The color of glass curtain wall

Glass curtain walls have been present in the United States since the 1950s and 1960s. They have lasted for more than half a century. With the development of glass production and processing technology, the use of glass curtain walls has become more common. The Yiyi Building, the first all-glass curtain wall building that appeared in Shanghai in the 1980s, marked the birth of a glass curtain wall in China. Today, there are hundreds of glass curtain wall structures in Shanghai alone, and there will be a large number of glass curtain wall buildings.

With the development of glass deep processing technology, glass curtain walls become more energy-efficient, environmentally friendly and safe. In addition, glass curtain walls can effectively obtain natural light and reduce the energy consumption of indoor lighting. They also have the function of sheltering and decoration, which not only reduces the weight of the building, but also protects wind and rain. Make the building integrate into the surrounding environment and establish an external image full of personality and color. These advantages determine the wide use of glass curtain walls and become the dominant external maintenance material in the construction market.

The glass curtain wall in the building has many advantages mentioned above. However, choosing the glass curtain wall with suitable colors is a subject that needs serious consideration. The color of the curtain wall glass of a building is unique compared to the color of other materials. As a technician in the glass industry, it is necessary to analyze the color characteristics of the curtain wall for reference by architects and colleagues.

The so-called color includes two kinds, one is the direct action of the color light and our visual system, resulting in the so-called non-correlated color, and the other is the interaction of the light source and the material to generate the colored light, ie, the relevant color is obtained. Although we can easily associate color with an object, the interaction of the light source, the object, and the observer ultimately determines the color of the object. Changing one or more factors will cause the color to change dramatically. An artificially colored light source produces a non-correlated color (transmission color); in a building, light enters the room through the doors and windows of the building, and the color of the transmitted light is a non-correlated color; the colors of buildings that people see in the city are After the sun and the exterior decoration of the building reflected sunlight, the colors we observed were related colors, so the color of the building changed with different weather conditions, different seasons, and different observers.

In addition to glass, most other materials, such as stone, metal, and cement, are mostly non-transparent materials. The color of these materials we usually see is mainly the result of colored light that our eyes feel after they reflect some specific spectrum of sunlight. Ntgii! The color of the materials is relatively fixed and simple relative to glass. Usually the colors we see in natural light are closer to the colors we see on buildings, but in different seasons and climates, due to the solar spectrum and The intensity change will be slightly different and is a single correlated color.

The color of the glass curtain wall is not so simple; the color of the low-reflectivity glass curtain wall in the visible light that is more popular at present is compared with the color conditions of the exterior decoration materials such as stone and aluminum plates, and the colors expressed are more special, and the changes are more and more. Not fixed, for this reason, we analyze the different characteristics of the color of the glass curtain wall of a building and other materials. We hope to use a reasonable combination of the curtain wall glass and other colors of building materials to make the appearance of the building more attractive and more attractive. People's eyeballs help.

Those who work in the construction of glass curtain walls often have such doubts. The glass sample and the glass curtain wall that was finally installed on the building are very different in color. Even under the same weather conditions, it is almost always What are the reasons for the difference?

The answer to the question starts with the characteristics of glass, which is usually a light-transmitting material, but at the same time, the glass is a mirror-reflective material. The inherent duality of the transmission and reflection of light affects the glass curtain wall of the final building. The color of the curtain wall glass that we eventually see is the color that is reflected in our eyes by the combined effect of related and unrelated colors.

We first briefly define some concepts. First, we define T as the visible light transmittance of the glass material, then define R as the visible light reflectivity of the glass material, the third definition Ab as the visible light absorption rate of the glass material, and the fourth will enclose the glass curtain wall structure. The condition of the internal environment is defined as the depth of field. Internal environment The physical wall and the glass curtain wall have a large space and a deep depth of field; the spacing is small and the depth of field is shallow. When the depth of field is deep, the appearance gives a dark, dark color; the depth of field is shallow, the appearance gives a feeling of lightness, and the color is light.

When a beam of sunlight hits a piece of glass, the total amount of 100% sun light = glass transmittance (T) + glass reflectivity (R) + glass absorptivity (Ab). When the absorptivity of the glass is fixed, the transmissivity and reflectivity of the glass are usually in a complementary relation. When the reflectance is increased, the transmissivity is necessarily reduced. On the contrary, when the reflectance is decreased, the transmissivity is bound to increase. Because the color of glass that people usually see is the result of the combination of visible light transmittance and reflectivity of glass. Therefore, careful analysis of differences in the color performance of curtain wall glass with different transmittances and reflectivity makes it easier to use glass curtain walls and others. The construction materials are reasonably matched.

In the following, we analyze the variation of glass color from two aspects of visible light transmittance and reflectivity, so that we can easily grasp the color of the glass curtain wall.

Firstly, the effect of the visible light transmittance of glass on the external color of glass is analyzed. The higher the visible light transmittance of glass is, the more severe the influence of background color is, and the greater the influence of background depth change, and vice versa, the visible light transmittance of glass. The lower: the more affected by the background color, the less affected by the change in background depth of field. For example, the window glass of ordinary houses uses 5mm monolithic white glass, its visible light transmittance is 88%, the entire building window area is very small, the color of the outer viewing glass is a black block, very heavy and dark; while the early use of large The glass curtain wall made of solar control film glass has a very low visible light transmittance. Therefore, we can hardly see the indoor environment. The glass curtain wall is beautiful and light, and the colors are lighter.

Second, the effect of the visible light reflectivity of the glass on the external color of the glass is analyzed. The higher the visible light reflectivity of the glass, the lighter the glass color; on the contrary, the lower the visible light reflectivity of the glass, the darker the glass color; from the lighting and color From the academic point of view, the high visible light reflectance means that under the same illuminance, the brightness of the glass is high and the color reducibility is poor: the visible light reflectivity is low, which means that under the same illuminance, the brightness of the glass is low, and the color reducibility is good: therefore, there is the aforementioned result. . The silver mirror glass has a visible light reflectance of 82% or more. As long as this visible light reflectance is maintained, it almost gives us a feeling of silver and glitter. If you want to obtain other colors of silver mirror glass, then it is bound to need to reduce its visible light reflectivity to be able to achieve.

Third, after analyzing the effect of the visible light transmittance and reflectivity of the glass on the external color of the glass, considering that the glass usually has both visible light transmittance and reflectance, we need to analyze the effect of synthetic visible light transmittance and reflectance on the color of the glass. Afterwards, how to choose the right curtain wall glass.

High visible light transmittance reflectivity and high visible light transmittance low reflectivity products, in which case the visible light transmittance plays a dominant role in the influence of the color of the product. What we mainly see is the non-correlated color (transmission color) of the glass and The color appearing under the influence of the depth of field, at this time, other materials matched with the glass curtain wall need to select the light and bright colors of the same color system. However, in areas where sunny weather dominates throughout the year, when the depth of field is shallow, if the visible light reflectance and transmittance of the glass are high, other materials of the same color and relatively heavy colors can be selected to match the curtain wall glass. : At this time, the sunlight as the light source is bright and the reflectivity of the glass is high. The related color (reflection color) plays a role, and the non-correlated color (transmission color) does not change. Therefore, the color of the curtain wall glass will appear slightly lighter. . This building has a sense of hierarchy and rich facades.

Low visible light transmittance High reflectivity glass. The glass is lighter and lighter in color. Choose other materials that match the glass curtain wall. You need to select materials with the same color and lighter color, so that the entire building curtain wall has a good integration effect. The texture of the curtain wall glass is strong. If you need a clear sense of the depth of the curtain wall, choose a matching material that is dark and heavy in the same color.

Low-viscosity, low-reflectivity glass, where the glass's own color (non-correlated color) plays a dominant role in the color of the outside view, and is almost unaffected by the background depth of field. The curtain wall glass has good shielding properties; this time with glass. Other materials used in the curtain wall need to be selected in the same light and light colors so that the building does not appear to be overly heavy and boring.

For a building that adopts a full-glass curtain wall, if the glass has a medium-to-high visible light transmittance and a relatively low visible light reflectance product, the facade of the window wall is also a glass. Most people think that a configuration is used. When glass is used, the color of the entire facade can be ensured, and the result is often counterproductive. The apparent inconsistency between the visible and invisible parts is due to the fact that the influence of different background depths of field on the external color of the glass is not taken into consideration. A glass product with a low visible light transmittance, a slightly lower reflectance, and a deeper color should be used in the window wall area. This just compensates for the difference in color between the visible and non-visible parts due to different background depths of field.

In view of the above, the principle of building glass selection, taking into account the visible light transmittance of the glass, visible light reflectance and background color and depth of field of the stack of three factors, select the appropriate glass products. From the perspective of energy saving and comfort, it is recommended to select a transmission color (non-correlated color) as a neutral color, and a product with a moderate visible light transmittance and a visible light reflectance of about 20% is most reasonable.