1 How low radiance of the glass, then it could be called low e glass.
In physics, the objects whose radiance is lower than 0.15, we called it as low emissivity objects, if so, the radiance for all the low e glass should be lower than 0.15. In reality, the radiance for all the off-line low e glass is lower than 0.15, the radiance for double silver low e coated glass and triple silver low e coated glass is only 0.03. But for on-line low e glass, the radiance is higher than 0.15, it is around 0.18～0.22, then it shouldn’t be low emissivity objects, and it is also called K glass. Even so, the radiance for on-line low e glass is much lower than normal float glass with radiance 0.84, and been classified as low e glass.
2 How much ultraviolet rays can be reduced by the low e glass?
The ultraviolet-proof function for low e glass is different from low e glass types, the ultraviolet transmission is between 9% to 35%, this shows that more than 60% ultraviolet can be attenuated by the low e glass, but couldn’t be completely isolated. So the low e glass couldn’t prevent the colour fading for furniture, but it could slow down the colour fading process.
3 What is the effect on the house plant by low e glass.
The visible light and part ultraviolet could pass through the low e glass, it couldn’t affect the photosynthesis of plant, then low e glass don’t have any adverse affect for most normal plant. But for the plant which growth relays on the ultraviolet, such as the flower plants with dark purple color, the low e glass will have great effect on its growth.
4 Which kind of building need the ultraviolet? And which needn’t?
If to limit the transmittance of ultraviolet, is closely related to the function of building. For example, the museum should limit the ultraviolet strictly, because the ultraviolet will the harm the cultural relic, calligraphy and painting and so on. But for hospital and botanical museum, it need ultraviolet, because the ultraviolet can help to disinfect and promote the growth of plant. So when choose low e glass for different buildings, need to focus on the ultraviolet transmittance of low e glazing.
Post time: Aug-18-2022