Introduction A comfortable, well ventilated dairy farm is critical to thriving cows, consistent milk production, and overall success of the farm. When the temperature and humidity rise cows can become very uncomfortable and experience heat stress. Efficient air movement can allow for the removal of unwanted heat, moisture, odors and stale air from the barn while bringing in fresh air. This is why choosing the right Dairy Farm Fans has become a priority to many modern day dairy farms. Fans are not just a piece of equipment, when properly selected, installed, positioned and maintained they can add value to the comfort of your cows and the ventilation of your barn. Proper ventilation can even impact feeding behavior, resting, milk production, and overall farm performance. Modern day farms use a variety of ventilation equipment based on their facility type and size, the number of cows, climate and other factors. Dairy Barn Fans, Cow Cooling and Farm Ventilation Fans, and complete Dairy Farm Ventilation strategies offer a variety of ventilation improvements for the modern day barn. This guide will discuss the importance of proper ventilation in the dairy, the benefits of fans, types of fans, and considerations for choosing ventilation equipment for your barn. Why Ventilation is Important on a Dairy Farm Cows constantly produce body heat, moisture from breathing and other processes, and manure, urine, feed, and bedding can add to the amount of moisture and odor in the barn. If the warm, moist air is not constantly moved away from the animals area it can often lead to an uncomfortable housing environment. On milder days, natural convection through sidelights, doors, curtains, and the ridge can be enough to ventilate a barn. But on hotter days, or when natural ventilation is minimal, mechanical ventilation becomes increasingly important. The goal is to remove stale indoor air and replace it with fresh air from outside, and on hot days fans are also needed to provide adequate air movement around the animals in order to remove body heat. This can often have a significant effect on the comfort of your herd as the moving air aids in evaporative cooling. Poor ventilation can lead to a variety of issues: cows are often less willing to rest, spend less time at the feed bunk, and heat stress can occur. High humidity can increase the effect of a hot day, and make natural cooling methods such as evaporative cooling inefficient. A proper ventilation system addresses both the exchange of indoor and outdoor air, and the cooling needs of the animals. Just installing larger fans is not a solution, proper installation and building design must take into account air inlets, exhaust locations, and the internal layout of the structure. Understanding Dairy Farm Fans Dairy Farm Fans are mechanical devices that move or exhaust air from a dairy facility or farm. Based on the fan type, they can offer general circulation, heat removal, fresh air exchange, or cooling functions. What works for one barn may not work for another. Large freestall barns, small dairy facilities, holding areas, and milking parlors all have different needs. Proper fan selection is based on several factors such as airflow capacity, diameter, motor efficiency, speed, noise, maintenance needs, and installation location. The amount of energy a fan uses is also an important factor as they may be required to run for long periods of time when the weather demands. The application should always be considered when purchasing equipment. If your goal is to cool cows at a feeding area, it may require a different set up than exhausting hot air away from the building. Proper fan design focuses on achieving useful air movement at cow level rather than pushing air around the top of the structure. Moving air at animal eye level can be much more beneficial to the comfort of a cow than trying to push large amounts of air around the ceiling. The Role of Dairy Barn Fans Dairy Barn Fans are commonly used in livestock facilities for increased air movement. They are an effective way to avoid heat buildup and stale air pockets in the barn. Even if a building has great natural ventilation through sidelights, areas of the barn can often have poor airflow. Air movement throughout the building can be very uneven with some areas experiencing little airflow while others have greater movement. Fans can help balance out the air movement throughout a structure. Horizontal circulation fans are often used to move greater distances of air horizontally across the animal area. They are commonly used in barns that keep cows in a freestall or along a feed aisle for large periods of time. Exhaust fans are another popular option for removing hot, stale air from a building. They are often used in conjunction with naturally ventilated structures that require additional cooling or power to increase air exchange rates. Installation location also has a significant impact on performance. Mounting a fan too high can cause it to push air around the top of the structure when what is needed is increased movement across the animals. Incorrect fan angles can result in airflow being pushed into a non-critical area of the building Building airflow balance is an important consideration in fan installation as the fan needs to achieve proper flow rates at a specific angle in order to impact the critical areas of a building such as feeding areas, crowding zones, or the freestall rest areas. Airflow entering the building through air inlets, or natural openings should ideally move across the animal area and then exit the structure via exhaust fans, or other natural openings. Cow Cooling Fans and Heat Stress One of the most important applications of modern day ventilation is combating heat stress. Cow Cooling Fans can help by providing a cooling airflow directly over the animals. They can be especially beneficial during hot and humid conditions. Cows are often negatively impacted by high temperatures due to their natural body heat production. High producing dairy cows can often be