Structural Features

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 with single-span greenhouses, for the same planting area, the enclosing structure area of multi-span film greenhouses is relatively smaller, thus reducing heat loss and construction costs.

Frame Material:Hot-dip galvanized steel pipes are usually used as the frame material, which has good anti-corrosion 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 greenhouse span, height, and design load to ensure that the greenhouse can withstand natural loads such as wind and snow.

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

Covering Material

Film Type:Polyethylene (PE) film is mainly used, which has good light transmittance, heat preservation, 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 dew condensation on the inner surface of the film from forming water droplets, avoiding damage to crops by water droplets, and improving light transmittance; 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 resistance and tear resistance, and a relatively longer service life, but the cost will also increase accordingly; thinner films are cheaper, 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 adopt a gear-rack drive method, which can be driven by a motor to 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 roll-up devices, which are convenient and flexible, and can effectively promote indoor and outdoor air exchange, and regulate temperature, humidity, and gas composition.

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

Cooling System:The commonly used system is the evaporative cooling system, which installs evaporative pads at one end of the greenhouse and fans at the other end. During operation, the evaporation of water absorbs heat to reduce the indoor temperature, which can generally reduce the indoor temperature by 3℃-8℃, with a significant effect. In addition, a micro-spray cooling system can also be equipped, which atomizes water into tiny particles through nozzles, evaporates and absorbs 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 the hot water or hot air is transported to the radiators in the greenhouse through pipelines to achieve indoor heating; hot air blowers directly blow the heated air into the greenhouse, which heats up quickly and can be arranged flexibly according to needs.

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, reducing soil water evaporation, and weed growth; the spray irrigation system can be used for large-area irrigation and air humidity regulation, so that water is evenly distributed above crops, creating a good moisture 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 covering materials and some structural materials are 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 and insulation curtains, multi-span film greenhouses can maintain the 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 overall installation completion is short, and it can be put into use quickly. It is very suitable for planting some seasonal crops or temporarily increasing the planting area.

Adjustable Light Transmittance: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 off-season 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. It can cultivate high-quality cut flowers, potted flowers, etc.

Seedling Base:As a professional seedling raising place, it can provide a good seedling raising environment for various crops, flowers, seedlings, etc., making it easy to centrally manage and cultivate strong seedlings, improve the survival rate and quality of seedlings, and lay 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 suitable growth environment for breeding animals, reduce the impact of external environmental changes on breeding animals, and improve breeding efficiency.