The previous article “Low-E glass of those things (above)” said:

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

LOW-E glass reducing the secondary radiation heat transfer brought by solar radiation by the low absorption rate of solar radiation (solar radiation), and the low absorption rate (low radiation) and high reflection rate of far-infrared radiation, reduce far away Infrared radiation heat transfer greatly improves the insulation performance of glass (glass heat transfer coefficient K value);

By reducing the low absorption of solar light (solar radiation), the secondary radiation heat transfer brought by solar radiation, and the high reflection of solar light (solar radiation) to reduce solar radiation directly through heat transfer, which can more effectively improve the glass Thermal insulation performance (the sun’s thermal coefficient SHGC, or the shade coefficient SC);

In this issue of “Those things (below)”, how can we buy and have any precautions to talk about:

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

01 Is it good to look at the heat insulation and thermal insulation performance parameters?


The first is because the requirements of the glass insulation performance (heat transfer coefficient K value), thermal insulation performance (the sun thermal coefficient SHGC, or sunshain SC) requirements depend on the function of different geographical climate and buildings.

For example, in the northern cities, it pays more attention to thermal insulation performance than in the southern cities. For example, “summer is hot, and my sun room is the highest frequency during the day”, it means that the insulation performance of glass should be lower than other positions.

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

The second is because the characteristics of the Low-E glass (can reduce the heat transfer through the solar radiation), and can also be dug deep.

Because LOW-E glass is very different from other energy-saving glass, it can have a high visible light transmission rate of solar radiation, and low infrared radiation through the rate (other glass can only be consistent), so if it is thinner, it will be thinner. Study its insulation performance parameters, after watching the sun thermal coefficient (SHGC, or sunshain SC), and you can also understand the total transmission ratio (GIR) of the solar infrared thermal energy.

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

02 What is the total transmission ratio of the sun infrared thermal energy (GIR)

The sun thermal coefficient (SHGC, or sunshain SC) is a recognized parameter that measures glass thermal insulation. It is used to measure the energy that contains ultraviolet, visible light and infrared rays through energy.

It is very accurate to the thermal insulation performance of transparent glass, color -colored glass, and sunlight -controlled coating glass, because the solar spectrum of these glass is basically a straight line through the curve (below ▽) Equally, different glass can be compared on the same basis to distinguish relatively high and low.

However, it is not fair to measure the LOW-E glass thermal insulation performance, because for the impact of the energy conservation of the building, the thermal effect of the visible light is very low, and the thermal energy of infrared the infrared is the main. LOW-E glass is “visible radiation can be high, and infrared radiation can be low” (ie, below ▽).

Because thermal energy comes mainly from infrared radiation, if a Low-E hollow glass is the same as the heat coefficient of the sun (SHGC, or the sunshain coefficient SC) of a three-glass and two-glass cavity glass, it is likely to LOW-E hollow glass The actual heat insulation effect will be better.

In order to more accurately measure the thermal insulation performance of all glass, there is a more accurate measurement parameter -the total transmission ratio of the sun infrared thermal energy (GIR):

The total transmission ratio of the solar infrared thermal energy, that is, in the ranges of the sunlight near the infrared band of 780-1500 nm, directly absorb the part of the solar energy through the glass of the solar passage through the glass of the glass. The ratio of intensity;

(△ The total transmission of the sun infrared thermal energy is lower than that the more the value represents the more thermal insulation performance.

03 What is double silver and three silver Low-E?

Multi-silver is mentioned here, mainly because the “Sun Infrared thermal Energy Total Pamentation ratio (GIR)” in the previous chapter not only reflects the LOW-E glass and the non-LOW-E glass-the sun thermal coefficient (SHGC, or the SHGC, or The same is the same as the sedan coefficient SC), but the actual heat insulation effect is good.

It also illustrates why the multi-silver LOW-E glass is better thermal insulation performance:

Ordinary offline LOW-E contains only single-layer silver film. Double silver and three silver can be directly understood as an upgraded version of single silver LOW-E (superimposed silver film layer);

Multi -silver can block more solar infrared radiation through, that is, stronger thermal insulation performance (whether it is the sun thermal coefficient SHGC, sunshade coefficient SC, or the solar infrared thermal energy total transmission than GIR);

Multi -silver radiation rate is lower, so the heat transfer coefficient also improves (it is not as improved as the thermal insulation performance is improved);

(△ Multi-silver Low-E glass structure diagram;)

(Simple performance comparison of single, double, and three silver;)

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

04 How to choose Low-E glass in my family

The theoretical concept of performance is over, and the next is the application.

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

What kind of performance indicators need “My Glass”, how to choose according to the performance indicators:

First of all, it is clear that the performance of the insulation and thermal insulation of doors and windows (glass), the premise of discussion must be the feeling of use after closing the window closing. Therefore, the habit of the home is always opening the window to ventilate, and there is no big heat insulation insulation, or there is basically no one during the day, and there is no big heat insulation (to control the solar radiation during the day);

Secondly, the two parameters of thermal insulation performance (heat transfer coefficient K value) and thermal insulation performance (sun thermal coefficient SHGC) are often interconnected (such as when the K value is low, the lower the SHGC) “(Otherwise, there is no need to say);

In general, the insulation performance parameters are generally introduced by the sun thermal coefficient (SHGC, or sunshain SC) with the sun, as mentioned in most cases mentioned above. If the theoretical heat insulation effect between LOW-E glass and non-Low-E glass, you may use the total transmission ratio of the sun infrared thermal energy (GIR);

And, in fact, no matter which climate, the more K value of thermal insulation performance is undoubtedly the better, but it is not worth the money to reduce the K value (the more cold the cold time in winter, the high heating cost is high in heating costs, the higher the heating cost is high in heating costs. The more valuable, what kind of thermal insulation in Chuncheng Kunming);

For most areas, the heat insulation performance is useful for summer, and is not friendly to winter (need sunlight heating in winter, the heat of the sun cannot enter the room, and this part of the heat is missing). The fans said that the bedroom in the house was installed with LOW-E glass, because its personal habits like to expose the quilt, but the quilt is not hot in the sun;

In the west -sun room, the glass shade coefficient can be selected lower, and the heat of the solar in the winter will also control the heat insulation effect most of the time. The northern room can also choose LOW-E glass because it can play the effect of insulation (reflect far-infrared radiation);

Finally, some general data and reference are given. In terms of thermal insulation performance, you can refer to the Chinese architectural heat worker data partition diagram in the figure below:

The entire window K value in cold areas such as Beijing Tianjin is best around 1.5 ~ 2.0, and the entire window K value in summer, Zhejiang, Shanghai and other summer -hot winter cold areas is best at about 2.0 ~ 2.5, Yunnan Guangdong and other gentle climate, summer hot and winter warm areas in heat insulation demand Not high, the entire window K value is around 2.5 ~ 3.0;

The thermal insulation performance of the entire window is different from the single glass K value. In short, if the window wants to achieve this performance, the performance of the glass must be higher;

For example, in the solution proposed by the local standards of Beijing (below 1.1 of the entire window K value requirements), its glass K value is 0.77, and the three-glass and two-cavity dual LOW-E glass is used. In the solution of the entire window K value in Jiangsu, its glass K value is 1.45, and the hollow LOW-E glass is used;

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

(△ China Building Heat Data Data Partition Map;)

(△ The entire window product solution;)

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

In terms of thermal insulation:

Beijing Tianjin and other cold regions have long heating time in winter. The air -conditioning time used in summer is short. You can consider choosing a glass with the sun thermal coefficient SHGC> 0.5, or the sunshade coefficient SC> 0.6 (the sunshade coefficient SC can be transformed with the sun thermal coefficient SHGC. Shgc = 0.87 sc);

The air conditioners used in summer and warm and winter warm areas in Hainan, Guangdong for a long time, and not heating in winter. You can consider choosing to use the sun thermal coefficient SHGC <0.25 (SC <0.3);

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

Jiangsu, Zhejiang and Shanghai and other summer hot and winter -cold areas need air -conditioning refrigeration in summer. In winter, heating heat is required. The heat coefficient of the sun is more suitable between 0.25 and 0.5 (SC is 0.3 ~ 0.6). Choose a little lower, the cooling time and cost are lower than the heating, the coefficient is higher;

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

(△ Glass conventional performance parameters;)

05 Why is there no LOW-E clamping glass

Because the LOW-E film layer is in a ticing layer, the performance is poor.

Only when the LOW-E film layer is in contact with the air can the heat exchange between the glass surface and the air can effectively reduce the thermal insulation effect, so the two products are not put together. (Online LOW-E or silver LOW-E film can be used as an outer glass surface, which will have the heat insulation and thermal insulation effect.

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

Plason, LOW-E clamping adhesive heat insulation, and poor thermal insulation performance, and also answered ▽

06 Why do door and window merchants often recommend Low-E hollow glass

Low-E glass things (above) mentioned that there is also a combination of 1 + 1> 2 in the door and window of home improvement, which is Low-E coating + hollow glass. The smallest and most cost -effective one.

Doors and windows merchants often recommend that you use LOW-E hollow glass when you propose the demand for heat insulation and insulation.

The effect is ideal. LOW-E hollow glass thermal insulation is similar to that of the three glass cavity.

The price is affordable. The cost of adding LOW-E per square meter in hollow glass is about 50 ~ 100 yuan, which is more affordable than the three glass cavities;

Easy to use, the effect of a layer of film is also light and light, which is convenient for transportation and installation (provincial artificial). It is also convenient for design and subsequent use. The door glass is free to use lightly);

07mew-E hollow glass, which side of the membrane layer is suitable

Low-E glass is most commonly used with hollow glass. The membrane layer position is somewhat particular:

The offline LOW-E film is located on the surface of the hollow glass, which is No. 2 or 3 (the three-glass cavity may still be 4 or 5);

Each hollow layer of hollow glass is needed to have a LOW-E film, and both sides can not significantly improve energy saving performance (so three glass and two cavities can be dual-e, and double Low-E refers to two. The membrane surface is coated, different from double silver);

The production and installation location of the membrane layer has an impact on the performance of thermal insulation (about 10 ~ 15 %). If the southern cities may pursue the heat insulation effect, the membrane layer is suitable for the outdoor side (No. 2 or 4). The demand for solar heat in winter is higher than the heat insulation in the summer, and the membrane layer is suitable for the outdoor side (No. 3 or No. 5);

(Naming the location of the film layer of the △ LOW-E film;)

(△ LOW-E film layer position affects thermal insulation performance;)

08 Life of the use of large-time LOW-E glass

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

Home-oriented doors and windows, basically LOW-E glass is made into hollow glass. Therefore, in most cases, the problem of use of LOW-E glass is the problem of valid time limit for the use of hollow LOW-E glass:

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

Inside the qualified and compliant hollow glass, the air is dry, and the dew point is very low (-40 ° C, the interior dew inside the hollow glass represents the use of glass failure). Low-E film use in such an environment is stable. In theory, it can be effective with the life limit of hollow glass;

The above premise requires that there is no problem with coating. Low-E hollow glass production process is standardized. The quality of the finished glass is good;

And if the Low-E glass original tablets are not saved in time or reasonably, the inferior LOW-E glass original tablets (thin protective film, etc.), the part of the sealant during production is not removed or thorough. The membrane is scratched, or the problem of the production of hollow glass (the difference in sealing, unevenly coating of butyl gum, too poor quality of intervals, etc.) can cause the effective service life of the hollow LOW-E glass Short short (a lot of invalidity in two or three years);

Therefore, when consumers buy a hollow LOW-E glass, they must first confirm the quality of the glass by asking the merchant “which glass deep processing is and what supply chain is used”;

And improving the glass configuration to ensure the effective service life. For example, the empty layer of the hollow glass is added into an inert gas (prevention of oxidation), and the bend partition strip instead of the intervening interval bar, and using the new interval bars such as TPS instead of the traditional interval strip;

Or ask the merchant, “Do you provide a large-time LOW-E hollow glass for use? How many years of warranty?”

09 inert gas and Low-E glass complement each other

Low-E hollow glass in the middle of the empty layer, filling ordinary air into an inert gas filling, which has the following effects:

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

Performance complement each other, and inert gas also helps improve the heat insulation and thermal insulation effect (reduce thermal conduction, etc.);

The inert gas helps prevent the LOW-E silver film layer of oxidation, and improve the effective service life of LOW-E hollow glass;

Therefore, when ensuring that the finished glass you buy is guaranteed, the two are selected for the performance.

010 Low-E hollow glass mid-space interval thickness selection

LOW-E hollow glass’s hollow layer thickness selection, the principle is the same as the previous content of “Pengge Door Door Science”. Generally, 9 A ~ 15 A is appropriate (except for special circumstances such as large glass). Essence

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

(Comparison of the 6 -mm hollow glass gas layer and thermal insulation performance;)

(△ Low-E hollow glass K value changes with the thickness of the air layer;)

011Low-E glass anti-ultraviolet rays?

The previous content “LOW-E Glass’s spectral curve” can be explained that Low-E can attenuation of UV rays, but not completely isolated.

Related data proves that there are differences between different varieties of different varieties of different varieties of the LOW-E glass attenuation. Generally, the ultraviolet light transmission rate is between 9 % and 35 % (the scenes that need to be isolated from ultraviolet rays in the study can be considered using tape glass).

012 Low-E glass transmittance

LOW-E glass light transmittance related content:

LOW-E glass light transmission performance parameters can be seen visible light transmission ratio, also known as light transmittance. The higher the light transmission rate, the more helpful the indoor lighting. Generally, it can be divided into three types: high, medium, and low (more than 70 %, 50-60 %, 50 %, and below);;

LOW-E glass light transmission rate has no effect on thermal insulation performance, which has a certain effect on thermal insulation performance. The lower the light transmission rate, the relatively better the thermal insulation performance (the sun thermal coefficient SHGC = sunlight direct transmission ratio+ indoor secondary time indoor secondary time Passing heat, the ratio of solar light is more transmitted than the ratio of solar radiation intensity to the intensity of incident);

LOW-E glass is not as good as white glass (the light transmission rate is about 85 % -90 %). Generally, the most considers at home is the LOW-E glass with a high light transmission rate. Applications are mostly;

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

The reverse side of the light transmission is the reflectivity, so the lower the light transmission rate to a certain extent, the better the glass privacy is (not expanded here, open a article in the future);

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

LOW-E glass transparentness is quite different on the lighting and difference in the lighting of the home. Consumers recommend more at the merchant when buying, or “observe” the real objects on the construction site, and then make a decision;

013 Low-E glass color

There are many colors that LOW-E glass can be made. It depends on the original film (manufacturers, types, substrates, etc.) purchased by the glass deep processing manufacturers. Do you make a choice again:

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

(△ Picture comes from the Banbin Glass Blog;)

Low-e玻璃那些事下 | Low-e玻璃怎么选购?使用有什么注意事项?

014 LOW-E glass Simple identification method

Finally, consumers bought Low-E glass, how to verify that there is no “drop package” when receiving the goods:

Method 1: Look at the glass label. In most cases, the glass label will clearly write the specific configuration of this glass.

Method 2: Use flashlights, or lighters and other lighting objects to take one shine on both sides of the glass. Observe the glass light spots shot under multiple angles. It

You might also enjoy: