Rising temperatures and humidity mean producers need to assure that barn ventilation systems are doing the best job they can to keep animals as comfortable as possible this summer, says Larry Jacobson, agricultural engineer, University of Minnesota Extension.

Start by checking on these items:

  • If the barn is fully mechanically ventilated (permanently closed curtain or solid walls), make sure the barn does not have large undesigned openings, such as open walk in doors or windows. The barn needs to have sufficient static pressure so when exhaust fans are running, air inlet velocity is adequate to reach animals in pens and stalls. A static pressure target level for a barn is 1/8 in. of water gauge when all exhaust fans are operating to produce inlet air speeds of 10-plus mph, which will provide excellent barn air mixing and assist in cooling housed animals.
  • Stay ahead of heat buildup in the barn. In mechanically ventilated systems, keep the controller’s set points low enough so summer exhaust fans and sprinklers are activated early in the day. For adult animals, all the fans should be operating by the time room temperatures reach 75 degrees F or even lower. Activate cooling systems at mid-70s (indoor temperature) for large adult animals and at 80 degrees F for younger animals.
  • For naturally ventilated or curtain-sided barns, open curtains or vents early in the day. Set controllers so they are in the maximum open position by the time the temperature reaches 70 to 75 degrees F in finishing or breeding stock barns. Since outside winds drive air exchange in naturally ventilated buildings, ensure there are no large obstructions such as trees, buildings or machinery to block wind from reaching your barn’s sidewall openings.
  • Circulation fans plus sprinklers can enhance air cooling of your animals.
  • Safety of people and animals is another reason to ensure proper ventilation is being used in animal facilities, such as during manure pit pumping.

For more information on proper barn ventilation and safety, visit www.extension.umn.edu/go/1037.