The poultry house ventilation calculator determines required airflow in CFM (cubic feet per minute) for broiler, layer, and turkey houses. Proper ventilation controls temperature, removes ammonia and moisture, and maintains bird health. Under-ventilation in summer causes heat stress and mortality; over-ventilation in winter wastes energy and chills birds.
Poultry Ventilation Calculator
How to Calculate Poultry House Ventilation
Ventilation is the single most important environmental control system in a poultry house. This poultry house ventilation calculator determines peak airflow requirements for tunnel ventilation and minimum ventilation needs for cold weather, based on bird type, count, and building size.
Peak vs. Minimum Ventilation
Peak ventilation for hot weather (tunnel ventilation) is sized to maintain house temperature within 5°F of outside temperature during maximum heat. Minimum ventilation removes moisture and ammonia in cold weather while minimizing heating costs. The ratio between peak and minimum is typically 8:1 to 10:1 — minimum ventilation fans are small-diameter fans that run continuously.
Air Velocity for Tunnel Ventilation
Effective tunnel ventilation requires 400–600 ft/min air velocity through the house cross-section. This wind speed creates a wind-chill effect that can lower the perceived temperature by 10–15°F at the bird level. To calculate air velocity: total CFM ÷ house cross-section area (width × height). Houses wider than 50 ft may need cross-ventilation or side-wall fans to achieve adequate velocity.
Frequently Asked Questions
Is this poultry ventilation calculator free?
Yes, completely free. All calculations run locally in your browser.
What is the minimum ventilation rate for broilers?
Minimum ventilation for broilers is approximately 0.1–0.15 CFM per pound of live weight in cold weather, increasing to 1.0+ CFM/lb in hot weather. A house of 25,000 broilers at 5 lbs average weight needs 125,000 lbs × 0.12 = 15,000 CFM minimum ventilation.
How do I calculate CFM for a poultry house?
Peak CFM = house volume ÷ desired air exchange time. For a 40 ft × 500 ft house at 8 ft height: 160,000 cu ft ÷ 1 minute = 160,000 CFM for 1-minute exchanges. Broilers in summer need 1–1.5 air exchanges per minute for temperature control.
What size fans are used in poultry houses?
Tunnel ventilation systems use 36-inch or 48-inch belt-drive fans rated at 11,000–14,000 CFM each. Minimum ventilation fans are smaller 16–18 inch fans at 2,000–4,000 CFM. A 40x500 house typically uses 8–12 tunnel fans plus 8–10 minimum ventilation fans.
What is tunnel ventilation in poultry houses?
Tunnel ventilation pulls air through the length of the building from inlet curtains at one end to fans at the other end. It creates high air velocity (400–500 ft/min) for a wind-chill cooling effect. It is the most effective hot weather ventilation strategy for broilers.