2024 - The Second SUN; UV Automatic Control System

The Second Sun; UV Automatic Control System

The Second SUN is a new lighting panel system designed to automatically control UV exposure from day to day and create healthier living conditions in modern high-rise buildings with predominantly glass facades.

These days, many high-rise buildings take the form of curtain wall windows, through which natural lighting has the advantage of reducing energy by lighting the interior richly and uniformly, but excessive natural lighting can be poisonous.
Excessive UV exposure through windows increases the internal temperature, reduces heating and cooling efficiency, causes discoloration in objects and furniture near windows, and negatively affects the skin of building users.

Solar UV rays are classified into ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC) depending on the length of the wavelength.

Because UVA has a long wavelength among UV rays, it can pass through windows, so it penetrates into the dermis indoors and has a negative impact on the skin. In addition to promoting wrinkles and aging of the skin, it can also cause skin cancer through DNA mutations and direct toxic effects.

UVB rays have a stronger energy than UVA rays, which can cause sunburn, skin cancer, photoaging, pigmentation, and cataracts when exposed for a long time. It also plays an important role in the conversion of probiotic D into vitamin D, which is essential for the human body, by activating it. UVB rays have a short wavelength and most of them do not pass through windows, so they can block UVB rays indoors. However, this also means that you will lose the opportunity to synthesize vitamin D.

If the windows are completely covered, the UV problem can be solved, but it takes away the advantages of the curtain wall window format. There are also ways to use films with UV protection, but there are several problems. The illumination is lowered by lowering the transparency of the windows to block heat or by increasing the color of the windows to absorb heat, which reduces heating efficiency and increases power consumption. In addition, most films usually have a short lifespan of about one to five years, and they are less durable and tend to be damaged during cleaning. These characteristics require periodic film replacement, but due to the nature of the curtain wall building, it is difficult to replace and the work is complicated.

The Second SUN proposes ways to save energy while preventing excessive UV light from entering while obtaining sufficient illumination along with aesthetic effects.

During the day, the sensor of the window detects the intensity of ultraviolet rays and opens and closes the mobile screen divided by the size of each window according to the intensity of the ultraviolet rays to block UVA.
The screen closes a little when the UV intensity is weak through the sensor, and closes more as the intensity increases. This ensures light and illumination while preventing excessive UV radiation
The screen uses magnesium oxide as its material. The material has a reflectance of 93 percent, which is very effective for UV protection as well as heat protection. In addition, even when the screen is completely closed, light leaks through the small rectangular holes on the screen, causing an aesthetic effect.

When the sun goes down and the UV rays come down below a certain level, all of the mobile screens are closed and the vitamin D LED panels are lit. These LED lights activate the user’s vitamin D synthesis. The vitamin D LED panels are designed in the form of indirect lighting in a square hole installed on the screen to minimize skin irritation because direct exposure to it for a long time can irritate the skin.

The UV automatic control system project, The Second Sun takes away the advantages and disadvantages of lighting curtain wall buildings. It will save energy, prevent excessive exposure of UVA, and help improve the health and quality of indoor living for modern people who are expected to lack vitamin D.