Study On The Ratio Of Window To Wall Of Residential Buildings In Northwestern Region Of China

The building energy consumption accounts for about30％of the totalenergy-consumption of the society in China，in which the heating energy consumption isa major component of building energy consumption，approximately30-50％of the heatloss through windows and doors。Area ratio of window to wall of building is not only animportant factor to the heat transfer of the exterior window，but also the key factor tothe natural lighting of the building。The research of the scholars of the past about it areisolated。The determination of the area ratio of window to wall is affected by lots offactors，such as climatic condition，solar radiation，window type，energy-savingrequirement，natural lighting and so on.The research of this article is based on the combination of the two main respectswhich affect the determination of the area ratio of window to wall。Firstly，we determinethe size of the area ratio of window to wall is0.2which satisfies the natural lightingdesign specification by the results of the neutral lighting simulation about the northwestresidential buildings。Secondly，we build a numerical model for it and make0.2as thestarting point of the simulation。We simulate the model under the conditions of weatherheating and the presence or absence of curtains in order to get the relationship betweenthe area ratio of window to wall and the energy consumption in different climate andsolar resultant partition. The results are as follows：There is a equilibrium point between heat loss and heat gain under the condition ofwithout heating in ⅠandⅡ types of solar partition。The value of severe cold zone ⅠandⅡ，cold zone Ⅱ are0.4,0.69and0.56under the condition of without curtains。There isno equilibrium point between heat loss and heat gain under the condition of without curtains in severe cold zone Ⅲ and cold zone Ⅳ。There are equilibrium points when thewindow have curtains and the value are0.64and0.83in the two zones。Windows arealways the heat loss component weather they have curtains or not in hot summer andcold winter zone，and the size of window is the smaller the batter in this condition，butno less than0.2.Windows are always the heat loss component weather they have curtains or notunder the condition of heating in different resultant partitions。the size of window is thesmaller the batter in this condition，but no less than0.2.