A recent study by the GRDC National Grain Storage Extension Team revealed that theoretical fan specifications alone are not sufficient for effective aeration. When four fans with identical 0.37 kW motors were tested under typical backpressure conditions—around 300 pascals—the real-world performance varied drastically, with airflow ranging from just 120 L/s to as much as 360 L/s. That difference can mean the success or failure of cooling grain in a 100-tonne silo.
The research showed that fan design details such as impeller shape and housing matter far more than the motor rating printed on labels. In a wheat-filled 100 t silo operating at 2 L/s per tonne, backpressure hovers just above 200 Pa, but with canola the backpressure is much higher—around 400 Pa at the same rate and close to 900 Pa if aerated at 4 L/s per tonne.
Because aeration cooling typically requires airflow between 2 and 4 L/s per tonne, growers need to demand empirical performance data that reflects real operational conditions—not just motor power. Verified fan curves that consider grain type, stack height, and expected backpressure are critical for ensuring systems perform when it counts.
What This Means for Growers
Aeration is more than a plug-and-play solution. For effective grain cooling, fans must be evaluated under realistic conditions. By insisting on tested airflow data and matching systems to the type and depth of grain stored, growers can protect grain quality and ensure aeration performs reliably.
For more, go to the full GRDC GroundCover post:
Research guides growers investing in grain storage aeration