About The Fan Static Pressure Estimator

The Fan Static Pressure Estimator combines straight duct loss, fitting loss, filter drop, coil drop, terminal loss, and a safety allowance into one design static pressure value. It helps size or compare fans during early HVAC planning.

How to Use the Fan Static Pressure Estimator Online

1. Enter duct length and the friction rate in Pa/m.
2. Add fitting, filter, coil, and terminal pressure drops in Pa.
3. Set a safety factor percentage if the design needs allowance for uncertainty.
4. Calculate and review the base and design static pressure in Pa and in.wg.

Choosing Options Correctly

Keep every pressure component in pascals before applying the safety factor. Use measured or manufacturer pressure drops when available, especially for filters, coils, and terminal devices.

Common Use Cases

• Build a quick fan pressure budget.
• Check the impact of extra filters, coils, or fittings.
• Convert design static pressure from Pa to inches of water gauge.

Quick FAQ

What does this estimate?
It estimates fan static pressure from duct, fitting, filter, coil, and terminal losses.

Does it select a fan?
No. Fan selection needs a fan curve, airflow, sound, efficiency, motor, and control review.

Why add dirty filter allowance?
Filters load over time, increasing pressure drop and required fan capability.

What should be checked after the result?
Confirm total external static pressure against equipment limits and fan performance data.