importance of ventilation in horse stalls
Q: I’m in the process of planning a barn in Missouri, and finances require an economical metal post-and-frame structure. I’ve studied Blackburn’s ventilation and lighting philosophies and will incorporate them as best I can.
My question is about orienting the barn. I plan to have a center aisle, with exterior Dutch doors in every stall. Each 12’x12’ stall will have an exit to the main 12’ aisle as well as to an outside run-in. The stalls will be used primarily during more extreme weather or when I need to confine a horse due to injury or illness, otherwise the horses will be outside. Overhangs on both sides of the barn will function as run-in shelters for the paddocks.
I know from your writings that the ideal orientation is perpendicular to the prevailing summer breeze. However, because Missouri’s cold winter winds are from the same direction, the horses on that side of the barn won’t have wind protection when in the run-in areas. I know that’s less of a problem for owners who keep their horses in stalls most of the time, so I’ve not been able to find an answer to this question. I will obviously allow them access to the stalls during the bitter cold weather we get, but for most of the winter all they need is some windbreak. How do I optimize winter protection without compromising ventilation?
Worried about Winter
A: Orientation is certainly very important when siting your barn. But because wind is always changing and its direction and velocity can be affected by terrain, other structures, and vegetation, the angle is not a hard and fast rule. It’s good to try and locate the barn perpendicular to the prevailing summer breeze but that also depends on the design of your barn. If you have lived on the farm a few years you may know the particular wind patterns for your property.
The design of the barn is as critical – if not more so – than the orientation. How and where you permit air to enter the barn (preferably along the low wall along the long side of the barn and at the eaves where the roof joins the side walls), and where it is allowed to exhaust are critical. In some areas, it may be necessary to provide some form of close-able dampers on the low wall vents to control the wind and temperature that can impact a horse that is in the stall but doesn’t have the flexibility to get away from it.
The environment within the barn should be within 8 to 10 degrees of the temperature on the outside. Your barn should ventilate vertically to reduce the horizontal movement of bacterial- and moisture-laden air.
We always say the best environment for the horse is outdoors where it can make its own choices about its environment and health. A naturally-kept horse should be able to get out of the hot sun and find shade or get out of a cold wind in a shelter or behind a wind block.
By turning your horses out most of the time you are certainly on the right track for happy, healthy animals.
Missouri’s winter weather isn’t so extreme that it prevents you from a center aisle barn with stalls on both sides. Orient your barn so that turnouts are on the windward side of the barn and leave the Dutch doors open so your horses can get inside away from the wind. For the turnouts on the cold windward side of the barn, blanket the horses. And keep their winter coats unclipped.
Since you’ve read “Healthy Stables by Design,” you know that Blackburn designs typically use the chimney effect and the Bernoulli principle to create natural ventilation. Our barns become passively designed machines that work to provide healthy conditions for the horses inside.
Good luck with your new barn!
We recently wrote about muck pits and dealing with manure at horse facilities and received comments about stabling time; some saying that shorter times in stalls are better for horses. We completely agree. The longer a horse is stabled indoors, the more likely it is that the animal will be standing in urine-soaked bedding for at least part of the day. And we all know ammonia causes problems.
We want the air inside our barns to be as clean as the air outside the barn. Blackburn Architects’ designs stress aerodynamic ventilation, strategic natural light, and passive solar heating and cooling in our equestrian facilities.
When John Blackburn was beginning to design horse facilities more than 30 years ago, he found combining regionally-appropriate architectural elements with aerodynamic airflow principles created pleasing, healthy spaces for equines and their caregivers. Even early on in his career, heading into his barns was refreshing. “In August,” he has said, “in the dead of summer, when there was no wind – your hair would lift” from the natural ventilation created by the proper placement of the barn on a site, and the use of two engineering principles, which Blackburn Architects has employed in every design then and since:
1. The Bernoulli Principle – As air blows across a surface, e.g. a bird’s wing, it creates lift. Barn placement on a site is critical. If possible, a barn should capture the prevailing summer breezes (for horses you’re always more concerned with cooling rather than warming).
Inside the barn, air needs to move up and out. Blackburn frequently specifies ridge line vents in our designs. The vertical ventilation rids the barn of odors, pathogens and infectious bacteria that could otherwise be transported from horse to horse.
Even in cold climates like Montana, Blackburn Architects designs for maximum ventilation in the winter. “A horse gives off a tremendous amount of humidity; a lot of bacteria and in a contained area – like a stall – that’s an incubator for disease. I don’t care how cold it is where you live, you want to ventilate your barn year-round,” explained John Blackburn.
2. The Chimney Effect – Maximizing natural light in a barn creates a healthy environment by helping to “sterilize” the spaces. For example, as the sun moves across the sky and a band of light travels through a stall – perhaps through the upper portion of an exterior Dutch door left open – it helps to dry and evaporate urine. Blackburn Architects’ spaces have a lot of windows, and skylights. Vented skylights glazed with a translucent polycarbonate panel running the length of the barn are hallmarks of our barns. The light source provides a low cost, shatter-proof feature that diffuses the light, thus eliminating harsh shadows, which could cause horses to spook. “My barns are designed to function throughout the day without the use of artificial lighting, except in enclosed rooms such as bathroom/laundry,” John Blackburn explained.
“A horse is designed to live outside in the wild. If it wants to get out of the sun, it’ll run under a tree. If it wants to get out of the wind, it’ll run behind a hill. This natural, healthy way of living is what we strive to create with our barns so that our athletic partners have the best chance of long, healthy lives – indoors or out.”
If you want to learn more, Penn State Extension has a very informative article: https://extension.psu.edu/horse-stable-ventilation.