Poultry Ventilation Engineering Guide
Biological air exchanges, static pressure mechanics, and tunnel cooling index calculations.
Scientific Overview
Ventilation systems maintain flock health by supplying oxygen, removing carbon dioxide, ammonia, and moisture, and managing ambient heat stress. This engineering guide details the mathematical principles of Minimum, Transitional, and Tunnel ventilation configurations.
Minimum Ventilation (Moisture Removal)
Minimum ventilation functions on timer cycles to extract excess metabolic moisture and carbon dioxide during cold weather without chilling chicks. It relies on negative pressure to draw air through wall inlets, directing cold external air upwards to mix with hot air at the ceiling before descending.
(Calculate required fan capacity using the Ventilation Fan CFM Calculator)
Ensure the air cycle time is set so that fans run for at least 60 seconds out of a 5-minute loop to maintain proper velocity and mix overhead air.
Tunnel Ventilation (Wind-Chill Cooling)
During warm weather, tunnel ventilation is activated to remove heat. Air is pulled through large cooling pads at one end of the house and exhausted by high-capacity fans at the opposite end, creating a high-velocity air stream.
The Wind-Chill Effect: Moving air increases convective heat loss, reducing the perceived temperature of feathered birds. Air velocity targets range from 2.0 m/s for broilers to 3.0 m/s for older flocks in hot climates.