Thin film greenhouse is a common type of greenhouse. Compared with glass greenhouse, PC board greenhouse, etc., the main covering material of thin film greenhouse is plastic film, which is relatively cheaper in price. The material cost of the film itself is low, and in terms of the skeleton structure requirements of the greenhouse, the film greenhouse is relatively less complex and high-strength, so the selection of skeleton materials can also save costs. For example, a film greenhouse with an area of 1000 square meters may have a construction cost that is only about one-third to one-half of that of a glass greenhouse, making it an affordable choice for some farmers with limited funds who want to engage in facility agriculture. The weight of the film is relatively light, which means that the support structure of the film greenhouse does not require a large amount of energy to maintain structural stability like other greenhouses with heavier covering materials. Moreover, the installation process of the film is relatively simple and the labor cost is also low. At the same time, during winter insulation, some simple insulation measures (such as adding insulation blankets) have relatively low costs for film greenhouses, reducing the operating costs of the greenhouse.
Sawtooth film greenhouses
Shading film greenhouses
Gothic film greenhouses
After the main skeleton structure is built, the installation speed of the film is relatively fast. Compared with glass greenhouses, film greenhouses do not have complex glass installation and sealing processes, so the overall construction cycle is shorter. A medium-sized (500-1000 square meters) thin-film greenhouse, with sufficient preparation of materials and personnel, may only take a few days to a week to complete construction and can be quickly put into production use.
Tunnel greenhouses
single span greenhouses
Venlo style greenhouse is a popular greenhouse structure, and the Venlo style greenhouse with a fully open top window has the following advantages:
1、 Good ventilation performance
Excellent natural ventilation effect: The top full window can fully utilize heat pressure and air pressure for natural ventilation. When there is sufficient sunlight during the day, the temperature inside the greenhouse rises, and the hot air rises. It is discharged outside through the top opening window, while fresh cold air from outside enters the room through the ventilation holes or gaps at the bottom of the greenhouse, forming natural convection. This natural ventilation method can effectively reduce the temperature and humidity inside the greenhouse, creating a suitable environment for plant growth. For example, during the high temperature period in summer, a well ventilated Venlo style greenhouse can control the indoor temperature to be about 3-5 ℃ lower than the outdoor temperature, reducing the damage of high temperature to plants.
Good ventilation uniformity: Due to the uniform distribution of top windows, the ventilation inside the greenhouse is more even. Compared with side windows, a full top window can avoid dead corners in ventilation and ensure that plants in various areas of the room can enjoy fresh air, which is beneficial for plant photosynthesis and respiration. In greenhouses with high planting density, the advantage of uniform ventilation is more pronounced, ensuring that every plant can grow healthily.
2、 Adequate lighting conditions
Maximum daylight: The Venlo style greenhouse features a fully open top window design that allows the greenhouse to receive maximum natural light during the day. When the window is open, it will not block sunlight, ensuring that indoor plants can fully receive sunlight. This is very important for plants that require sufficient light, such as vegetable crops like tomatoes and cucumbers, as well as various floral plants. Adequate light can promote photosynthesis in plants, increase the accumulation of photosynthetic products, and thus improve crop yield and quality. Generally speaking, Venlo style greenhouses with full top windows have a light intensity 10% -20% higher than traditional partially windowed greenhouses.
Uniform distribution of light: The top window can evenly distribute light in all corners of the greenhouse. Compared with a greenhouse with single-sided lighting, this uniform light distribution can reduce the directional differences in plant growth, making plant growth more uniform and consistent. For example, in flower cultivation, uniform lighting helps to achieve uniform color and regular shape of flowers, enhancing their ornamental and commercial value.
3、 Energy saving and efficient
Reduce ventilation energy consumption: Natural ventilation is a ventilation method that does not require additional energy consumption. The fully open top window utilizes the principle of natural ventilation, reducing reliance on mechanical ventilation equipment such as exhaust fans, thereby reducing the energy consumption of greenhouse ventilation. In a medium-sized (around 1000 square meters) Venlo style greenhouse, by fully utilizing natural ventilation, thousands of yuan in ventilation equipment operating costs can be saved annually.
Reduce heating costs: Good ventilation performance helps to timely remove excess heat from the greenhouse during the day, reducing the amount of heat required for heating at night. Moreover, on sunny days in winter, opening the top window appropriately can also regulate the temperature inside the greenhouse, using solar radiation heat to maintain a suitable indoor temperature environment, reducing the use time of heating equipment, and lowering heating costs.
4、 Easy to regulate the environment
Quickly adjust temperature and humidity: Growers can flexibly adjust the opening degree of the top window according to the environmental conditions inside and outside the greenhouse and the growth needs of plants. When the temperature and humidity are too high, all windows can be opened to quickly reduce the temperature and humidity; When the temperature is low and indoor temperature needs to be maintained, windows can be closed and heating and insulation facilities can be used to maintain indoor stability. The ability to quickly adjust the environment enables Venlo style greenhouses to adapt to the environmental requirements of different plants at different growth stages.
Optimizing carbon dioxide concentration: A well ventilated environment is conducive to the replenishment of carbon dioxide. Plants need to consume carbon dioxide during photosynthesis. A greenhouse with a fully open top window can allow fresh air (containing an appropriate amount of carbon dioxide) from the outside to enter the room through natural ventilation, avoiding the low concentration of carbon dioxide in the greenhouse and affecting plant photosynthesis. At the same time, when necessary, the indoor carbon dioxide concentration can be precisely regulated by closing some windows and using a carbon dioxide fertilization system to improve the photosynthetic efficiency of plants.
Post time: Dec-18-2024