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 with 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 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 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 the expansion of crop growth space, facilitating mechanized operation and personnel work.

Covering Material

Film Type:Mainly polyethylene (PE) film is 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 caused 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 have lower costs, but may be slightly weaker in terms of disaster resistance, etc. Users can choose films of appropriate 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 roll-up devices, which are convenient and flexible, and can effectively promote indoor and outdoor air exchange, regulating temperature, 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, which can flexibly adjust the opening and closing of the shading net according to the light intensity and crop needs; in addition to shading, 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, evaporating and absorbing heat in the air to achieve cooling, while also increasing 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 pipes 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 often 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, making water 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 covering materials and some structural materials are relatively inexpensive. For large-scale planting farmers or agricultural enterprises, it can effectively reduce the initial investment cost.

Good Heat Preservation Performance:By reasonably selecting film materials and increasing the number of covering layers, as well as supporting heat preservation measures such as internal shading and heat preservation 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.

Convenient Installation:The structure is relatively simple, and the installation speed is fast. The time required from foundation construction to overall installation completion is relatively short, allowing for quick commissioning. This is very suitable for some crops with strong seasonality or temporary needs to increase 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 year-round production of vegetables, improving vegetable yield and quality, and meeting 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 beneficial to flower bud differentiation, growth and development, and quality improvement. High-quality cut flowers and potted flowers can be cultivated.

Seedling Base:As a professional seedling raising place, it can provide a good seedling raising environment for various crops, flowers, seedlings, etc., facilitating centralized management and seedling raising, 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 suitable growth environment for breeding animals, reduce the impact of external environmental changes on breeding animals, and improve breeding efficiency.