Horse Stable Ventilation

There are several benefits of a continuous slot opening at the eaves. The slot opening provides equal distribution of fresh air down the length and on both sides of the stable, providing every stall with fresh air. The opening's position at the eave, 10 to 12 feet above the floor, allows the incoming cold air to be mixed and tempered a bit with stable air before reaching the horse. The long slot inlet is desirable during cold weather since air enters the stable through a relatively narrow opening as a thin sheet of cold, fresh air rather than as a large, drafty mass of air provided by an open window or door.

A minimum guideline for cold climates is to provide at least 1 inch of continuous-slot, permanent opening for each 10 feet of building width. For a 12-foot-wide stall, a 1-inch-wide continuous slot will supply 144 square inches, or 1 square foot, of permanent opening. One functional and recommended design, shown in Figure 7, incorporates 3 to 4 inches of permanent opening at the eave on each sidewall of a center aisle stable (36 feet wide). This is slightly above the minimum recommendation and works well to ensure a well-ventilated stable during cold and cool conditions when other stable openings are often kept closed. Some stables have larger permanent openings, sporting 13-inch eave vent openings on 16-inch eave overhangs plus a 6-inch opening at the ridge. These vents are open all year.

Other stables outfit the eave opening with a hinged panel so that the opening size may be partially closed during extreme cold weather (Figure 8). It is open the full 6 inches all summer and reduced to a 2-inch slot in the winter by swinging a 1 x 4 board over part of the opening. Do not cover more than 75 percent of the eave opening and only do so during severe weather. In foaling stalls, in moderate climates, a 2-inch by 7-foot-long slot may be installed about 20 inches above the floor to guarantee fresh air at foal level. This gets the foal off to a good start.

Figure 9. Natural ventilation construction features include high and low openings, some of which are open year-round. Larger openings provide hot weather air movement.

In addition to the permanent openings for cold weather, another set of large openings allow cooling breezes to enter the stable during warmer weather (Figure 9). Stables with interior central aisles have large endwall doors that are opened for this function. When horses are kept indoors during warm weather, allow breezes to enter the horse stall with windows or doors that open from the stall to the outside (Figure 10). Provide openings equivalent to at least 5 to 10 percent of the floor area in each stall. For a 12-foot x 12-foot box stall, sufficient openings would be a 3 x 2 1/2 foot open window for 5 percent opening or 4 x 3 1/2 foot open window (or top of Dutch door) for 10 percent opening.