Proper ventilation in dairy barns is critical to maintaining a healthy and productive herd. Heat and moisture buildup can lead to heat stress, reduced feed intake, decreased milk production, and increased disease risk. By managing air quality with effective ventilation, dairy producers can improve cow comfort, promote animal welfare, and support long-term profitability.

Why Ventilation Matters

Cows are sensitive to heat and humidity. When barn temperatures rise above 72°F (22°C) and humidity is high, cows can suffer from heat stress, resulting in:

• Reduced dry matter intake and milk production
• Lower pregnancy rates
• Increased lameness and disease incidence
• Delayed growth and reduced future milk production in heifer calves

Moisture buildup also creates slippery floors, damp bedding, and higher bacterial loads, increasing the risk of mastitis and respiratory issues. Proper ventilation removes heat, reduces humidity, and ensures a comfortable environment for animals and staff.

Types of Ventilation Systems

According to the University of Wisconsin–Madison, there are three primary types of ventilation systems used in dairy barns:

1. Natural Ventilation – Relies on wind and temperature differences to create airflow.
2. Mechanical Ventilation – Uses fans to actively control airflow and remove heat and moisture.
3. Combination Systems – Use natural ventilation during cooler weather and mechanical systems when additional airflow is needed, such as in summer months.

Tunnel and cross ventilation are common mechanical strategies. Tunnel ventilation pushes air the length of the barn, while cross ventilation moves air parallel to stalls, creating a “cross” airflow.

Types of Fans and Their Benefits

Inlet fans inject fresh air into the dairy barn where it’s redistributed at the animal level. Circulation fans move air within the barn to equalize temperature and humidity. Exhaust fans pull fresh air from outside, maintaining consistent air quality.

Fan construction also affects performance:

• Belt-driven fans: More efficient but require periodic belt maintenance.
• Direct-drive fans: Less maintenance, lower efficiency.
• Variable-speed fans: Improve energy efficiency, reduce noise, and allow precise control over airflow.

Regular maintenance is essential: even a thin layer of dust can reduce fan efficiency by 10-40%. Inspect for cracks, worn belts, loose bolts, and lubricate pivot points to keep fans operating at peak performance.

Ventilation Efficiency and Air Exchanges

Air exchanges measure how often the air inside a barn is replaced with fresh air. Midwest Plan Service guidelines recommend:

• Winter: ~4 air changes per hour (entire barn air replaced every 15 minutes)
• Summer: 40-60 air changes per hour to prevent heat stress

Ventilation Efficiency Ratio (VER) compares the volume of air moved to the energy consumed. Fans with higher VERs reduce electricity costs and greenhouse gas emissions. Maintaining low static pressure (ideally <0.15 inches H2O) is crucial, as high static pressure decreases airflow and efficiency.

Choosing Durable Fans for Long-Term Performance

Fan housings should be metal, fiberglass, or durable plastic to resist moisture and corrosive gases common in livestock buildings. Features such as shutters prevent backflow in winter, and guards protect staff from moving parts. Choosing fans with a high VER ensures energy efficiency and reduced environmental impact. Requesting field-testing experience and longevity performance in rough environments is not out of the norm. Examples of VES-Artex testing include use in extreme weather conditions, over-using the fan, measuring motor heat tolerance when over-amping the fan, tolerance of pressure washers, and fan performance with and without accessories.

How VES-Artex Helps

VES-Artex offers a complete line of dairy barn ventilation solutions to help farmers remove heat and moisture efficiently:

• Dairy barn and freestall fans – Maximize airflow for cow comfort
• Exhaust and circulation fans – Improve air quality and reduce humidity
• Tunnel and cross ventilation systems – Create consistent airflow throughout the barn
• Variable-speed and modular systems – Tailor airflow to barn layout, herd size, and seasonal conditions

All VES-Artex fans are designed for durability, low maintenance, and high performance, helping farmers meet ventilation goals while reducing energy costs.

To ensure optimal ventilation in your dairy barns:

1. Consider barn size, herd type, season, and environmental conditions. Collaborating with a ventilation expert is certainly an option.
2. Properly install air inlets to minimize static pressure
3. Keep fans clean and well-maintained
4. Choose fans with high VER ratings and durable construction

With proper ventilation, your herd will stay healthy, comfortable, and productive year-round. VES-Artex ventilation solutions help remove heat and moisture efficiently while ensuring long-term performance and energy savings year-round. Contact your local dealer or Rep to receive a free site audit.