Industrial Filtration, Separation & Dust Collection worked example

Dust Collector CFM at 99% capture and duct-balance efficiency: a worked example

Push capture and duct-balance efficiency up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use it when checking hood capture airflow, branch duct airflow, collector inlet CFM, or fan capacity for a dust collection system.

The inputs for this scenario

  • Total design dust collector airflow: 18,000 CFM (unchanged)
  • Shift operating hours basis: 8 hr (unchanged)
  • Capture and duct-balance efficiency: 99 % (raised for this scenario; the documented default is 92)

Working through the calculation

  • Applying the documented formula (Raw dust collector CFM = design dust collector airflow รท operating time basis) to the inputs above produces each figure below.
  • At this operating point the engine returns 2,228 CFM / hr for effective dust collector cfm, the number this scenario is built around.
  • At this operating point the engine returns 2,250 CFM / hr for raw dust collector cfm.
  • At this operating point the engine returns 99 % for capture and balance allowance.
  • At this operating point the engine returns 8 hr for runtime.

How this compares with the baseline

  • Against the tool's baseline example, where capture and duct-balance efficiency sits at 92% and the headline result is 2,070 CFM / hr, this scenario comes in 7.61% above the baseline at 2,228 CFM / hr.
  • It computes effective dust collector CFM by dividing design airflow over the operating-hours basis and then applying a capture-and-balance allowance. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Effective dust collector CFM: 2,228 CFM / hr (headline result)
  • Raw dust collector CFM: 2,250 CFM / hr
  • Capture and balance allowance: 99 %
  • Runtime: 8 hr

Run it with your numbers

  • Every input above is editable in the live Dust Collector CFM calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.