Greenhouse Fan Quantity Calculator

Sensitivity of the Greenhouse Fan Quantity result

If Rated fan airflow changes during the season, calculate a new scenario instead of adjusting fans required mentally.

Before entering required airflow

For fans required, collect Required airflow and Rated fan airflow on the Greenhouse Fan Quantity basis.

Required airflow

The Greenhouse Fan Quantity target is 7,200 CFM in the starting case.

Rated fan airflow

The Greenhouse Fan Quantity assumption is 2,400 CFM; note the source of any replacement.

A practical check for required airflow

Compare daytime and overnight conditions when required airflow can vary sharply within 24 hours.

Formula for fans required

Division connects Required airflow and Rated fan airflow in this Greenhouse Fan Quantity calculation.

The example result is 3 fans when required airflow at 7,200 CFM and rated fan airflow at 2,400 CFM.

Using the Greenhouse Fan Quantity result

The result panel emphasizes fans required. Check the input units before judging one scenario against another.

Use delivered airflow at operating static pressure. Check required airflow before applying fans required. A separate estimate of transmitted solar gain comes from Greenhouse Solar Gain Calculator.

Saving the Greenhouse Fan Quantity case

The Greenhouse Fan Quantity record should identify the scenario, Required airflow and Rated fan airflow, and Fans required.

For required airflow, note whether the entry came from a measurement, count, report, or planning assumption.

Compare the eventual field outcome with fans required on the same unit basis, keeping both values.

Greenhouse Fan Quantity low-and-high comparison

Test Greenhouse Fan Quantity with Required airflow at 7,920 CFM rather than 7,200 CFM. The displayed fans required becomes 3 fans instead of 3 fans.

The test holds rated fan airflow constant.

Test a measured range for required airflow when it may alter the decision.

Fans required questions