1. Pore size determines ventilation path
The pore size of black sunshade net directly affects the air flow path. When the pores are larger, air can pass through the sunshade net more smoothly, forming a larger ventilation channel. For example, for sunshade nets with pore diameters of more than 5 mm, air can be quickly exchanged inside and outside the net, which is conducive to heat dissipation and fresh air replenishment. In some large open-air planting fields, such sunshade nets can effectively reduce the stuffiness in the shed and create a relatively comfortable air environment for crop growth.
On the contrary, if the pores are smaller, the air flow path will become narrower and tortuous. For example, for sunshade nets with pore diameters of about 1 mm, air can only penetrate at a relatively slow speed, and the ventilation efficiency is significantly reduced, which is easy to cause local air stagnation, which is not conducive to the rapid discharge of heat and the uniform distribution of oxygen.
2. Impact on ventilation volume
The pore size is closely related to the ventilation volume. Shade nets with larger pores allow a larger volume of air to pass through per unit time. Taking the shade net per square meter as an example, when the pore area accounts for 30% and the pores are large, 50 cubic meters of air may pass through per minute; when the pore area accounts for only 10% and the pores are small, the amount of air passing through per minute may be less than 20 cubic meters. In the flower greenhouse, sufficient ventilation is essential for the respiration of flowers and the prevention of pests and diseases.
Shade nets with larger pores can ensure sufficient ventilation, so that flowers grow strong and reduce diseases caused by poor ventilation. In some small potted plant placement areas where ventilation requirements are not high, shade nets with smaller pores can also meet basic air exchange needs and play a certain role in wind protection.
3. Association with air permeability uniformity
Air permeability uniformity is also an important indicator for measuring the performance of black sunshade nets. Shade nets with uniform pore size can allow air to penetrate evenly into every corner of the covered area. For example, the shading net made by precision weaving technology has a very small error in the pore size, and its air permeability is uniform. Whether it is the central area or the edge area of the shading net, a relatively consistent ventilation effect can be obtained, which is conducive to the uniform growth of large-scale crops.
However, if the pore size difference is large, there will be a "dead corner" of ventilation. Some areas with small local pores are difficult for air to enter, while areas with large pores are over-ventilated, which may cause local differences in temperature and humidity, affecting the overall growth state of crops, especially in vegetable planting, which may cause uneven growth of vegetables and reduced quality.
4. Comprehensive consideration and application selection
In practical applications, it is necessary to comprehensively consider the relationship between the pore size of the black sunshade net and its ventilation and air permeability. For environments with high temperature and humidity and extremely high ventilation requirements, such as large orchards in tropical areas, a shading net with larger and uniform pores should be selected to ensure good ventilation and cooling effects. In some windy areas where the temperature and humidity control requirements are relatively low, such as some simple flower nurseries in the north, you can choose a sunshade net with smaller pores to ensure a certain amount of ventilation while playing a role in windproof and warmth.
At the same time, with the change of seasons and the different growth stages of crops, it may also be necessary to adjust the pore size of the sunshade net to adapt to different ventilation needs, thereby providing the best environmental conditions for crop growth.
