Do not know the glass of doors and windows, especially low-e glass, today we have compiled 30 common low-e glass problems, and quickly collect it! Wenzhou fire glass customization
1. What kinds of composite products are there in glass?
There are mainly tempered, semi-tempered, sandwich, hollow, coated, and different combinations thereof. For example, tempered coated hollow glass, coated interlayer insulating glass, and the like.
2. What is the shading coefficient Sc, which part reflects the heat transfer?
Shading coefficient Sc: The ratio of the solar radiation energy transmitted through the glass to the solar radiation energy transmitted through the 3 mm transparent glass under the same conditions. The solar radiation energy through 3mm transparent glass is 630w/m2.
Shading coefficient Sc = direct solar radiation ÷ 630 w/m2
The direct solar radiation energy = 630 w / m 2 × Sc sunshade coefficient reflects the direct heat radiation of the sun through the glass.
3. Is the shading coefficient Sc high, or low?
Glass with different shading coefficients is suitable for areas with different climates. The sunshade coefficient is high, and the solar radiation entering the room through the glass window is much, thereby reducing the heating cost in winter. This glass is suitable for use in the long northern regions of winter. The shading coefficient is low, and the direct radiation to the sun is well blocked, which can reduce the direct solar radiation energy entering the room. This glass is suitable for use in the long southern regions of summer.
4. What is the U value? Which part of the heat transfer does it reflect?
The U value reflects the thermal energy transmitted through the glass due to convective conduction, including the transmission of the glass to absorb heat and then radiate outward. Therefore, the radiance E of the glass is low, and the U value is correspondingly low. Convective conduction heat energy = U value × (T outdoor - T indoor) T outdoor and T indoor are indoor and outdoor temperatures, respectively.
5. What are the components of the total heat transfer through the glass? How to express? Wenzhou fire glass customization
It consists of two parts: direct solar radiation heat transfer and convective conduction heat transfer. Formulated as: Q total = 630 × Sc + U × (T outdoor - T indoor) Wenzhou fire glass custom
6. What are the components of solar radiation?
It consists of three parts: ultraviolet radiation with a wavelength range of 0.01 to 0.38 microns. The visible wavelength range is 0.38 to 0.75 microns. Near infrared radiation, the wavelength range is 0.75 ~ 3 microns.
7. Does the far infrared heat radiation come directly from the sun?
Far-infrared heat radiation is indirectly from the sun. This part of the energy is heat energy, which is radiated by the sun after being absorbed by the object, and its wavelength range is 3 to 40 microns. In the summer, the far-infrared heat radiation emitted by outdoor roads and buildings under sunlight is one of the main heat sources from the outdoors.
8. Is there far infrared heat radiation in the room? Wenzhou tempered glass manufacturer
Yes, indoor far-infrared heat radiation comes from heating, household appliances, furniture that is exposed to sunlight, stoves and the human body. It is the main source of heat from indoors in winter.
9. How does far infrared heat radiation pass through the glass?
Far-infrared heat radiation cannot be transmitted directly through ordinary glass and can only be absorbed or reflected by glass. After the glass absorbs this part of the energy, the temperature will rise, and the part of the energy will be dissipated by conducting convection with the air and radiating heat radiation to both sides. Therefore, this part of the energy is transmitted through the glass, but only absorbed and re-radiated. Way through.
10. How to distinguish between far infrared heat radiation and near infrared radiation?
The near-infrared radiation comes directly from the sun, and its thermal sensation is not obvious, but it can be converted into heat after being absorbed by the object. Far-infrared heat radiation, as a result of solar energy conversion or the result of artificial production, is itself heat. Observing the road under the sun in summer, you can see that the heat radiation wave rises from the ground (that is, the solar energy is being converted into heat radiation). In the winter, close to the heating, you can directly feel the heat radiation.
11. What is Low-E glass?
Low-E glass is a low-emissivity glass that is coated on the surface of the glass to reduce the emissivity E of the glass from 0.84 to less than 0.15.
12. What are the characteristics of Low-E glass? Wenzhou fire glass customization
Low-E glass has the following characteristics: ★ High infrared reflectivity, which can directly reflect far-infrared heat radiation. ★ The surface emissivity E is low, and the ability to absorb external energy is small, so that less heat is radiated. ★The sunshade coefficient Sc is wide, and the amount of solar energy can be controlled as needed to meet the needs of different regions.
13. Why does the Low-E film reflect heat?
The Low-E film is plated with a silver layer that reflects more than 98% of the far-infrared heat radiation, reflecting the heat directly as reflected by the mirror. The low-E shading coefficient Sc can be from 0.2 to 0.7, so that the direct solar radiant energy entering the room can be regulated as needed.
14. What is heat reflective glass?
The heat-reflecting glass is a so-called coated glass which is formed by coating a glass surface to reduce the sunshade coefficient Sc of the glass from 0.98 (6 mm transparent glass) to 0.2 to 0.6.
15. What is the difference in function between Low-E glass and heat reflective glass?
The heat-reflecting glass reduces the air-conditioning cost and saves energy by reducing the sunshade coefficient of the glass and restricting the direct solar radiation from entering the room through the glass. Low-E glass reduces the convective heat transfer through the glass by reducing the U value of the glass and limiting the far-infrared heat radiation through the glass. At the same time, the sunshade coefficient Sc of the Low-E glass has a large adjustment range, and can effectively control the direct solar radiation entering the room.
16. What are the main types of mature coated glass processes?
There are two main types: on-line coating, vacuum magnetron sputtering (also known as off-line coating). The in-line coated glass is manufactured on a float glass production line, which has a single variety, poor heat reflection performance, and low manufacturing cost. The advantage is that it can be hot bent. Door and window empire, free resources platform for doors and windows industry. The coated glass produced by the vacuum magnetron sputtering process has various varieties, excellent heat reflection performance and obvious energy-saving characteristics. The disadvantage is that it cannot be bent. Wenzhou fire glass customization
17. Can Low-E glass be used in a single piece?
The Low-E glass manufactured by the vacuum magnetron sputtering process cannot be used in a single piece, and can only be used for synthesizing hollow glass or laminated glass. However, its emissivity E is much lower than 0.15 and can be as low as 0.1 or less. The Low-E glass produced by the in-line coating process can be used in a single piece, but its emissivity is E=0.28. Strictly speaking, it cannot be called Low-E glass. Scientifically, an object with an emissivity of E£0.15 is called low-emission. object). Low-E glass is effective in a similar enclosed space formed in a sealed insulating glass because this enclosed space eliminates the flow of air on the Low-E surface, thereby making the Low-E glass work better.
18. Is the performance of Low-E glass the same?
From a technical point of view, all Low-E glass processes the spectral curve in the same way, but the performance is not the same.
19. Does all Low-E glass look the same?
Different! Some Low-Es appear to have high transparency, a transmittance of over 60%, and a light color. Some Low-Es appear to have low transparency, a transmittance of less than 55%, and a relatively darker color.
20. Does Low-E glass still work at night?
Yes! Low-E glass works day and night. In the winter, heat (far infrared heat radiation) is reflected back into the room during the day and night, because the heat generated by the heating or the solar energy is in the form of far infrared heat radiation.
21. How does Low-E glass work in summer and winter?
In winter, the indoor temperature is higher than the outdoor, the far-infrared heat radiation mainly comes from the indoor, and the Low-E glass can reflect it back into the room to keep the heat in the room from diarrhea. For some solar radiation from the outside, Low-E glass still allows it to enter the chamber, which is absorbed by the indoor object and then converted into far infrared heat radiation to be left indoors. In summer, the outdoor temperature is higher than indoors, and the far-infrared heat radiation mainly comes from the outside. Low-E glass can reflect it out to prevent heat from entering the room. For outdoor solar radiation, Low-E glass with a low shading coefficient can be selected to restrict it from entering the room, thereby reducing the cooling cost (air conditioning cost).
22. Which surface of the hollow glass is suitable for the Low-E film layer? Wenzhou fire glass customization
The insulating glass has four surfaces, and the number from the outdoor to the indoor is 1#, 2#, 3#, and 4#, respectively. The area where the heating demand exceeds the cooling demand (Northern Region), the Low-E film is located on the 3# surface. Conversely, the area where the cooling demand exceeds the heating demand (Southern region), the Low-E film should be located on the 2# surface.
23. What is the role of argon in the insulating glass?
Argon gas is an inert gas, and its heat transfer property is inferior to that of air. Therefore, charging into the insulating glass can lower the U value of the insulating glass and increase the heat insulating property of the insulating glass. For Low-E insulating glass, argon also has the effect of protecting the Low-E film layer.
24. What is the negative effect of ultraviolet light?
Ultraviolet light is short-wave radiation that is invisible to the naked eye and accounts for about 2% of the total energy of solar radiation. Ultraviolet rays kill bacteria, but prolonged exposure can burn human skin and eyes, and can also fade furniture and clothing.
25. How much ultraviolet light can Low-E glass attenuate?
Low-E glass reduces UV light by 25% compared to conventional single-piece clear glass. Low-E glass reduces UV light by 14% compared to heat-reflective coated glass. Low-E glass does not completely prevent furniture from fading, but it can slow down fading.
26. What effect does Low-E glass have on indoor plants?
It has no adverse effects on most common plants, and the influence of special rare plants can be consulted by relevant flower experts.
27. Does the sunshade, trees and awnings affect the performance of Low-E glass?
These objects can limit the heat and light entering the room through the glass window, which blocks part of the solar energy transmission, but does not affect the performance of the Low-E glass.
28. Which direction is the Low-E glass installed?
In the winter, no matter which direction the Low-E glass is facing, it does not affect its function, because it mainly reflects the heat inside the room. However, the effect of installation towards the north is good. After all, Low-E glass is somewhat limited in terms of solar radiation while preventing heat loss in the room. l In the summer, Low-E mainly reflects the outdoor heat, so it is suitable for installation in which direction, but the installation in the east, west and south directions is good because it can also reduce the transmission of solar energy.
29. How long does the Low-E film last?
The duration of the coating layer is the same as the duration of the sealing of the hollow glass space layer.
30. What is the effect of combining Low-E glass with tinted glass? Wenzhou tempered glass manufacturer
There are three ways to combine: coating the Low-E film on the colored glass, synthesizing the hollow glass with the colored glass, and synthesizing the laminated glass with the colored glass to further reduce the shading coefficient of the combined glass product, thereby limiting more direct solar radiation into the room. . Therefore, the combination of these three methods is very effective, and is more suitable for use in the warm tropical regions of the South. The use in combination with tinted glass can greatly increase the decorative effect.