VoltCheck24 Engineering Calculator

HVAC Duct Pressure Loss and Fan Motor Calculator

Estimate duct friction loss, total static pressure, airflow velocity, and fan motor power for HVAC and cleanroom ventilation systems.

Open Interactive Calculator Open Cleanroom Differential Pressure Calculator

How to use this calculator

  1. Collect the values below from the equipment nameplate, data sheet, or field measurement.
  2. Enter values using one consistent unit system and use worst-case operating conditions.
  3. Review the result, margin, and engineering note before selecting hardware.
  4. Cross-check the result with the related calculator and save the review for your project record.

Input checklist

Example field question

Use this calculator when a design review or site issue requires a quick engineering check before a detailed manufacturer selection.

Common mistakes to avoid

Do not mix nominal values with measured worst-case values. Keep units consistent and include cable, temperature, duty, and derating assumptions where applicable.

Standards and validation

Review the result against local codes, IEC/NEC/NFPA/ISO practices when applicable, project specifications, and the latest manufacturer data sheet.

Recommended workflow

Start with the primary calculation, then use the related tool to check the next design dependency. Save or print the result only after the assumptions and worst-case conditions are confirmed.

Start with the primary inputsCheck the related dependency

Formula and Inputs

Total pressure loss combines straight-duct friction, fittings, filters, coils, dampers, and terminal-device losses.

Industrial Use Cases

Use this page for factory ventilation, cleanrooms, exhaust systems, process air, and industrial supply-air design.

Engineering Note

Use certified fan curves at the actual airflow and static pressure. Check filter loading, leakage class, noise, temperature, and fire-damper requirements.

FAQ

Why does a dirty filter change fan selection?

Filter pressure drop rises as the filter loads, so the design point must include a clean-to-dirty operating range.

Should I use nominal or actual airflow?

Use the required operating airflow at the design temperature and pressure condition.

Preliminary engineering reference only. Confirm final selections against current standards, project specifications, and manufacturer data.