingload will decrease2%； the heat transfer coefficient decreases0.5W/(m2·K), the buildingload will decrease1.5%. And when the shading coefficient declined0.1, the heating loadwill increase2%while the cooling load will decrease1.5%. Among those schemes,whenconsiderating the cost, window used PVC plastic casement and Low-E hollow filled withinert gases is the optimal scheme As the consideration of the glass membrane and thecost,The investment payback period of thermal insulation membrane is shorter.