Seasons and Greenhouses
Greenhouse Ventilation Rate Calculator
Planning ventilation airflow starts with consistent values for greenhouse volume and target air changes. This calculator performs that arithmetic.
Enter values for ventilation airflow
Read each Greenhouse Ventilation Rate field note before calculating ventilation airflow.
Preparing the Greenhouse Ventilation Rate values
The Greenhouse Ventilation Rate input panel defines Greenhouse volume and Target air changes. Note any Greenhouse Ventilation Rate conversion.
Greenhouse volume. Default in Greenhouse Ventilation Rate: 4,800 cu ft.
Target air changes. The Greenhouse Ventilation Rate target is 1.2 changes/min in the starting case.
Worked ventilation airflow example
Greenhouse Ventilation Rate multiplies factors from Greenhouse volume and Target air changes to produce ventilation airflow. The related Greenhouse Fan Quantity Calculator finds fans required.
Greenhouse Ventilation Rate evaluates greenhouse volume at 4,800 cu ft and target air changes at 1.2 changes/min as 5,760.00 CFM.
Using the Greenhouse Ventilation Rate result
Greenhouse Ventilation Rate summarizes its formula as Ventilation airflow.
Inlet area and fan performance at static pressure also matter. Check greenhouse volume before applying ventilation airflow. Use the Greenhouse Solar Gain tool when transmitted solar gain needs its own calculation.
Scope of this ventilation airflow calculation
Calculate airflow from greenhouse volume and air-change target. Greenhouse Ventilation Rate limits that task to Greenhouse volume and Target air changes.
Save Ventilation airflow with the Greenhouse Ventilation Rate units and scenario name.
A practical check for greenhouse volume
Compare daytime and overnight conditions when greenhouse volume can vary sharply within 24 hours.
Saving the Greenhouse Ventilation Rate case
Store the Greenhouse Ventilation Rate date, Greenhouse volume and Target air changes, and Ventilation airflow.
Separate measured greenhouse volume from an assumed value so a later user can reconstruct the case. Vapor pressure deficit also belongs in Vapor Pressure Deficit Calculator.
Add the garden outcome as a new entry, using the same units and definition as ventilation airflow.
Greenhouse volume: sensitivity example
A ten-percent test change in Greenhouse volume replaces 4,800 cu ft with 5,280 cu ft. Under the remaining sample values, ventilation airflow changes from 5,760.00 CFM to 6,336.00 CFM.
Only greenhouse volume changes in this Greenhouse Ventilation Rate example, making its numerical effect visible. Transmitted light is available from Shade Cloth Light Reduction Calculator.
Keep the original ventilation airflow and the test result as separate scenarios.
Questions about Greenhouse Ventilation Rate
How does “Inlet area and fan performance at static pressure also matter.” affect ventilation airflow?
Check it during measurement, then update greenhouse volume if the working area, period, or quantity changes.
Can Greenhouse Ventilation Rate guarantee field or greenhouse conditions?
No. The ventilation airflow value reflects the entered dates or readings. Confirm it with a current forecast or sensors positioned near the crop.