Stored-Grain Aeration Fan Airflow
The fan airflow to cool or dry stored grain.
Example
You enter
- Stored grain (bushels) 20000
- Target airflow (cfm/bu, 0.1-0.25 cool, 0.5-1.0 dry) 0.15
You get
- Required fan airflow 3000 cfm
- Cooling hours 100
Details, formula, and sources
required CFM = rate x bushels, with the ~15/rate cooling-front rule. Aeration cooling (0.1-0.25 cfm/bu) is a different job from natural-air drying (0.5-1.0). Static pressure rises steeply with depth and fan power grows ~fourfold when the rate or depth doubles, so a fan sized on cfm/bu alone stalls in a tall bin.
required_cfm = rate_cfm_per_bu x bushels; cooling_hours = 15 / rate_cfm_per_bu (per cooling front).
Stored-grain aeration fan airflow (MWPS / university extension; Shedd airflow-resistance curves), by name.
The cfm-per-bushel airflow relation and the cooling-front rule are public MWPS / extension results; the fan selection at the design static pressure governs.
Estimate. AHJ and licensed professional govern.
Field names used by the API: bin_capacity_bu, airflow_rate, required_cfm, cooling_hours
- Airflow bands aeration cooling 0.1-0.25 cfm/bu, natural-air drying 0.5-1.0 cfm/buMWPS / extension
- Static-pressure stall power grows ~fourfold when the rate or depth doubles; read the fan curve at the design static pressureShedd airflow-resistance curves