Building doors and windows, as the weakest place in the thermal insulation performance of the building, accounts for 51% of the total energy consumption of the building envelope. With the continuous improvement of people's living standards, in order to create a comfortable living environment, indoor refrigeration or mining methods are more and more common, doors and windows as one of the surface envelope structures of the building, directly affect the energy-saving performance of the building, improve the thermal insulation performance of doors and windows is the main way to ensure the energy consumption of the building, and now whether the building adopts energy-saving doors and windows is more and more concerned by people.
Good doors and windows have a good piece of glass. Because glass occupies a very large area in doors and windows, the requirements for it are also quite strict. If the material of the glass is not good, the heat insulation is not good, and the sound insulation is poor, which will produce unnecessary living costs, so that life has no privacy and quietness. LOW-E glass came into being and gradually became the standard configuration of doors and windows. LOW-E glass is low-emissivity glass, which is coated on the surface of the glass, and the emissivity E of the glass is reduced from 0.84 to below 0.15.
What are the magical effects of LOW-E glass installed on doors and windows?
Features of LOW-E Glass:
(1) The infrared reflectivity is high, which can directly reflect the far-infrared thermal radiation.
(2) The surface emissivity E is low, and the ability to absorb external energy is small, so that the heat energy radiated is less.
(3) The shading coefficient Sc has a wide range, and the transmittance of solar energy can be controlled according to the needs to meet the needs of different regions. The LOW-E coating is coated with a silver layer, which reflects more than 98% of the far-infrared thermal radiation, so that it directly reflects heat like a mirror reflecting light. The shading coefficient Sc of the LOW-E can be from 0.2 to 0.7, so that the direct solar radiation energy entering the room can be adjusted as needed.
Coating process of LOW-E glass:
There are two main types: in-line coating, vacuum magnetron sputtering coating (also known as off-line coating). In-line coated glass is manufactured on float glass production lines, which have a single variety, poor heat reflectivity and low manufacturing costs. Its best advantage is that it can be processed by hot bending. The off-line coated glass has a variety of colors, excellent heat reflection performance and obvious energy-saving characteristics. The disadvantage is that it cannot be hot bending.
Characteristics of LOW-E glass:
The LOW-E glass made by the vacuum magnetron sputtering process cannot be used as a single piece, and can only be used as insulating glass or laminated glass. However, its emissivity E is well below 0.15 and can be as low as 0.01. The LOW-E glass manufactured by the online coating process can be used monolithically, but its emissivity E=0.28 can no longer be called LOW-E glass strictly speaking (scientifically the object with an emissivity of E≤0.15 is called a low-radiation object).
Advantages of LOW-E glass in home life:
In winter, the indoor temperature is higher than the outdoor, and the far-infrared heat radiation mainly comes from the interior, and the LOW-E glass can reflect it back into the room to keep the indoor heat from leaking. For part of the solar radiation from the outdoors, LOW-E glass can still allow it to enter the room, and this part of the energy is absorbed by indoor objects and converted into far-infrared thermal radiation and left indoors.
In summer, when the outdoor temperature is higher than the indoor temperature, the far-infrared heat radiation mainly comes from the outdoors, and the LOW-E glass can reflect it out to prevent the heat from entering the room. For solar radiation from the outdoors, LOW-E glass with low shading coefficient can be selected to limit its entry into the room, thereby reducing certain costs and saving costs.
Argon in LOW-E insulating glass :
Argon is an inert gas, and its heat transfer is worse than that of air, so filling insulating glass can reduce the U-value of insulating glass and increase the thermal insulation of insulating glass. For LOW-E insulating glass, argon also has the effect of protecting the LOW-E film.
Attenuation UV function of LOW-E glass:
Compared to ordinary monolithic clear glass, LOW-E glass can reduce ultraviolet rays by 25%. Compared to heat-reflective coated glass, LOW-E glass can reduce UV rays by 14%.