Industrial Fans, Blowers & Air Movement Equipment worked example

Fan Efficiency at 66% target efficiency attainment: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target efficiency attainment to 66%, then walk the calculation through step by step. Calculate fan efficiency attainment from fans meeting efficiency target, fans tested, and the target attainment rate.

The inputs for this scenario

  • Fans meeting efficiency target: 44 fans (held at the documented default)
  • Total fans efficiency tested: 50 fans (held at the documented default)
  • Target efficiency attainment: 66 % (the input this scenario stresses; the baseline uses 92)

Working through the calculation

  • The calculation starts from the formula this tool documents: Fan efficiency attainment = fans meeting efficiency target ÷ total fans efficiency tested × 100.
  • Fan efficiency attainment works out to 88 % at these inputs, and this is the headline figure for the scenario.
  • Fan efficiency gap to target works out to -22 points at these inputs.
  • Fans meeting efficiency target works out to 44 count at these inputs.
  • Total fans efficiency tested works out to 50 count at these inputs.

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 %.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to target efficiency attainment, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It is a pass/fail count metric — it tells you how many fans met target, not by how much each one missed, so a near-miss and a gross failure count the same.

Results at a glance

  • Fan efficiency attainment: 88 % (headline result)
  • Fan efficiency gap to target: -22 points
  • Fans meeting efficiency target: 44 count
  • Total fans efficiency tested: 50 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Fan Efficiency calculator, set target efficiency attainment to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.