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Ventilation Modeling of a Hen House with Outdoor Access
Hojae Yi1, Eileen Fabian-Wheeler1, Michael Lee Hile1
1Agricultural and Biological Engineering Department, The Pennsylvania State University, University Park, PA 16802, USA.
Animals : an Open Access Journal From MDPI
|August 14, 2025
Summary
Optimizing ventilation in cage-free hen houses with outdoor access is crucial for hen welfare and production. Computational fluid dynamics (CFD) models show plenum ventilation and positive pressure systems improve airflow and mitigate disruptions.
Area of Science:
- Agricultural Engineering
- Animal Science
- Environmental Science
Background:
- Cage-free housing with outdoor access is increasing for hen welfare.
- Outdoor access points (pop holes) can disrupt indoor ventilation and hen behavior.
- Optimized ventilation is needed for precision flock management in cage-free systems.
Purpose of the Study:
- To develop and validate computational fluid dynamics (CFD) models for cage-free hen houses with outdoor access.
- To evaluate the impact of different ventilation strategies on indoor environmental conditions.
- To identify ventilation solutions that balance hen welfare, environmental control, and production.
Main Methods:
- Developed and validated CFD models simulating a cage-free hen house with specific components (fans, inlets, pens, outdoor access).
- Simulated four distinct ventilation scenarios under real-world conditions.
- Compared CFD predictions of airflow velocity and temperature against measured data.
Main Results:
- CFD models predicted airflow velocity with <50% error for three scenarios and temperature with <6% error for all scenarios.
- Plenum-based ventilation systems achieved significantly higher air changes per hour compared to sidewall systems.
- Positive pressure ventilation effectively reduced negative impacts on outdoor access.
Conclusions:
- Validated CFD models provide a reliable tool for optimizing ventilation in cage-free hen houses.
- Plenum ventilation and positive pressure systems are recommended for improved environmental control and hen welfare.
- These findings support cost-effective improvements in hen welfare for the egg industry.
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