"Low-E glass"

Low-E glass

Low-E glass is also a type of coated glass. It is also called Low Emissivity. It is a thin film system made of a metal such as silver, copper or tin or a compound thereof. The coating layer has high transmission of visible light and high reflection of mid-range infrared rays, and has excellent heat insulation effect and good light transmittance compared with ordinary glass and conventional architectural coated glass. The basic colors of Low-E are three basic colors: blue, green and gray. Different processes can be made according to the reflection of different elements. For example, silver ash, light gray, light blue, gold, silver, and colorless and transparent, etc., can also be used to make other colors such as green with colored glass. How Low-E Glass works:

Since heat always flows from the high temperature end to the low temperature end, the heat in winter tends to flow from the indoor to the outside, and in summer it is the opposite. The film of the online low-emission (LOW-E) coated glass is effective in blocking heat loss. In the winter, sunlight can enter the room through the glass, and the heat gained from the sun, heating, etc. can be stored to prevent heat from being lost to the outside, making the interior warmer and more comfortable. In summer, the outdoor heat is blocked from entering the room, which makes the indoor air-conditioning refrigeration performance higher and lowers the cost of living.

Low-E glass features

1. Excellent thermal performance: The heat loss of the outer door and window glass is the main part of the building energy consumption, accounting for more than 50% of the building energy consumption. Relevant research data show that the heat transfer on the inner surface of the glass is mainly radiation, accounting for 58%, which means that the heat loss can be reduced by changing the performance of the glass. The most effective method is to suppress the radiation on the inner surface. Ordinary float glass has an emissivity of up to 0.84. When a low-emissivity film based on silver is applied, the emissivity can be reduced to less than 0.17, which is equivalent to a four-fold increase in the heat resistance of the glass. Therefore, the use of Low-E glass to manufacture building doors and windows can greatly reduce the transmission of indoor thermal energy to the outside due to radiation, effectively reducing the heating and cooling energy consumption of the building, and achieving the desired energy saving effect. 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 consumed by heating can be greatly reduced due to the reduction in heat loss, thereby reducing harmful gas emissions. The heat passing through the glass is two-way, and the heat can be transferred from the indoor to the outside, and vice versa, and simultaneously, but the problem of transmitting heat is poor. In the winter, the indoor temperature is higher than the outdoor, and insulation is required. In summer, the indoor temperature is lower than that of the outdoor, and the glass is required to be insulated, that is, the outdoor heat is transmitted to the room as little as possible. Low-E glass can meet the requirements of winter and summer. It can not only keep warm but also heat insulation, and it has the effect of environmental protection and low carbon.

2, good optical performance: Low-E glass has a high transmittance to visible light in sunlight, up to 80%, and the reflectance is very low, which makes the optical performance greatly improved compared with coated glass. From the outside, the appearance is more transparent and clear, which not only ensures the good lighting of the building, but also avoids the light pollution caused by the light reflection of the large-area glass curtain wall and the insulating glass door and window. At present, China requires the visible light reflectivity of the curtain wall to be no more than 30%. . Low-E classification:

Online Low-E and Offline Low-E can be divided into online Low-E and offline Low-E according to the Low-E production process: 1. Online high-temperature pyrolysis deposition method (online Low) -E) On-line high temperature pyrolysis deposition "Low-E" glass is completed during the float glass cooling process. The liquid metal or metal powder is sprayed directly onto the surface of the hot glass, and as the glass cools, the metal film becomes part of the glass. Therefore, the film is hard and durable (also known as hard film), and the film layer can be kept for 30 years without problems.

The "Low-E" glass produced by this method has many advantages: because it is a "hard film", it has the characteristics of wear resistance and rub resistance, and can be bent, tempered, laminated, silk screen, etc., can be used in a single piece, and is not required when hollow. In addition to the edge film, the film layer is firm, chemical stability is good, with high temperature resistance, corrosion resistance, oxidation, long life and so on, can be stored for a long time. Its disadvantage is that the thermal performance is relatively poor, and the "u" value is only half that of the "Low-E" coated glass by sputtering.

Note: The "u" value is the heat transfer amount, and the lower the heat transfer amount, the better the heat insulation performance. The "u" value is directly related to the radiance of the glass. Generally, the radiance of the float glass is 0.84. Most of the online thermal polymerization "Low-E" coated glass has an emissivity between 0.35 and 0.5. The illuminance of magnetron-vacuum-sprayed "Low-E" coated glass is between 0.08 and 0.17. It is worth noting that the low emissivity directly corresponds to a low "u" value. The closer the radiance of the glass is to zero, the better the thermal insulation performance. 2. Off-line vacuum sputtering (offline Low-E) off-line production of Low-E glass is currently widely used in the world for off-line vacuum magnetron sputtering coating technology. That is, in the vacuum chamber, the surface of the metal target is bombarded with high-energy particles, the atom is obtained with sufficient energy to be splashed into the gas phase, and then deposited on the surface of the glass. The film layer belongs to “soft coating”, and the film layer has poor firmness. Almost bare to save. The sputtering process produces "Low-E" glass, which requires a layer of pure silver film as the functional film and a pure silver film between the two metal oxide films. The metal oxide film provides protection to the pure silver film and increases the color purity and light transmittance as an intermediate layer between the film layers.

Advantages: Due to a variety of metal target selection and a variety of metal target combinations, the "Low-E" glass produced by sputtering can be used in a variety of configurations. It is superior to thermal spraying in terms of color and purity, because it is offline. It is also more flexible in terms of new product development. The main advantage is that the "Low-E" insulating glass produced by sputtering has a "u" value which is superior to the "u" value of the pyrolysis product.

Disadvantages: The silver oxide film layer is very fragile, easily scratched and oxidized, and cannot be used like ordinary glass. It must be processed into hollow glass in a short period of time, and the edge coating must be removed when forming the insulating glass, and it is not suitable for long-distance transportation and storage before it is made into a hollow product. Due to the weak respiration of the insulating glass, water vapor, sulfide and oxide enter the cavity, which leads to the gradual loss of the thermal insulation properties of the offline Low-E glass, the appearance of the black, discolored, and gradually a large number of mildew. The high-transmission Low-E and the shade-type Low-E can be divided into the following two types according to the difference in Low-E light transmittance: 1. High-permeability Low-E glass: High-permeability Low-E glass has High visible light transmittance, high solar energy transmittance and far-infrared emissivity, so the lighting is excellent, the solar heat radiation through the glass is much, and the heat insulation performance is excellent, which is suitable for the cold regions in the north and parts of the region. A transparent building that highlights natural lighting.

2. Sun-type Low-E glass: The shade-type Low-E glass has a certain shading effect on the indoor line of sight, which can prevent the solar heat radiation from entering the room, and restricts the secondary heat radiation outside the summer to enter the room, and is suitable for both the south and the north. Suitable for all types of buildings due to its rich decorative effect and outdoor line of sight shading. Single silver Low-E and double silver Low-E can be divided into the following two types according to the Low-E silver-containing film layer: 1. Single silver Low-E glass: single silver Low-E coated glass is usually only Contains a functional layer (silver layer), plus other metal and compound layers, the total number of layers reaches 5 layers.

2. Double-silver Low-E glass: Double-silver Low-E coated glass has two functional layers (silver layer), plus other metal and compound layers, the total number of layers reaches 9 layers. However, the technical process control of the double-silver Low-E glass is much more difficult than the single silver.

Comparison of single silver Low-E glass and double silver Low-E glass: 1. Double silver Low-E glass has lower emissivity and lower heat transfer coefficient than single silver LOW-E under the same glass combination. (U value).

2. Double silver Low-E glass has a lower shading coefficient, ie, Sc value.

3. In the case where the shading coefficient (Sc value) is the same, the visible light transmittance is higher than that of the single silver Low-E. In short, the double-silver Low-E glass highlights the shielding effect of glass on solar heat radiation, and combines the high light transmittance of glass with the low permeability of solar heat radiation to successfully solve the high light transmission. The problem of coexistence with the low U and Sc values has a better energy saving effect, which is an advantage that no other glass can have. Common Low-E glass

Our company always has 6mm, 8mm online Jinjing Pubai high permeability Low-E and AGC talk about gray SYA (Sunergy? A) Low-E, the layout is 2440×3300, the optical parameters are as follows: