Ultraviolet was discovered in the early 19th century and generally refers to light radiation with a wavelength of 100 nm to 380 nm. Ultraviolet radiation is a double-edged sword to human life. UV protect people but too much UV will be harmful.
Low-E glass is more and more widely used, but people are more concerned about the blocking effect of Low-E glass on infrared radiation, and seldom care about its block function of ultraviolet rays. This article introduces the effects and effects of ultraviolet rays on the human body and objects, discusses the attenuation of Low-E glass to ultraviolet rays, and gives suggestions.
solar energy -Ultraviolet
The function &influence of Ultraviolet
The influence on human body
Appropriate amount of ultraviolet rays are helpful to human body, it can promote the production of vitamin D. and promote the absorption of calcium.However,if the human body is exposed to excessive ultraviolet rays,a series of changes in the body, causing damage to the eyes, skin, immune system, etc.
UV effect on human body
The influence on bamboo and wood
The main components of bamboo and wood materials such as cellulose and hemicellulose absorb ultraviolet rays to a certain extent. After absorption, the molecular structure will be damaged, and its physical and chemical properties will also be seriously affected, which ultimately affects the stability,Performance, durability, aesthetics of bamboo and wood materials.
long time sunlight cause furniture fading
The influence on Polymer Materials
Polymer materials include plastics, rubber, fibers, films, adhesives and coatings, etc., which are widely used in indoor furniture and installations. When polymer materials are irradiated with light, the molecular chain of the material is broken, the physical and mechanical properties are deteriorated, and the chemical structure is changed, thereby partially losing or losing its use value, and appearing hard, sticky, brittle, discolored, and losing strength.
Resin roof color fading
The UV blocking effect of normal insulated glass
The GlassSpec2500 building glass spectrophotometer is used to measure the ultraviolet transmission of common glass. The measuring wavelength range of this instrument is 300nm～2500nm. It can directly measure the ultraviolet transmittance of insulated glass without destroying the glass structure.
GlassSpec2500 Spectrophotometer
Before the test we must be clear that UVC comes from manual lighting,other UV brands-UVA (wavelength 315-380nm) and UVB (wavelength 280-315nm) can penetrate the glass,Below is the test result:insulated glass (6+12A+6) made with clear glass can block 52.56% UV,clear glass can block 100% UVB (wavelength 280nm-315nm) and low iron insulated glass block 24.48% UV,but allows 28% UVB transmission.
| Glass type | Glass structure | UV transmittance % | UVA transmittance | UVB transmittance |
|---|---|---|---|---|
| Clear Insulated glass | 6+12A+6 | 47.44% | 48.78% | 0% |
| Low iron insulated glass | 6+12A+6 | 75.52% | 76.86% | 28.13% |
The UV blocking effect of low e insulated glass
Below table shows the UV transmission of single silver low-E,double silver low-E and triple silver low-E.
| Glass type | Glass structure | UV transmittance % | UVA transmittance | UVB transmittance |
|---|---|---|---|---|
| Single silver lowe | 6 low-e+12A+6 | 32.38% | 33.29% | 0% |
| Double silver lowe | 6 low-e+12A+6 | 15.11% | 15.53% | 0% |
| Triple silver lowe | 6 low-e+12A+6 | 8.43% | 8.67% | 0% |
Conclusion:
The ultraviolet rays blocking effected is sorted from strong to weak: triple silver low e IGU> double silver low E IGU> single silverLow e IGU> clear insulated glass > low iron insulated glass.Low-E insulating glass can block more ultraviolet rays and reduce the incidence of ultraviolet rays into the room.
UV transmittance of different insulated glass
In practical applications, we can change the transmittance of the Low-E film in various bands by changing the thickness of the Low-E coating to further affect the UV transmittance. The thicker the Low-E film, the stronger block effect.
Is it necessary to consider the UV blocking of Low-E glass ?
In the current scientific cognition, UVA has not yet found its direct benefit to the human body, that is, no matter how much Low-E glass attenuates ultraviolet rays, the human body cannot benefit from the ultraviolet radiation passing through the glass.
The short-wave part of UVB also has a sterilization effect,but only low iron glass allows UVB transmittance, clear glass blocked 100% UVB.
No matter how much the UV transmittance ,the UV transmitted through Low-E insulated glass don’t play the role of disinfection and sterilization.
Soaking up the sun in front of indoor glass windows is far less effective than outdoors.
outdoor sunlight
When indoor bamboo and wood materials and polymer materials (plastics, paints, etc.) are used frequently, attention should be paid to the attenuation of ultraviolet rays when choosing Low-E glass, and the ultraviolet rays entering the room should be minimized.
For museums and libraries, in order to reduce the impact of ultraviolet rays on cultural relics, books, calligraphy, etc., it is necessary to consider the attenuation of Low-E glass to ultraviolet rays,in this case,laminated insulated glass will be perfect which can not only block 100% UV but also offering good thermal insulation performance.
Library should avoid UV rays transmission
Morn is your turnkey insulated glass manufacturer and supplier in China,we offer high UV blocking insulated glass,especially triple silver low-E insulating glass with high performance,welcome contact us if you got any projects require UV block glass.
Download this article here:Ultraviolet block function of low-E coating
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