“You have to apply sunscreen even indoors” Is it true? Ask the window makers
The window industry admitted that it is true that the window does not block 100% of UV rays, so it is necessary to apply sunscreen or wear sunglasses even indoors. Technically, if you want to increase the UV blocking rate, you can increase it as much as you want, but then it harms indoor lighting and increases the price and weight of windows excessively. Fortunately, the technology is developing enough to develop domestic products with world-class insulation performance without harming mining.
If you access YouTube, there are several videos showing that you should apply sunscreen, whether it is in an office building, at home or indoors. The fact is that the glass windows do not completely filter out the UV rays. Not only simple YouTubers uploaded such videos, but also dermatologists and university hospitals’ official YouTube channels uploaded videos with the same content.
Both ultraviolet rays and infrared rays are bad for the skin, but especially if exposed to a lot of ultraviolet rays for a long time, you can get burns, skin aging, or even skin cancer, so you need to be careful. Summarizing the content of the videos, ultraviolet rays are divided into UV A, B, and C according to their nature, and UV A has the weakest intensity, but it can penetrate any object deeply, so it penetrates the window and enters the room. Therefore, if you sit close to the window or drive for a long time, you need to apply sunscreen or wear sunglasses for eye health.
The window industry admits that the video is real. However, it is explained that technically, the UV blocking rate can be increased as much as possible, and the blocking performance is deliberately adjusted for △indoor lighting △price △weight. An official from the window industry explained, “Technically, the UV transmittance can be lowered as much as possible, but then the room becomes darker and the product becomes excessively expensive, so we have to choose between UV transmittance and other performance.”
The UV blocking performance of windows is closely related to ‘insulation performance’, which greatly influences the quality of windows. Sunlight consists of ultraviolet rays, infrared rays, and visible rays, and heat has both ultraviolet rays and infrared rays. The most important criterion for judging the quality of windows is how much they reduce the cooling load in the summer by blocking outside heat. Eventually, window products have evolved안전놀이터to block ultraviolet and infrared rays.
The problem is that a window that blocks 100% of ultraviolet and infrared rays is not a good window. If so, you can sell it by attaching a black coating film to the glass like tinting a car glass. Windows and doors must transmit a certain level of visible light in sunlight for indoor lighting. As ultraviolet and infrared rays are blocked, visible rays are also blocked to some extent. In the end, when choosing a window, you have to decide whether to block a lot of UV rays and use black glass or to use transparent glass that allows some UV rays to pass through. The window industry is developing ‘low-emissivity/ low-emissivity
glass’, in which silver is coated on the surface of the glass to block ultraviolet rays.low radiation)’. There are several layers of silver coating, but triple low-E glass coated with silver three times blocks more UV rays, but it is expensive and heavy. In the market, double-roy glass is overwhelmingly sold. An industry insider said, “Triple low-e glass makes the inside so dark that it is difficult to find applications.” “The products on the market are also released with a ‘symbolic meaning’ that greatly increases the UV protection rate.”
The older the building with the old windows, the more UV rays are transmitted. Low-E glass first began to be used in commercial buildings such as office buildings as the building law changed in the late 2000s. For residential buildings, high-end houses and apartments first used single low-E glass with one layer of silver coating, but in 2018, when KCC Glass lowered the unit price of double low-E glass for the first time in Korea and launched ‘ MVR177 ‘, it began to expand to general housing.
Double low-e glass is divided into tempered glass and non-tempered glass. KCC Glass was able to lower the unit price of glass by omitting the heat treatment process. Although it cannot be used in high-rise buildings, it is said that there is no problem in using it in general apartments because it maintains strength and insulation performance with technology.
As interest in eco-friendliness and building insulation grows, sales of low-e glass are also increasing. Single low-E glass Aegis, launched by KCC Glass in 2015, sold 12 times the area of Yeouido until last year. Product performance is also getting better and better. The single low-E glass MVR170, released in 2020 , has improved shielding performance by 35% and insulation performance by 13-14% compared to existing products. Double Roy glass MZT152
, released last year, has the lowest heat transmittance rate among solid products in the world. The effect of blocking ultraviolet rays and infrared rays is 2.5 times stronger than general single-roy glass. LX
The aluminum system window ‘LX Z: IN Eurosystem 9 E9-ALS200’, which Hausys also released last year, has a thick silver coating on the glass surface to block more than 90% of outdoor UV rays.