The three properties of doors and windows refer to air tightness, water tightness and wind pressure resistance. These three properties are required in door and window inspection, and the physical triality of doors and windows generally refers to these three properties. In 1986, China promulgated the standard of physical three-property testing of building exterior windows, which was updated with 2002. The new national standard was revised in the following aspects:
(1) increase the air permeability per unit area as the classification index value, and comprehensively grade the air permeability classification index value per unit seam length.
(2) increase the content of air permeability under negative pressure difference detection.
(3) make regulations on the application scope of water tightness fluctuation and pressurization.
(4) increase the content of engineering inspection related to wind pressure resistance.
1. Wind pressure resistance refers to the fact that the outer doors and windows are normally closed without damage (such as cracking, panel damage, local yield, bonding failure, etc.) and the hardware is loose under the action of wind pressure, the ability to enable dysfunction such as difficulty. The detection method is to detect the ability of the specimen to resist damage and dysfunction under the action of instantaneous wind pressure.
2. Air permeability, also known as air tightness, refers to the ability to prevent air penetration when the outer doors and windows are normally closed. The air tightness of external doors and windows has a great influence on heat loss. The better the air tightness, the less heat exchange and the smaller the influence on room temperature. The indexes to measure air tightness are the air permeability per unit seam length and the air permeability per unit area when the pressure difference inside and outside the window is 10Pa under the standard state.
3. Water tightness refers to the ability to prevent rainwater leakage under the simultaneous action of wind and rain when the outer doors and windows are normally closed. Generally, the standard used for testing the watertightness of exterior doors and windows is according to the classification and testing method of air tightness, watertightness and wind pressure resistance of exterior doors and windows of buildings. This standard specifies in detail the requirements for testing equipment, the method of performance testing and the grading index of watertightness. The detection equipment simulates the simulated state of external doors and windows in stormy weather, and uses pressure supply system, water supply system, pressure measurement and water flow system to measure the pressure difference between both sides of external doors and windows, then determine the pressure difference during severe leakage, and finally determine the water tightness coefficient and grade of outer doors and windows.
