Because there is a desiccant that can absorb water molecules inside the insulating glass, the gas is dry, and when the temperature drops, condensation will not occur inside the insulating glass. At the same time, the dew point on the external surface of the insulating glass will also rise. For example, when the outdoor wind speed is 5m/s, the indoor temperature is 20 ℃, and the relative humidity is 60%, the 5mm glass starts to dew when the outdoor temperature is 8 ℃, while the 16mm (5+6+5) insulating glass starts to dew when the outdoor temperature is - 2 ℃ under the same conditions, and the 27mm (5+6+5+6+5) three-layer insulating glass starts to dew when the outdoor temperature is - 11 ℃. There are three modes of energy transfer in insulating glass: radiation transfer, convection transfer and conduction transfer. Radiation transmission of insulating glass structure is the transmission of energy in the form of radiation through radiation, which includes visible light, infrared light and ultraviolet radiation, just like the transmission of solar light. Reasonable configuration of insulating glass and reasonable thickness of insulating glass interlayer can minimize the transmission of energy through radiation, thus reducing energy loss. Convective transfer Convective transfer is due to the temperature difference on both sides of the glass, which causes the air to drop on the cold side and rise on the hot side, resulting in air convection and energy loss. There are several reasons for this phenomenon: First, the poor sealing between the glass and the surrounding frame system results in the direct exchange of gas inside and outside the window frame to generate convection, resulting in energy loss; Second, the internal space structure of the insulating glass is designed unreasonably, resulting in the convection of the gas inside the insulating glass due to the effect of temperature difference, driving the exchange of energy, thus causing the loss of energy; Third, the temperature difference between the inside and outside of the windows that constitute the whole system is large, resulting in a large temperature difference between the inside and outside of the insulating glass. With the help of cold radiation and heat conduction, air first generates convection on both sides of the insulating glass, and then passes through the insulating glass as a whole, resulting in energy loss. Reasonable design of insulating glass can reduce the convection of gas, thus reducing the convection loss of energy. Conduction transmission is to drive energy to move through the movement of object molecules to achieve the purpose of transmission, just like cooking with an iron pot and welding with an electric soldering iron. The transmission of energy by insulating glass is completed through the glass and the air inside. As we know, the thermal conductivity of glass is 0.77W/mk. The thermal conductivity of air is 0.028 W/mk, which shows that the thermal conductivity of glass is 27 times that of air. The presence of active molecules such as water molecules in the air is the main factor affecting the energy transmission and convection transmission performance of insulating glass. Therefore, improving the sealing performance of insulating glass is an important factor to improve the thermal insulation performance of insulating glass.
① High performance insulating glass with large energy saving effect can achieve a shielding coefficient of 0.22-0.49 due to a special metal film, which reduces the load of indoor air conditioning (cooling). The heat transfer coefficient is 1.4-2.8W (m2. K), which is better than ordinary insulating glass. It also plays an important role in reducing indoor heating load. Therefore, the larger the window is opened, the more obvious the energy-saving effect will be. ② Improving the indoor environment High performance insulating glass can intercept the considerable energy from the sun to the room, thus preventing discomfort caused by radiant heat and reducing glare caused by sunset sunlight. Insulating glass ③ rich color and artistic high-performance insulating glass has a variety of colors, which can be selected according to needs to achieve better artistic effect. ④ High performance insulating glass is applicable to public facilities such as office buildings, exhibition rooms, libraries, and special buildings requiring constant temperature and humidity such as computer rooms, precision instrument workshops, and chemical plants. In addition, it can also be used to prevent sunscreen and glare at sunset. Precautions: The insulating glass is sealed with dry air in the middle, so the internal air pressure changes according to the changes of temperature and air pressure, but only a small deformation occurs on the glass surface. In addition, minor warpage may occur during manufacturing, and distortion may also occur during construction. Therefore, including such factors, sometimes there are corresponding changes in reflection, which should be paid attention to. The reflection varies with different colors. The reflectivity of gold, copper and silver metal coatings is very high in the middle and far infrared region, that is, when the wavelength range is greater than 4 μ m. If the metal coating is of typical thickness, the total reflectivity can reach 90% - 95%, and the high infrared reflectivity is equivalent to the low emissivity (Low-e), which will reduce the radiation conversion of the inner and outer glass plates of the insulating glass module. Correspondingly, compared with the standard insulating glass component with the air layer of 12mm, its thermal insulation value can range from 0.3W/(m2. K). In addition, if the air in the component is replaced by heavy gas, its insulation value is 1.4W/(m2. K). By thinning the thickness of the metal layer, the light transmittance can be increased to about 60% - 60%. This extremely thin coating has a very good protective effect, while still having a very high infrared reflectance value, in the range of 85% or 75%. The air layer is 12mm, filled with heavy gas, and the insulation value of the coating can reach 1.6-1.9W/(m2. K).