Air Speed Distribution in Tunnel-Ventilated Houses - Part 2

Tip Category: 
Air speed
Tunnel ventilation

As discussed in Part 1 (Volume 16 Number 4) air speed uniformity and therefore cooling is significantly affected by the smoothness of the side walls in a tunnel-ventilated house. Side wall posts or exposed studs can discourage air from moving along the side wall leading to a variation in air speed between the center and the side wall of a house of 30% or more. Since the relationship between air speed and cooling produced is exponential in nature, a 30% difference in air speed can result in 60% less cooling for the birds near the side walls of a house versus those toward the center of a house. In contrast, air velocity variation in houses with smooth side walls has been shown to be often less than 10%, resulting in significantly more uniform bird cooling than experienced in houses with rough side walls.