Air Cleaning and Filtration Calculators

Calculators

• Air Filter Pressure Drop Calculation
  Estimate filter pressure drop at a new airflow from a rated test point, face dimensions, and loading factor.

OSRS Guides

In-depth explanations of OSRS mechanics, formulas, and planning methods.

• How to Estimate Air Filter Pressure Drop at Different Airflows
  Estimate static pressure drop across air filters at different airflow rates using square-law scaling from a known reference point. Calculate how filter loading increases resistance in HVAC and industrial filtration systems.

Frequently Asked Questions

Why use a square-law estimate?

Many airflow resistances approximately scale with flow squared over a limited range.

What is rated final resistance?

It is the manufacturer-recommended pressure loss at which a disposable filter should be replaced.

Can this compare unrelated filters?

No. Use tested curves for each exact model and size.

Why calculate face velocity?

Pressure drop and performance depend partly on airflow per face area.