The so-called door and window K value refers to the heat insulation coefficient of doors and windows; the so-called heat insulation coefficient of doors and windows, which is more common, is the ability of doors and windows to block heat. The lower the K value, the stronger the heat insulation ability of doors and windows, the thermal insulation performance of doors and windows. The stronger. Regarding the K value of the door and window, there is also a formula on the tall: k = 1 / (1/ai + Rw + 1 / ae), where Rw is the thermal resistance of the door window glass itself, and ai and ae are the heat transfer coefficient of the inner and outer surfaces, respectively. . The thermal resistance of the door form is an important condition for the insulation of the door and window. It depends on the glass used in the door and window. The glass used in most doors and windows is similar, and it is divided into single layer and double layer. The double-layer glass is improved on the basis of single-layer glass, and its thermal resistance is improved but it is lacking in essence. Leap, and a new type of material hollow glass, although it is also based on double-layer glass, but due to the intervention of the sealing firmware and bonding frame, its thermal resistance has been greatly improved. Therefore, the insulation ability of the doors and windows is fundamentally guaranteed. The heat transfer coefficient of the inner and outer surfaces depends on the selection of the glass inside and outside the door and window. At present, the internal and external heat transfer coefficients of the regular glass in the domestic market are guaranteed. According to another door and window k-value formula: k = k glass * f + k box * (1-f) (where f is the area of ​​the glass door as a whole), we can easily understand, in addition to glass, the door and window frame The choice and the area ratio of glass to door and window frames are also crucial. Whether it is plastic steel or aluminum, its thermal insulation coefficient is much lower than that of glass. Therefore, traditional door windows are important means to reduce the K-value of doors and windows by reducing the area occupied by doors and windows. Recently, new aluminum wood doors and windows and multi-cavity have emerged. The aluminum alloy doors and windows of the frame are made of materials with much higher thermal resistance than glass as the main material of the door and window frame, breaking through the bottleneck of the door and window k value. (Follow the WeChat public account "Jiuzhengmen window network: jiuzhengmenchuang"; pay attention to courtesy, scan code to send millions of business opportunities! Jiuzhengmen window network exchange group]
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How much do you know the door and window K?