Ten dollars per cow per month- that is what most dairy farmers spend to keep their cows cool during summer. On top of that, there are initial purchase expenses and ongoing maintenance costs. But what if nature could handle that job for free? While everyone is rushing toward mechanical systems, there are still places where natural ventilation can cool dairy buildings just as effectively.
Fabric dairy buildings are a great example of this approach. Instead of relying on constantly running ventilation fans, these structures use natural processes. Fresh air flows in from the sidewalls, rises naturally as it warms up within the building, and exits through ridge openings in the roof. To maximize effectiveness, a general rule of thumb is to include a ridge opening of 1-1.5 inches for every 10 feet of barn width. The roof pitch also plays a critical role in natural ventilation. A steeper pitch, typically 6:12 instead of the standard 4:12, improves the chimney effect by enhancing airflow. Dual eaves further contribute by offering flexibility, allowing farmers to adjust airflow based on changing weather conditions and seasonal needs.
Ridge openings are strategically placed 8-12 feet from each end of the barn to minimize downdrafts. This design also provides a sheltered area for automated milking systems, keeping them protected from rainfall and other weather conditions. Even frost that forms in the ridge openings during cold weather plays a role, as it naturally reduces airflow, helping to maintain a more comfortable environment for the cows. It is like having smart climate control powered entirely by physics rather than electricity.
One of the most noticeable features of fabric dairy buildings is how quiet they are compared to mechanically ventilated barns. Without the constant hum of high-capacity ventilation fans, the environment feels calmer. The high ceilings and abundant natural light create a bright, open atmosphere that feels more like a greenhouse than a traditional barn. While circulation fans are still used, their purpose is to maintain even temperature distribution, particularly in the areas where cows rest.
Another challenge is that the bright and quiet nature of fabric buildings tends to attract more birds than traditional designs. The high ceilings and open framework provide areas where birds can nest, making it difficult to keep the equipment below clean. This issue becomes particularly concerning considering growing awareness about avian influenza. To address these risks, farmers may need to install protective netting systems to deter birds and protect their equipment and cows.
Despite these drawbacks, the benefits of naturally ventilated fabric buildings are substantial when they are located in open areas free from wind shadows. In the long term, adopting naturally ventilated fabric buildings can provide farmers with a practical and cost-effective solution. Not only do these buildings create a more comfortable environment for cows, but they also promote operational savings by reducing dependency on mechanical ventilation systems. This approach reminds us that sustainable solutions are not always about incorporating the latest technology- they can also be about utilizing what nature already provides. For farmers looking to combine functionality with sustainability, fabric buildings present a promising option for the future of dairy farming.
Nesli Akdeniz is Asst. Professor and Extension Specialist of Controlled Environments in Livestock Production Biological Systems Engineering University of Wisconsin-Madison
