Tunnel Inlet Opening and Air Movement

The biggest difference between a tunnel-ventilated and a naturally ventilated house with circulation fans is the amount and uniformity of air movement. If properly designed and operated the air in a tunnel-ventilated house is exchanged about once every minute and birds throughout the house are exposed to a windchill effect of 10 degrees or more. But, if there are not enough fans or fan performance is reduced for one reason or another, the birds in a tunnel-ventilated house may not perform any be...tter than those in a naturally-ventilated house.