A well-ventilated barn is one of the key conditions for animal health, but the line between "plenty of fresh air" and "too much draft" is often thin. Windbreak nets are built to solve exactly this problem: they let air pass through while breaking the wind before it reaches the animals. How well a net does that is described by its porosity.
Why the right balance of air and wind matters
A cow releases up to 10 liters of water into the air every day. If barn ventilation is not sufficient, this moisture accumulates together with the animals' body heat, leading to heat stress. Heat and humidity cause fertility and feeding problems in high-performance animals.
Inadequate ventilation triggers a chain of consequences: insufficient air exchange increases humidity and microbial load in the barn, this weakens the animals' natural resistance, and the result is damp bedding, dirty animals, and respiratory, skin and udder diseases. In the end, all of this reduces the herd's overall performance. A correctly chosen windbreak net, on the other hand, provides fresh air without draft, dry conditions and natural light.
What porosity actually is
A net's porosity is the ratio between the area of its openings and the net's total surface area, expressed as a percentage. The more open a net is, the higher its porosity and the more air can pass through it, but the lower its wind-breaking effect. A less open net has lower porosity but stops wind more effectively.
Alongside porosity, wind-breaking capacity matters too: it shows by how much the net reduces wind speed on the far side compared with the speed in front of it. A third indicator, the air-flow factor, shows how much net surface area you need to achieve the same airflow as a completely open opening. A denser net with lower porosity needs a considerably larger total surface area than a more open net to move the same amount of air.
Choosing a net for the purpose
PATURA offers two basic types of net, which differ precisely in porosity and therefore in intended use:
- Special net has a single cross reinforcement and porosity of around 25%, giving a wind-breaking capacity of around 60%. It suits situations where animals need a greater airflow, that is, wind protection in buildings with less demanding ventilation requirements.
- High-performance net has a double cross reinforcement and considerably lower porosity, around 10%, giving a wind-breaking capacity of around 82%. It is ideal when animals stand close to the net and when you also want good rain protection.
- Tarpaulin has no openings at all, its porosity is 0% and its wind-breaking capacity 100%, since it fully closes the opening. It is used for airtight sealing on door and ventilation systems, when the space must be closed off completely.
Choosing between them is not about which net is "better", but about which one matches your building, its exposure and the animals you are protecting from the wind.
Material and durability
PATURA windbreak nets are made of polyester coated with PVC, from flat, cross-woven threads, with every crossing point bonded so the material cannot shift. The nets are UV-stabilized, antistatic, rot-resistant, tear-resistant and non-toxic, which makes them suitable for long-term outdoor use.
Door systems and tensioning panels are tested for guaranteed resistance up to wind force 9 (up to 88 km/h), with testing extending all the way to wind force 12 (144 km/h). This means the equipment is designed with a safety margin even for exceptionally windy days, which matters especially on exposed sites.
Practical tips before you buy
Before choosing a net, take time to answer a few questions:
- How close to the net will the animals stand or lie?
- Is the building exposed to rain from one side or from several?
- Do you need occasional full closure of the opening, or just constant gentle ventilation?
- What size is the opening you want to cover, and which mounting method fits your building?
The answers determine whether a more open special net, a denser high-performance net, or a combination of net and tarpaulin on the same building makes the most sense. PATURA is the German manufacturer of these systems, and Kancler Sistem Pro is its Slovenian partner, ready to help you choose the right combination for your barn.
Need advice?
You can compare nets with different porosity levels on our windbreak netting page.