Industrial Fans, Blowers & Air Movement Equipment worked example

Fan Efficiency at 99% target efficiency attainment: a worked example

Push target efficiency attainment up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use it when checking whether fan designs, impeller selections, or production builds are meeting expected airflow and power performance.

The inputs for this scenario

  • Fans meeting efficiency target: 44 fans (unchanged)
  • Total fans efficiency tested: 50 fans (unchanged)
  • Target efficiency attainment: 99 % (raised for this scenario; the documented default is 92)

Working through the calculation

  • Applying the documented formula (Fan efficiency attainment = fans meeting efficiency target ÷ total fans efficiency tested × 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 88 % for fan efficiency attainment, the number this scenario is built around.
  • At this operating point the engine returns 11 points for fan efficiency gap to target.
  • At this operating point the engine returns 44 count for fans meeting efficiency target.
  • At this operating point the engine returns 50 count for total fans efficiency tested.

How this compares with the baseline

  • Against the tool's baseline example, where target efficiency attainment sits at 92% and the headline result is 88 %, this scenario lands almost exactly on the baseline at 88 %.
  • It computes the percentage of efficiency-tested fans that met target, then the gap in points between that attainment rate and your target attainment goal. 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

  • Fan efficiency attainment: 88 % (headline result)
  • Fan efficiency gap to target: 11 points
  • Fans meeting efficiency target: 44 count
  • Total fans efficiency tested: 50 count

Run it with your numbers

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

Last reviewed 2026-05-12.