Finishing worked example

Paint Booth Airflow at 99% fan and filter efficiency: a worked example

What does the result look like when fan and filter efficiency reaches 99%? The full calculation is worked below with real intermediate numbers. Use for booth ventilation checks, filter loading discussions, and maintenance planning.

The inputs for this scenario

  • Booth opening face area: 96 ft² (unchanged)
  • Target face velocity: 100 ft / min (unchanged)
  • Fan and filter efficiency: 99 % (raised for this scenario; the documented default is 90)

Working through the calculation

  • Applying the documented formula (Effective booth airflow = booth opening area × target face velocity × fan and filter efficiency) to the inputs above produces each figure below.
  • At this operating point the engine returns 9,504 CFM for effective rate, the number this scenario is built around.
  • At this operating point the engine returns 9,600 CFM for base rate.
  • At this operating point the engine returns 96 CFM for loss to inefficiency.
  • At this operating point the engine returns 99 % for efficiency.

How this compares with the baseline

  • Against the tool's baseline example, where fan and filter efficiency sits at 90% and the headline result is 8,640 CFM, this scenario comes in 10% above the baseline at 9,504 CFM.
  • A figure at this level is achievable when fan and filter efficiency is genuinely sustained, not just peaked for a shift. It assumes uniform velocity across the opening; real booths have dead zones and edge effects, so a compliant average CFM can still leave slow spots that trap overspray.

Results at a glance

  • Effective rate: 9,504 CFM (headline result)
  • Base rate: 9,600 CFM
  • Loss to inefficiency: 96 CFM
  • Efficiency: 99 %

Run it with your numbers

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

Last reviewed 2026-05-12.