in the windows, wall, roof and floor of the four envelope components affect the energy consumption of the building, insulation performance of windows and doors is the worst, is one of the main factors affecting the quality of the indoor thermal environment and building energy saving. We present the typical envelope components, windows and doors consumption accounts for about 40%-50%. of total energy consumption of building envelope components according to statistics, in the heating or air conditioning in winter under the condition of single glass window heat loss accounted for about 30%-50% of heat load, the amount of solar radiation in summer due to cold heat through the single glass window into the interior and consumption of about for the air conditioning load 20%-30%. China building outside the window of the heat loss is Canada and other countries in the northern hemisphere similar buildings more than 2 times, reinforced doors and windows insulation doors and windows, reduce energy consumption, improve the quality of the indoor thermal environment and an important link to improve the level of building energy-saving.
The characteristics of residential building facade is more convex, complex shape coefficient. At present, residential building lighting and appearance in order to increase the lighting area or by using a large fan door Window, window wall area ratio increases, is not conducive to building energy saving. Energy saving standard residential buildings considering the building shape coefficient and window wall area ratio, according to the analysis and consideration of current energy saving technology mature degree of energy consumption in cold area and cold climate areas, determine the overall heat transfer coefficient of limit value.
In order to make the building to adapt to the climate conditions in different areas, to meet the requirements of energy-saving building envelope thermal performance requirements is more reasonable, the standard according to the number of heating degree days with air conditioning HDD18 degree days CCD26 as the climate division index, the subdivision in severe cold and cold regions for five different climate areas. According to the building of the building climate zoning, determine the thermal properties of building envelope structure reasonable, respectively put forward heat transfer coefficient of building envelope limit and windows Glass Shading coefficient of limit value.
In severe cold and cold regions, the heat loss of the heating period the temperature difference between indoor and outdoor heat transfer is dominant. Therefore, the window (including the transparent part of the balcony door) require high heat transfer coefficient. Influence of window on building energy consumption level mainly has two aspects, one is the window heat transfer coefficient influence winter heating and air conditioning in summer when the temperature difference between the indoor and outdoor heat transfer; another is the window affected by solar radiation caused by indoor heat. In winter, the solar radiation into the room through the window in favor of building energy saving, therefore, reducing the temperature difference of heat transfer coefficient of heat transfer window suppression is one of the main ways to reduce the heat loss of the window; while in summer, the solar radiation heat into the room through the window into the air conditioning cooling load, the temperature difference of heat transfer, reduce the solar radiation into the interior of the reduction and the window or the transparent curtain wall are ways to reduce the energy consumption of air conditioning.