2026-11-04
Multi-span plastic greenhouses enable high crop yields
With the rapid development of global agriculture, commercial cultivation faces a significant challenge: how to maximize crop yields through environmental control while effectively managing costs. The Zheyang engineering team conducts in-depth work on structural design, the evaluation of covering materials, and integrated environmental control systems to better meet the specific requirements of cultivation. Below, we take the multi-span plastic greenhouse as an example to illustrate this approach.
Compared to traditional greenhouses, Zheyang Engineering—a professional agricultural greenhouse manufacturer —has increased the gutter height to 5.5 meters, with a total ridge height of 7.5 meters. This design expands the internal air volume by 40% to 60%. During the midday heat in summer, the superheated air naturally rises into a buffer zone well above the growth points of the hanging crops, preventing the tender tips from scorching. At night, this large volume of air acts like a natural thermal blanket, ensuring a gradual and steady drop in temperature; this helps prevent issues such as the shedding of blossoms and fruit, or the development of stunted, underdeveloped fruit, which are often triggered by sudden temperature plunges.
Greenhouse covering materials serve as the "energy gateway" for crops. Moving away from simplistic or indiscriminate selection methods, we provide tailored, high-quality covering solutions for our clients—carefully matched based on regional solar radiation levels and the specific types of crops being cultivated:
5-layer co-extruded multifunctional PO film:
- Thickness specification: 150–200 μm
- Light transmission: 89%–91%
- Astigmatism rate: 50%–65%
- Long-lasting anti-drip and anti-fog properties: Nano-coated type (3–5 years)
- Service life: 5–7 years
- Applicable scenarios: High-yield fruit and vegetable crops, premium berries, commercial seedling production
Direct sunlight often causes "light saturation" or even sunburn on the upper leaves of crops, while the mature leaves in the middle and lower sections remain in a state of "starvation" and dormancy due to constant shading. The Zheyang Engineering Team utilizes specially selected, highly diffuse-reflective PO films to transform intense, direct light into multi-angle scattered light. This softens the illumination, allowing it to penetrate deep into the plant canopy and reach the lower leaves, thereby enabling efficient, simultaneous photosynthesis across the entire plant.
Achieving high yields in commercial plastic greenhouses is not a matter of piling up expensive heating or air-conditioning equipment; rather, it lies in the efficient, coordinated integration of ventilation, shading, and cooling systems with the dynamics of the natural environment.
- Natural convection ventilation: Fully open roof vents or staggered window openings facilitate efficient heat exhaust, while air inlets equipped with insect screens ensure continuous ventilation and cooling with minimal energy consumption, effectively blocking the entry of pests such as aphids and thrips
- External shading and cooling system: A shading screen is installed 0.5 meters above the roof ridge, reflecting and dissipating solar radiant energy before it can penetrate the covering material; empirical measurements show that the ambient temperature inside the greenhouse can be reduced by 3°C to 6°C;
- Dual-function internal thermal insulation and shading system: At night, the system closes automatically to create a double-layered insulating air cushion, which prevents heat loss from long-wave radiation emitted by the ground surface—reducing nighttime heating energy consumption by 25%–35%. During the day, the system extends fully under intense light to regulate the local temperature and humidity within the plant canopy;
- Forced evaporative cooling via negative-pressure wet-curtain ventilation: During hot, dry summer weather—even when external temperatures reach 38°C—longitudinal negative-pressure ventilation can maintain the temperature inside a greenhouse within an optimal range of 26°C to 29°C.
For multi-span plastic greenhouse, the wall thickness of structural components, resistance to wind and snow loads, and foundation depth must be determined through rigorous, customized mechanical calculations. These calculations are based on the project site’s geographic coordinates, elevation, historical extreme weather data, and the specific load requirements imposed by the crops being cultivated (including the weight of trellised plants). The Zheyang Engineering Team consistently applies a disciplined engineering approach to empower agricultural production, providing every investor with comprehensive, end-to-end support—from initial blueprint planning and material processing to on-site installation guidance.
