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| Low-Emissivity Glass |
Energy efficiency and decoration effect are the two key requirements of modern architecture for glass. Low-E coated glass (Low-E glass) is a kind of glass on which surface several layers of metals or metallic compounds are sputtered. It has high visible transmission and high reflectance to far-infrared within the range of 4.5μm～25μm.Therefore, Low-E glass can supply very good heat insulating performance and meet the requirement of energy saving by preventing overfull solar energy coming into room during summertime and reducing indoor heat loss during wintertime. Furthermore, available various colors can satisfy the decoration requirement of building.
By reasonable configuring Low-E glass into IGU, it has become the best choice of modern architecture because of its excellent performance on heat insulating, sound insulating, heat preservation and lighting.
Low-E coated glass produced by ZAG consists of High-transmittance Low-e Glass, Shading Function Low-E Glass, Double Low-E Glass and Allopatric processable Low-E Glass.
Specification
Size
Standard Full Size: 2440mm X 3660mm, 2400mm X 3300mm
Maximum Size: 2540mm X 4600mm
Minimum Size: 300mm X 800mm
Thickness: 3mm-19mm
Quality Standard
Accordance with GB/T 18915.2-2002 China Coated Glass Standard |
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| High-transmittance Low-E Glass |
| Feature |
Higher visible transmission: Good outdoor transparency and ideal indoor natural lighting .
Higher solar energy transmission: Shading Coefficient SC≥0.5, more solar heat radiation can go into building through glass, slightly less than ordinary float glass.
Very High far infrared reflectance: Lower heat transfer coefficient U value, excellent heat preservation effect.
There is only one sliver layer in the structure of this type of Low-E glass. Various colors are available, no light pollution is caused. |
| Application |
Best for severe cold climate as well as cold climate. In these areas, Low-E glass allows large quantity of solar radiation enter into room during winter daytime to heat up indoor, in the mean time, it can reflect the far-infrared energy coming from heater, electrical appliances and human beings back into the room, especially in the nighttime, so that heating energy consumption is reduced effectively.
Buildings with high transparency design requirement. |
| Recommendation |
| Not suitable for buildings which have shading requirement. And application in areas requiring low shading coefficient SC value is not recommended. |
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| Shading function Low-E Glass |
| Feature |
Moderate visible transmission with certain shelter function to outdoor sight
Less solar heat radiation into room, shading coefficient SC≤0.5
Very high far-infrared reflectance, lower heat-transfer coefficient U value, outdoor thermal radiation into the room is reduced.
Only one sliver layer the structure of in this type of Low-E glass |
| Application |
More scientific to be applied in hot summer-warm winter area
Application in severe cold climate is not recommended.
With various reflective colors, it's suitable for buildings requiring decorative effects.
Buildings requiring certain outdoor sight shading. |
| Recommendation |
| Coating applied on the second surface of IGU |
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| Double Silver Low-E Glass |
| Double Low-E Glass is named because it contains two sliver layers. Its more complex layer stack highlights the shading function to solar thermal radiation, therefore the glass can obtain lower solar thermal radiation transmission while keeping the high visible transmission. Compared with ordinary Low-E glass (High-transmittance Low-E glass, Shading function Low-E Glass, Allopatric processable Low-E Glass and Pyrolytic Low-E Glass), Double Low-E Glass shows its unique advantages. |
| Feature |
Higher visible transmission, it allows to make full use of natural lighting.
Very low solar transmission: Solar thermal radiation transmission is effectively prevented, especially near infrared radiation. Shading coefficient SC is much lower.
Outdoor thermal radiation into room in summertime is more effectively prevented by much lower U value. While, better heat insulation can be obtained in wintertime. |
| Application |
| Applicable to various climates. |
| Hint |
The silver layer is the essential of Low-e layer stack structure and contributes to low heat-transfer coefficient U value. The allpied region and architecture of ordinary
High-transmittance Low-E, Shading Function Low-E, Pyrolytice Low-E and Allopatric processable Low-E are limited because there is only one silver layer in the layer stack. While, with two silver layers, Double Low-E can be applied to various regions and architectures with different functions.
Due to the complex structure of Double Low-E, only the large scale glass coating line with the most advanced configuration which were imported after the year of 2000 have the industrial capacity of Double Low-E. Most of the coating lines early imported don't have Double Low-E capacity or can not produce Double Low-E in large scale. |
| Allopatric processable Low-E Glass |
With the research and development of layer stacks from foreign equipment suppliers, allopatric processable Low-E technology has provided to the most advanced coating lines imported in recent years or the upgraded coating lines. With the cooperations of foreign process experts, ZAG has been producing successfully allopatric processable Low-E glass. This Low-E stack has very good antioxidation and long life-san.
The other advantage of allopatric processable Low-E glass is that it can allow curved Low-E glass and flat Low-E glass to obtain the identical color, in turn, to supply the building uniform appearance color.. |
Pyrolytic Low－E & Off-line Low-E Performance Comparison
Off-line Low-E glass is made by sputtering one or two silver layers and other medium layers under magnet field controlled vacuum environment. Various transmissions and reflective colors can be achieved by adjusting the thickness of layers. Low-E coating allows high infrared reflection and selective visible transmission. Therefore, it has advantages of energy saving, rich and colorful tones and strong decoration effect.
Pyrolytic Low-E glass is produced by spraying metal liquid or metal powder directly to the hot glass surface during the process of float glass annealing.
The biggest advantage of pyrolytic Low-E is that it can be stored for a pretty long term and can be reprocessed, for example, tempering. No expensive coating equipment is needed and cost is low while output is high.
The color range and spectral selectivity of pyrolytic Low-E is very limited. The biggest disadvantage is that its U value would be higher than that of vacuum sputtered Low-E with the same visible transmission, therefore it can not supply sufficient energy saving performance. Furthermore, it can not be SC selective according to various climates. |
