External shading systems can be installed on the roofs of steel structure buildings. By using external shading, the indoor environment can be modified, and by regulating the indoor temperature, the environmental requirements necessary for plant growth can be met. 

      If there are no columns or suitable installation positions for external shading on the roof of a steel structure building, it is necessary to conduct an on-site assessment to determine whether the basic installation conditions are met. If the column base installation location does not meet the requirements, external shading cannot be installed. The installation of external shading for the Wuhan hydroponic greenhouse was based on the modification of the column bases used for installing photovoltaic panels on the steel structure roof, making them meet the usage requirements and thus designing an installation plan that could be implemented. During the subsequent installation process, improvements and optimizations were made based on actual conditions. When constructing new external shading, it is essential to plan the design in advance and match it according to the dimensions measured on-site. If the dimensions are consistent, the frame can be prefabricated in the factory and installed on-site. If the dimensions vary, on-site welding or the use of connecting components may be required. When installing external shading on glass-roofed structures, welding is generally not recommended because the splatter of molten iron during welding can crack the roof glass, causing unnecessary damage. It is advisable to use bolted connections instead.