Summer heat waves pose a major threat to modern poultry farms. Birds lack sweat glands and rely heavily on evaporative cooling through panting. When temperatures rise above their comfort zone, feed intake drops, egg production plummets, and mortality risks rise sharply.
To combat heat stress, relying on fans alone is often not enough. The most effective solution is a synergy: combining heavy-duty exhaust fans with evaporative cooling pads in a tunnel ventilation setup.
 |  |  |
How the Synergy Works: The Negative Pressure Principle
The system operates on a simple yet highly efficient physics principle: negative pressure ventilation.
Creating a Vacuum: Heavy-duty exhaust fans installed at one end of the poultry house pull large volumes of air out, creating a slight negative pressure (vacuum) inside the building.
Forcing Air Through Wet Pads: This pressure difference forces fresh outdoor air to enter through wet cellulose cooling pads installed at the opposite end or side walls.
Evaporative Cooling: As dry, hot air passes through the water-saturated pads, moisture evaporates, absorbing heat from the air. The air temperature drops significantly before entering the living space of the birds.
Key Benefits of the Fan & Pad Combo
Temperature Drop of 5°C to 10°C: Depending on outdoor relative humidity, an optimized fan-and-pad system can reduce house temperatures by up to 10°C, keeping the flock within their thermal comfort zone (18°C–24°C).
The Wind-Chill Effect: High air velocity generated by the exhaust fans (typically 2.0 to 3.0 m/s at bird level) creates a wind-chill effect. This lowers the birds' perceived body temperature even further than what the thermometer displays.
Continuous Air Exchange: While cooling the air, the constant airflow swiftly removes harmful ammonia, carbon dioxide, dust, and excess moisture, ensuring clean air throughout the house.
Best Practices for Maximum Efficiency
To get the most out of your system, pay attention to these operational details:
Pad Maintenance: Keep pads clean and free of algae or mineral buildup to ensure unrestricted airflow.
House Tightness: Seal leaks in the building walls and roof. Air entering through cracks bypasses the cooling pads, reducing overall cooling efficiency.
Controlled Water Flow: Adjust water pumps to keep pads evenly damp without over-saturating them, preventing excessive indoor humidity.
Conclusion:
Investing in a well-calibrated exhaust fan and cooling pad system is not just an equipment upgrade—it is an insurance policy for your flock’s productivity. By mastering tunnel ventilation, you can protect your birds from summer heat stress and maintain high egg yields year-round.