Garden planning
Greenhouse Ventilation Calculator
Size exhaust airflow and a passive intake opening from greenhouse volume and planned air changes.
Add local climate context
Enter a US ZIP code for its USDA hardiness zone and location-specific planning guidance.
Your estimate will appear here
Enter your project details and calculate for a practical planning estimate.
How this estimate works
- • Greenhouse volume is length × width × average interior height.
- • The base airflow target is volume × air changes per hour ÷ 60.
- • Fan capacity is increased for the selected derating. Intake area assumes 400 feet per minute through 70% net-free-area louvers.
Before you begin
- • The calculator does not select a climate-specific air-change target or account for solar heat gain.
- • Fan curves, ducting, insect screens, shade cloth, and local code can require a larger fan or intake.
- • Natural ventilation and staged fans should be designed for the specific structure and crop.
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