In summer, the load of indoor air conditioning mainly comes from solar radiation, and the main energy consumption of buildings also comes from solar radiation. Effective shading measures must be taken to reduce the air conditioning load and building energy consumption caused by external windows, and the effectiveness of methods such as reducing air infiltration or lowering heat transfer coefficient is limited. So, in the load and energy-saving calculation of air-conditioned buildings, the calculation of shading is very important.
Architectural shading is quite complex, including external shading, window shading facilities, glass shading, and internal shading. These shading measures can all have good effects and can meet the needs of shading when used well.
The external shading of buildings is a very effective shading measure. It can be a building shading structure, such as sun visors, sun visors, eaves, etc; It can also be detachable, such as blinds, movable baffles, flower grids, etc. These sunshade structures are commonly used in traditional buildings.
Reducing the shading coefficient of glass is also a very effective measure. With the development of glass coating technology, glass can now select incident sunlight, introduce visible light into the room, and reflect near-infrared light that increases load and energy consumption. Glass system shading has become one of the main means of shading in modern buildings.
Internal sunshade and window sunshade facilities are also widely used. Sometimes, due to the limitations of building design, the setting of internal sunshade and sunshade facilities is still a necessary selection measure.
The application of these sunshade facilities undoubtedly reduces indoor heat caused by solar radiation, but there is no clear standard for how much reduction and how to evaluate the effectiveness of these sunshade measures.
In the "Energy saving Design Standards for Residential Buildings in Hot Summer and Cold Winter Regions", it is stipulated that the area of external windows (including transparent parts of balcony doors) should not be too large, and external windows should be equipped with movable sunshades; The "Code for Thermal Design of Civil Buildings" stipulates that effective shading measures such as heat reflective glass, reflective sunlight coating, and various fixed and movable shading should be taken for the sunny side of air-conditioned buildings, especially for east and west facing windows; The Design Code for Heating, Ventilation and Air Conditioning stipulates that air-conditioned rooms should minimize the area of external windows and take shading measures. However, none of the above standards provide a definition or calculation method for the shading coefficient. So, how to determine the shading coefficient, especially the comprehensive shading coefficient of the external window after taking many measures, is indeed a problem worth studying and must be solved as soon as possible.
The "Design Standard for Energy Efficiency of Residential Buildings in Hot Summer and Warm Winter Regions" proposes the concept of comprehensive shading coefficient and provides a simplified calculation method for the external shading coefficient of buildings. This article aims to further clarify the relevant concepts of building shading coefficient based on this standard, and conduct a more in-depth analysis of the calculation of shading coefficient, in order to facilitate the solution of related problems in shading facility calculation in the future.

The shading coefficient can be understood as the "shading coefficient of glass", which is usually divided into "comprehensive shading coefficient, shading coefficient of glass" and "shading coefficient of external shading measures", equal to the product of the latter two
2680 is a method for detecting various optical parameters of architectural glass, and the "shading coefficient" refers solely to the "shading coefficient of glass".