Structural Characteristics

Connection Method:Multiple single-span film greenhouses are connected through structures such as gutters to form a continuous large greenhouse space. This structure effectively utilizes land area. Compared to single-span greenhouses, with the same planting area, the enclosing structure area of multi-span film greenhouses is relatively small, thus reducing heat loss and construction costs.

Frame Material:Hot-dip galvanized steel pipes are usually used as the frame material, which has good rust-proof performance and can ensure the stability and service life of the greenhouse structure. The specifications of columns and trusses are generally selected reasonably according to factors such as the span, height, and design load of the greenhouse to ensure that the greenhouse can withstand natural loads such as wind and snow.

Span and Height:The span is generally between 6 meters and 12 meters, with common specifications of 8 meters and 9.6 meters; the height is generally between 3 meters and 5 meters, with a higher ridge height, which is conducive to indoor air circulation and expansion of crop growth space, and facilitates mechanized operation and personnel work.

Covering Material

Film Type:Mainly polyethylene (PE) film is used, which has good light transmission, insulation, and anti-aging properties. Common types include ordinary PE film, long-life film, anti-fog film, and dimming film. Among them, anti-fog film can effectively prevent condensation on the inner surface of the film from forming water droplets, avoiding damage to crops from water droplets, and simultaneously improving light transmission; dimming film can adjust different wavelengths of light according to crop growth needs, providing a more suitable light environment for crops.

Film Thickness:The general thickness is between 0.1 mm and 0.15 mm. Thicker films have stronger wind and tear resistance and a relatively longer service life, but the cost will also increase accordingly; thinner films are lower in cost, but may be slightly weaker in terms of disaster resistance, etc. Users can choose the appropriate film thickness according to their actual needs and usage environment.

Supporting Facilities

Ventilation System:It usually includes top vents and side vents. Top vents generally use a gear-rack drive method, driven by a motor, which can achieve uniform opening and closing of the vents, with a large ventilation area and good ventilation effect; side vents can be controlled by manual or electric film rollers, which are convenient and flexible and can effectively promote air exchange between the inside and outside, adjusting temperature and humidity and gas composition.

Shading System:Similar to multi-span glass greenhouses, there are two types: external shading and internal shading. The external shading system generally uses shading nets with different shading rates. Driven by a motor-driven curtain system, the unfolding and retraction of the shading net can be flexibly adjusted according to the light intensity and crop needs; in addition to the shading function, the internal shading system can also play a certain role in heat preservation at night, reducing heat loss.

Cooling System:The commonly used system is the evaporative cooling system with wet curtains and fans. Wet curtains are installed at one end of the greenhouse, and fans are installed at the other end. During operation, heat is absorbed through water evaporation to lower the indoor temperature, generally reducing the indoor temperature by 3℃-8℃, with significant effects. In addition, a micro-spray cooling system can also be equipped, which atomizes water into tiny particles through nozzles and evaporates heat in the air to achieve cooling, and also increases air humidity.

Heating System:Common ones include heating furnaces and hot air blowers. Heating furnaces generate heat by burning coal, natural gas, fuel oil, etc., and transport hot water or hot air to radiators inside the greenhouse through pipelines to achieve indoor heating; hot air blowers directly blow heated air into the greenhouse, with fast heating speed, and can be flexibly arranged as needed.

Irrigation System:A combination of drip irrigation and spray irrigation is mostly used. The drip irrigation system can accurately deliver water to the roots of crops, saving water and reducing soil water evaporation and weed growth; the spray irrigation system can be used for large-area irrigation and humidity regulation, so that water is evenly distributed above the crops, creating a good water environment for crop growth.

Advantages

Lower Cost:Compared with multi-span glass greenhouses, the construction cost of multi-span film greenhouses is significantly lower, mainly because the Price of covering materials and some structural materials is relatively cheap, which can effectively reduce the initial investment cost for large-scale planting farmers or agricultural enterprises.

Good Insulation Performance:By reasonably selecting film materials and increasing the number of covering layers, as well as supporting insulation measures, such as internal shading insulation curtains, multi-span film greenhouses can maintain indoor temperature to a certain extent, reduce heat loss, and provide a more suitable temperature environment for crop growth.

Easy Installation:The structure is relatively simple, and the installation speed is fast. The time required from foundation construction to the completion of the overall installation is relatively short, and it can be put into use quickly. It is very suitable for the cultivation of some seasonal crops or situations where it is necessary to temporarily increase the planting area.

Adjustable Light Transmission:According to different film materials and usage needs, films with different light transmittance can be selected, and the light transmittance can be further adjusted through shading nets and other facilities to meet the light requirements of different crops at different growth stages.

Applicable Scenarios

Vegetable Planting:Suitable for planting various vegetables, such as tomatoes, cucumbers, peppers, leafy vegetables, etc. It can achieve counter-seasonal cultivation and annual production of vegetables, improve vegetable yield and quality, and meet market demand.

Flower Cultivation:It is often used for seedling raising, cultivation, and maintenance of flowers, providing suitable temperature, humidity, and light conditions for flower growth, which is conducive to flower bud differentiation, growth and development, and quality improvement, and can cultivate high-quality cut flowers and potted flowers.

Seedling Base:As a professional seedling raising place, it can provide a good seedling raising environment for various crops, flowers, seedlings, etc., which is convenient for centralized management and the cultivation of strong seedlings, improving the survival rate and quality of seedlings, and laying a good foundation for subsequent planting production.

Ecological Farming:Can be used for some special breeding that requires higher environmental temperature and humidity, such as breeding snakes, scorpions, turtles, etc., to provide a suitable growth environment for farmed animals, reduce the impact of external environmental changes on farmed animals, and improve breeding efficiency.