Air quality and barn temperature are two of the most critical environmental components that affect pig health and performance. Poor ventilation increases disease and reduces growth rate by creating a barn environment high in humidity and excess gases. An understanding of some fundamental ventilation concepts will help set up a barn environment that optimizes pig health and performance.
Minimum ventilation
Minimum ventilation is the amount of fresh air needed to be brought into the barn to control humidity and gas contaminants. In most barns, the fans assigned to minimum ventilation are variable speed fans which have two important settings – minimum speed and bandwidth.
Minimum speed is a controller setting that signifies the speed at which the minimum ventilation fans will operate at any time room temperature is below set point. When the room temperature rises above set point, minimum ventilation fans steadily increase speed until the maximum speed is achieved.
The number of degrees for variable speed fans to go from the minimum speed setting to 100% is called bandwidth. Bandwidths can be widened or narrowed based on ambient temperatures, number of fans, pig size, motor curves, or other factors that impact pig comfort.