Research Of Green Energy-saving Building External Aluminum Window Systems

Windows are the weakest link of energy efficiency in building envelope component, so windows energy-saving is an important part of building energy efficiency. The thermal insulation and overall performance of window system is more excellent to achieve the requirement of building energy efficiency. Because having better energy saving effect, the window system is the important developing trend in the future. At present, the domestic window system is in the initial stage. The various subsystems of architectural window system have significant impact on the thermal performance of systematic window.In this paper, based on the analysis of the present situation of domestic and foreign research for the aluminum external window systems and thermal theoretical basis, the glass subsystem, profile subsystem and the whole window’s performance of the aluminum architectural external window systems have been adequately analyzed, providing the theoretical basis for the design of aluminum systematic window. The green energy-saving aluminum external window systems have been developed.The insulating glasses of different configuration are simulated by using the software of WINDOW7.4. The impacts of the spacer layer’s thickness and layers number, low emissivity coating layers and location, the type and ratio of filled gas and the vacuum layer on the thermal performance of insulating glasses are studied. The trend of thermal performance to impacts of the second gas spacer layer thickness on the insulating glass of three-glass and two-chamber is first decreased significantly and then slowly rising, same to the two insulating glass of two-glass and single-cavity. By using THERM7.4 to simulate the thermal transmittance of aluminum external windows node, the impacts of the width and shape of the insulation strip and sealing method on the thermal performance of the aluminum external window’s profile subsystem are studied.By focusing on the study to the shape of the insulation strip,it is found that the thermal transmittance of aluminum external windows node decreases as the increasing of the complex shape of the insulation strip’s shape. Considering the factor of cost, the shape of insulation strip should not be too complicated. According to the results of simulation and analysis, the glass configuration, profile structure, sealing method, type and structure of the aluminum architectural external window systems are determined. By using THERM7.4 and WINDOW7.4 software to simulate and analysis the thermal transmittance of the cross section node and the overall window for the different design, the final program is determined.The configuration of glass subsystem has huge impact on the the overall aluminum system external windows. The improvement of glass subsystem configuration is an important means to improve the overall window thermal performance of aluminum external window systems.