1 What are the main composite products of glass?

There are mainly tempered, semi-tempered, sandwich, insulating, coated, and their different combinations. For example, tempered coated insulating glass, coated laminated insulating glass, etc.

2 What is the shading coefficient Sc, and which part of the heat transfer does it reflect?

 Shading coefficient Sc: Under the same conditions, the ratio of solar radiation energy transmitted through glass to the solar radiation energy transmitted through 3mm transparent glass. The solar radiation energy through 3mm transparent glass is 630w/m2.     

Shading coefficient Sc = direct solar radiation energy ÷ 630w/m2

Direct solar radiation energy = 630w/m2×Sc The shading coefficient reflects the heat transfer of direct solar radiation through the glass.

3 Is a high or low shading coefficient Sc better?

Glass with different shading coefficients is suitable for areas with different climates. The shading coefficient is high, and more solar radiation enters the room through the glass windows, thus reducing heating costs in winter. This kind of glass is suitable for use in northern areas with long winters. The shading coefficient is low, and the blocking effect on direct solar radiation is good, which can reduce the direct solar radiation energy entering the room. This kind of glass is suitable for use in southern areas where summer is long.

 4 What is the U-value? What part of the heat transfer does it reflect?

The U value reflects the heat energy transmitted through the glass due to convection and conduction, including the heat energy absorbed by the glass and then radiated outward. Therefore, the emissivity E of the glass is low, and the U value is correspondingly low. Convection heat energy = U value × (T outdoor - T indoor) T outdoor and T indoor are the indoor and outdoor temperatures respectively.

 5 How many components does the total heat energy transferred through glass consist of? How to express?

It consists of two parts: direct solar radiation heat transfer and convection conduction heat transfer.

Expressed as Q total = 630 × Sc + U × (T outdoor__-T indoor)

6 What parts does solar radiation consist of?

Consisting of three parts: ultraviolet radiation, with a wavelength range of 0.01 to 0.38 micrometers. The visible light wavelength range is 0.38 to 0.75 microns. Near infrared radiation, with a wavelength range of 0.75-3 microns.

 7 Does far-infrared thermal radiation come directly from the sun?

Far infrared thermal radiation indirectly comes from the sun, and this part of the energy is thermal energy. It is absorbed by objects after being irradiated by the sun and then radiated out. Its wavelength range is distributed between 3 and 40 microns. In summer, the far-infrared thermal radiation emitted by outdoor roads and buildings under sunlight is one of the main heat sources from outside.

 8 Is there far-infrared heat radiation indoors?

Yes, indoor far-infrared heat radiation comes from heaters, household appliances, furniture exposed to sunlight, stoves and the human body. It is the main heat source from indoors in winter.

 9 How does far-infrared heat radiation pass through glass?

Far-infrared thermal radiation cannot be directly transmitted through ordinary glass and can only be absorbed or reflected by the glass. After the glass absorbs this part of the energy, its temperature will rise, and it will dissipate this part of the energy through convection and conduction with the air and re-emitting thermal radiation to both sides. Therefore, this part of the energy eventually passes through the glass, but it is absorbed first and then radiated. way through.

 10 How to distinguish between far-infrared heat radiation and near-infrared radiation?

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 objects. Far-infrared thermal radiation, as a result of solar energy conversion or artificial production, is itself heat. If you look at a road under sunlight in summer, you can see thermal radiation waves rising from the ground (that is, solar energy is being converted into thermal radiation). In winter, you can directly feel the heat radiation if you are close to the heater.

 11 What is Low-E glass?

Low-E glass is low-emissivity glass. It is formed by coating the glass surface to reduce the emissivity E of the glass from 0.84 to below 0.15.

 12 What are the characteristics of Low-E glass?

Low-E glass has the following characteristics:

* It has high infrared reflectivity and can directly reflect far-infrared heat radiation.

* The surface emissivity E is low, and its ability to absorb external energy is small, so it re-radiates less heat energy.

* The shading coefficient Sc has a wide range, and the amount of solar energy transmitted can be controlled as needed to adapt to the needs of different regions.

 13 Why does Low-E coating reflect heat?

The Low-E film layer is coated with silver, which can reflect more than 98% of far-infrared heat radiation, thereby directly reflecting heat like a mirror reflecting light. The shading coefficient Sc of Low-E can be from 0.2 to 0.7, so that the direct solar radiation entering the room can be controlled as needed.

 14 What is heat reflective glass?

Heat reflective glass is commonly known as coated glass. It is formed by coating the glass surface to reduce the shading coefficient Sc of the glass from 0.98 (6mm transparent glass) to 0.2~0.6.

 15 What is the functional difference between Low-E glass and heat reflective glass?

Heat-reflective glass reduces the shading coefficient of the glass and limits direct solar radiation from entering the room through the glass, thereby reducing air conditioning costs and saving energy. Low-E glass reduces the U-value of the glass and limits the penetration of far-infrared heat radiation through the glass, thereby reducing the amount of convective heat energy transmitted through the glass. At the same time, the shading coefficient Sc of Low-E glass has a wide adjustment range, which can effectively control the direct solar radiation entering the room.