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Cooling cows efficiently with HVLS fans

Adam Hatton Published on 31 March 2014

A cool cow is a comfortable cow that eats more and produces more milk. It’s a basic philosophy common to dairy farmers, but in practice, keeping cows comfortable can be a difficult feat.

Improving air movement has been documented to effectively improve herd comfort, increase milk production and decrease the occurrence of reproductive issues and diseases. For years, dairymen relied on conventional fans for this task.



More and more dairymen are embracing an energy-saving technology – high-volume low-speed (HVLS) fans to solve typical herd comfort problems. An HVLS fan’s effectiveness lies within its immense size, not speed.

Up to 24 feet in diameter, HVLS fans use small one-horsepower or two-horsepower motors and specially engineered airfoils inspired by airplane wings. The airfoils feature winglets that create deep, steady jets of air across and around cattle, providing comfort in all areas of a facility.

The innovative design creates dramatic results. A single HVLS fan can replace up to dozens of small fans, significantly reducing energy consumption with its low-horsepower motor that costs just pennies per hour to operate. HVLS fans produce optimal breezes that make occupants feel up to 10ºF cooler, increasing productivity and comfort for cows and humans alike.

Selecting HVLS fans
An HVLS fan is an investment. Like any capital purchase, an HVLS fan offers a return on investment, and that includes more than energy savings and increased productivity. Durable, properly engineered HVLS fans feature gearboxes specifically designed to require no maintenance.

HVLS fans use high-grade parts and boast superior warranties. They are operated with easy-to-use, intuitive control systems that allow automatic scheduling so you stay focused on your cattle.


Some important factors to take into consideration when evaluating efficient cooling solutions for cows include basic dimensions of a space like square footage and ceiling height, while other details are equally valuable including the presence of obstructions and the spacing of fans.

No matter how much air your fan is moving, it will not move it through a wall, shelf or any other solid object. Although the upturned winglets available on specific models of industrial fans are designed to move air up and over solid obstructions, no fan can move air through them. This is crucial to ensure the airflow is evenly and adequately reaching all occupants of the space.

Big, slow-moving fans work differently than typical small, high-speed fans and should be spaced and sized differently as well. Understanding the airflow of the fans and the coverage areas associated with each model is important.

When evaluating an HVLS fan, make certain the company from which you are purchasing understands your space. No two spaces are alike, and no truly energy-efficient solution is a one-size-fits-all option.

It’s important to ask if the company has a dedicated department with employees and engineers who understand the unique needs of dairymen and have installed fans at numerous farms. If not, you run the risk of getting a common product when you need a tailored solution.

Recent engineering breakthroughs have created an entire line of fans to ensure there is an air-movement solution for any dairy space including milking parlors, freestall barns, calf barns, holding areas, return alleys and more.


Many HVLS fans feature variable speed controls with a wide selection of speed settings, allowing dairy producers to customize their air-movement comfort and energy costs based on the time of day and year. With traditional 48-inch to 52-inch fans, there is usually only an on/off option, but HVLS fans give dairy farmers flexibility and the ability to adjust fan operation.

Fancy features
Facilities that are frequently cleaned or that are located in particularly harsh environments can also benefit from special options available on specific HVLS fan models. A “wash-down” option was designed with nonporous, nonabsorbent and corrosion-resistant materials throughout, making it a resilient air-movement machine for such spaces.

Certain fans offer ultra-fine misting packages that produce the same cooling effect as 11 or 22 tons of air conditioning, respectively, exactly where you need and for only pennies per day. Combining air movement with the atomized mist lowers the actual temperature by up to 30ºF without getting facilities, bedding or employees wet.

Additional benefits
Beyond cooling cows, HVLS fans also improve indoor air quality, ventilation and can even be used in winter months. During those cold times, reducing the speed of HVLS fans pushes warm air trapped at ceilings down to the cattle’s level.

With their low-horsepower motors and immense coverage area, HVLS fans create incredible air movement that keeps cattle cool. Inexpensive to operate, they replace high-speed fans and offer hassle-free, year-round comfort. PD

Adam Hatton is an employee of Big Ass Fans , a designer and manufacturer of high-volume low-speed fans.