Industrial Minerals & Powder Processing worked example

Dust Collection Airflow Load at 11% system derating factor: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop system derating factor to 11%, then walk the calculation through step by step. Estimate the total airflow (CFM) required for a dust collection system serving mineral processing transfer points, screens, mills, conveyors, and bagging operations.

The inputs for this scenario

  • Number of active pickup points: 12 points (held at the documented default)
  • Average CFM per pickup point: 800 CFM (held at the documented default)
  • System derating factor: 11 % (the input this scenario stresses; the baseline uses 15)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross required airflow = number of active pickup points x average CFM per pickup point.
  • Total load works out to 9,600 CFM at these inputs, and this is the headline figure for the scenario.
  • Hourly equivalent works out to 873 CFM / hr at these inputs.
  • Input load works out to 12 CFM at these inputs.
  • System derating factor works out to 800 % at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where system derating factor sits at 15% and the headline result is 9,600 CFM, this scenario lands almost exactly on the baseline at 9,600 CFM.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to system derating factor, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes every pickup point runs simultaneously at the same average CFM; staggered or blast-gated hoods that never all run at once will be oversized by this method.

Results at a glance

  • Total load: 9,600 CFM (headline result)
  • Hourly equivalent: 873 CFM / hr
  • Input load: 12 CFM
  • System derating factor: 800 %

Run it with your numbers

  • To rerun this with your own numbers, open the live Dust Collection Airflow Load calculator, set system derating factor to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.