What is the best place to mount a circulation fan in a dairy barn?

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A dairy barn with black and white cows eating hay, equipped with red ventilation fans on the ceiling

To determine the best place for your fans in a dairy barn you have to consider several aspects. As every barn is built differently, customization is the key to reach an optimal result. We have included a few guidelines for you below:


  • Provide a refreshing airflow over the cubicles. This is where the cows spent the largest amount of time.  Save at least 1.5 meters of free space on the suction side of the fan for optimal efficiency.
  • Make use of existing trusses to mount 130-centimeter basket fans with a chain or to install smaller basket fans directly.
  • Mount a 130 cm basket fan between double cubicles. The reach of the fan is wide enough to provide both cubicles with a cooling effect.
  • Mount the fans by extension of each other
  • Use spaces that do not need to be ventilated (Such as the area for calves) for the suction side of the fan. 


  • Don’t mount fans in places that the cows can reach. For a fan with a coarse-mesh grill, the minimal required height to mount the fan is 2.7 meters measuring from the bottom of the fan to the ground.
  • Don’t hang fans above the feeding racks. In practice, we see that this dries out the food, which can result in cows solely consuming the concentrate feed. This can in turn cause ruminal acidification. An additional disadvantage is that the cows are more likely to lay down on the manure grid in the cool air stream, increasing the risk of udder infections.
  • Make sure there are as little obstacles to the air stream as possible for the most effective and efficient use of fans. Take care of subtle obstacles such as feed robots for example. 

What fan size do you require?

In order to determine where to place the fans, It is good to know that this differs depending on the size of the fan. Big fans are often more efficient and generally move more air than smaller fans. With one 130cm Basket fan, you can provide a fresh breeze wide enough for a double cubicle. Because the fans come with a coarse-mesh grill, keeping the air resistance to a minimum, the minimal required height to mount the fan is 2.7 meters measuring from the bottom of the fan to the ground. In case the barn is lower than the previously mentioned height, we of course recommend using a smaller basket fan. These fans come with a fine-mesh grill that ensure they can be safely mounted in places under 2.7m. Do pay attention that you mount the fans outside of the reach of the cattle and that you will require a larger number of fans to create the desired effect.

What is the ideal tilt angle?

The tilt angle depends on the type and the diameter of the fan. For our most commonly sold 130cm basket fan, we recommend a tilt angle of around 20 degrees. This angle ensures an optimal spread of the airstream across the reach of around 15 meters long and 7 meters wide.

Other locations in the barn

After seeing positive results near the cubicles, dairy farmers often decide to employ fans in the waiting or milking areas of the barn as well. In these areas, there is often less space for a large fan. We recommend using a smaller basket fan or a horizontal circulation fan with a casing here. The advantage of a fan with a casing is the more directional air stream with which the air speed remains high over a longer distance. This can be favorable when deciding on the ideal place of installation.

Looking for more information? Read the full article in our white paper

Are you looking for more information on this topic? You can find more information in our white paper covering topics such as how many fans you need in your dairy barn, what the ideal tilt angle is and which size will work best for your building. For more information, please visit our topic page on heat stress in dairy cows here..

An open brochure with a cover featuring a dairy barn and text about creating an optimal climate in a dairy barn


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published on July 23, 2020

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