|The greenhouse is a daylighting building, so the light transmittance is one of the most basic indicators for evaluating the light transmission performance of the greenhouse. Light transmittance is the percentage of light that penetrates into the greenhouse and the amount of outdoor light. The light transmittance of the greenhouse is affected by the light transmission performance of the greenhouse light-transmitting cover material and the shadow ratio of the greenhouse skeleton, and the light transmittance of the greenhouse is also changing with the different solar radiation angles in different seasons. The light transmittance of the greenhouse is a direct influencing factor for crop growth and selection of crop varieties. Generally, the multi-span plastic greenhouse is 50%~60%, the light transmittance of the glass greenhouse is 60%~70%, and the solar greenhouse can reach more than 70%.|
Heating energy consumption is a major obstacle to the winter operation of the greenhouse. Improving the insulation performance of greenhouses and reducing energy consumption are the most direct means to improve the efficiency of greenhouse production. The insulation ratio of the greenhouse is a basic indicator for measuring the insulation performance of the greenhouse. The greenhouse insulation ratio refers to the ratio of the coverage area of the greenhouse light-transmitting material with less thermal resistance to the sum of the coverage area of the greenhouse enclosure structure with larger thermal resistance. The higher the insulation ratio, the better the insulation performance of the greenhouse.
Greenhouse construction must consider its durability. Greenhouse durability is affected by factors such as the aging resistance of greenhouse materials and the carrying capacity of the main structure of the greenhouse. In addition to its own strength, the durability of the light-transmitting material is also manifested in the fact that the light transmittance of the material is continuously attenuated with time, and the degree of attenuation of the light transmittance is a decisive factor affecting the service life of the light-transmitting material. Since the greenhouse operation is in a high temperature and high humidity environment for a long time, the surface anti-corrosion of the components becomes one of the important factors affecting the service life of the greenhouse.