Low-E glass, also known as low-emissivity glass, is a film-based product composed of multiple layers of metal or other compounds plated on the glass surface. The coating layer has the characteristics of high transmission of visible light and high reflection of mid- and far-infrared rays, which makes it have excellent heat insulation effect and good light transmittance compared with ordinary glass and traditional architectural coated glass.
Glass is an important building material. With the continuous improvement of the decorative requirements of buildings, the use of glass in the construction industry is also increasing. Today, however, when people choose glass windows and doors for buildings, in addition to their aesthetic and appearance characteristics, they pay more attention to issues such as heat control, cooling costs and the comfort balance of interior sunlight projection. This makes the upstart Low-E glass in the coated glass family stand out and become the focus of attention.
Excellent thermal properties
The heat loss of exterior door and window glass is the main part of building energy consumption, accounting for more than 50% of building energy consumption. Relevant research data shows that the heat transfer on the inner surface of the glass is mainly radiation, accounting for 58%, which means that the most effective way to reduce the loss of heat energy is to change the performance of the glass. The emissivity of ordinary float glass is as high as 0.84. When a layer of silver-based low-emissivity film is coated, the emissivity can be reduced to below 0.15. Therefore, the use of Low-E glass to manufacture building doors and windows can greatly reduce the transfer of indoor heat energy caused by radiation to the outdoors, and achieve ideal energy-saving effects.
Another significant benefit of reduced indoor heat loss is environmental protection. In the cold season, the emission of harmful gases such as CO2 and SO2 caused by building heating is an important source of pollution. If Low-E glass is used, the fuel consumption for heating can be greatly reduced due to the reduction of heat loss, thereby reducing the emission of harmful gases.
The heat passing through the glass is bidirectional, that is, the heat can be transferred from the indoor to the outdoor, and vice versa, and it is carried out at the same time, only the problem of poor heat transfer. In winter, the indoor temperature is higher than the outdoor, so insulation is required. In summer, the indoor temperature is lower than the outdoor temperature, and the glass is required to be insulated, that is, the outdoor heat is transferred to the indoor as little as possible. Low-E glass can meet the requirements of winter and summer, both heat preservation and heat insulation, and has the effect of environmental protection and low carbon.
Good optical properties
The visible light transmittance of Low-E glass ranges from 0% to 95% in theory (6mm white glass is difficult to achieve), and the visible light transmittance represents the indoor lighting. The outdoor reflectivity is about 10%-30%. The outdoor reflectivity is the visible light reflectivity, which represents the reflective intensity or dazzling degree. At present, China requires the visible light reflectivity of the curtain wall to be no more than 30%.
The above characteristics of Low-E glass have made it increasingly widely used in developed countries. my country is a relatively energy-deficient country. The per capita energy consumption is very low, and building energy consumption accounts for about 27.5% of the country's total energy consumption. Therefore, vigorously developing the production technology of Low-E glass and promoting its application field will surely bring significant social and economic benefits. In the production of Low-E glass, due to the particularity of the material, it has higher requirements for cleaning brushes when it passes through the cleaning machine. The brush wire must be high-grade nylon brush wire such as PA1010, PA612, etc. The diameter of the wire is preferably 0.1-0.15mm. Because the brush wire has good softness, strong elasticity, acid and alkali resistance, and temperature resistance, it can easily remove the dust on the glass surface without causing scratches on the surface.
Low-E coated insulating glass is a better energy-saving lighting material. It has high solar transmission, very low "u" value, and, due to the effect of the coating, the heat reflected by the Low-E glass is returned to the room, making the temperature near the window glass higher, and people are not safe near the window glass. will feel too uncomfortable. The building with Low-E window glass has a relatively high indoor temperature, so it can maintain a relatively high indoor temperature in winter without frost, so that people indoors will feel more comfortable. Low-E glass can block a small amount of UV transmission, which is slightly helpful in preventing fading of indoor items.