Greenhouse is daylighting building, so light transmittance is the most basic index to evaluate the transmittance of greenhouse. Transmittance refers to the percentage of light and outdoor light in a greenhouse. The transmittance of greenhouse is affected by light transmittance and the shadow rate of greenhouse skeleton, and the transmittance of greenhouse is changing with the different seasons of solar radiation. The light transmittance of greenhouse becomes the direct influence factor of crop growth and selection of crop varieties. In general, even a plastic greenhouse in $number, glass greenhouse light transmittance in $number, solar greenhouse can reach more than 70%.
Heating energy consumption is the main obstacle of greenhouse winter operation. It is the most direct means to improve the efficiency of greenhouse production to improve heat preservation performance and reduce energy consumption. The heat preservation ratio of greenhouse is a basic index to measure the heat preservation performance of greenhouse. Greenhouse thermal insulation ratio is less thermal resistance of greenhouse cover area and thermal resistance of greenhouse cover structure coverage area of the ratio of the same area. The larger the insulation ratio, the better the thermal insulation performance of greenhouse.
The heat preservation performance of greenhouse is very good, heating energy consumption is the main obstacle of the greenhouse in winter, it is the best method to improve the heat preservation performance and reduce energy consumption of greenhouse.