Structural composition of a multi-span arched thin film greenhouse

1. Single arch membrane multi-span greenhouse

The traditional 8430 type multi-span greenhouse is a common membrane multi-span arched greenhouse with a span of 8 meters, a spacing of 4 meters, and a column height of 3 meters. This type of greenhouse is cost-effective and can also be used in conjunction with electrical equipment such as shading and ventilation, making it widely used in southern regions. The investment cost per square meter ranges from 100 to 150 yuan per square meter.

2. Double arch membrane multi-span greenhouse

It is an improved version of the 8430 film greenhouse and has been widely used in northern regions. Adding a layer of arch under the outer arch, the double-layer film has good insulation performance, but slightly poor transparency, making it suitable for cultivation and cultivation. The investment cost per square meter ranges from 160 to 200 yuan per square meter.

Key points for the construction of a multi-span thin film greenhouse

（1） Light intensity

The light intensity of a solar greenhouse is significantly lower than that of an open field, and the indoor high average illumination is generally not higher than 80% of natural light.

（2） Temperature changes

The temperature inside the greenhouse is higher than that in the open field all year round, but the number of winters is shortened. Solar greenhouses can produce seasonal vegetables.

（3） Air humidity

The humidity and relative humidity of the air inside a solar greenhouse are generally higher than those outside.

（4） Changes in gas

In the greenhouse, timely ventilation should be carried out to prevent abnormal CO2 concentration.

（5） Soil environment

The greenhouse soil has high temperature and humidity, and the soil microbial activity is vigorous. Therefore, the conversion of soil nutrients and the decomposition of humus are very fast during greenhouse construction.