Research On Comprehensive Performance Optimization Of Existing Public Building's External Windows In Severe Cold Area

As the weak part of the enclosure structure,the comprehensive performance improvement of the external window is an important content of building energy conservation.In order to know the current Status of the windows on existing public buildings in severe cold area and put forward the corresponding improvement strategy,field investigation and measurement are used to collect data of shape,opening mode,performance and other aspects of the window on existing public buildings in cold area.This paper also analysis the problem that appear on window's thermal performance,lighting performance and air tightness and its causes.On this basis,the method of computer numerical simulation are used to study the effect that material and structure made on heat transfer coefficient,visible light transmittance,shading coefficient and the sound insulation of external window.Then put forward several reconstruction schemes that be suitable for the Window in cold area.Finally,in order to choose the best scheme,the energy saving performance,sound insulation performance and economic performance are analyzed according t o different reconstruction schemes.In addition,in view of the structure of window and wall junction,the effect of cracks made on indoor environment and energy consumption is studied,and the improvement strategy is put forwardThe investigation results show that poor windows mostly appeared on the buildings that built in 90 s and before.The problems include glass aging,dust accumulation,false window,ponding between glass layers,deformation of sealant strip and so on.The simulation results show that using Low-E glass and white glass instead of colored glass,filled the nonmetallic cavity of window frame with polyurethane foam(window heat transfer coefficient decreased by 5%-11%),Using PVC instead of aluminum as a spacer(window and edge glass heat transfer coefficient are reduced by 10%),using casement window instead of sliding window can reduce the building energy consumption.Through the simulation analysis of the comprehensive performance of several reconstruction schemes,it is found that the double frame window structure has a huge advantage in the severe cold region.Especially after adding the white insulating glass window on the indoor side of the white single glass window,the sound insulation increased by 36.11 d B,the total energy consumption decreased by 16.1%,and the static investment recovery period was only 1.43 years,which is worth adopting...