Static Pressure Is a System Requirement, Not an Airflow Value
The Selection Logic
When pressure is missing, the selection path matters.
Pressure Unknown Does Not Mean the Review Must Stop
Available system information can identify the major resistance sources and show what still needs to be calculated, measured or confirmed.
Same Airflow. Different System.
The pressure requirement depends on what the air must pass through. This is why airflow alone cannot define the final fan.
| Application | Airflow May Already Be Known | Pressure Mainly Depends On | Selection Direction |
|---|---|---|---|
| Workshop Ventilation | Room volume or air-change target | Duct route, louvers, outlet and system layout | Axial or centrifugal fan depending on resistance |
| Dust Collection | Capture hood or process demand | Duct, cyclone, filter and loaded collector resistance | Centrifugal / dust-collection fan |
| Chemical Exhaust | Capture or process ventilation requirement | Duct, scrubber, packed tower and discharge resistance | Corrosion-resistant fan after material review |
| Boiler / Forced Draft | Combustion-air requirement | Burner, damper, air preheater and duct resistance | Forced-draft / higher-pressure centrifugal fan |
| Pneumatic Conveying | Required conveying airflow | Pipeline geometry, material loading and conveying resistance | High-pressure centrifugal fan after system review |
Start the Inquiry Before Every Parameter Is Available
Static pressure may remain marked as "unknown" during the first review, but it must be established before the final operating point and fan model are confirmed.
Continue the Technical Review
Organize airflow, pressure, medium, temperature, layout and electrical data. Static Pressure vs Total Pressure →
Confirm which pressure value is used in the project or fan performance curve. How to Read a Fan Performance Curve →
Check airflow and pressure at the same operating point. Industrial Fan Airflow and Pressure →
Understand how airflow demand and system pressure work together. Industrial Fan Power Calculation →
Review shaft power and motor power after the duty point is established.
Fan Selection When Static Pressure Is Unknown
Can I select an industrial fan if I only know the airflow?
Not reliably. Airflow defines how much air must move, while pressure defines how much system resistance the fan must overcome. Both are required for the final operating point.
Can static pressure be reviewed from duct information?
Duct size, length, elbows, branches and process equipment can identify the main resistance sources. Final pressure should be based on a system calculation, project design value or reliable measurement.
Can motor power determine the required fan pressure?
No. Motor rating is influenced by airflow, pressure, fan efficiency, speed, drive configuration and design margin.
What should I send if no pressure calculation exists?
Send airflow, duct dimensions, approximate route, elbows, filters or collectors, process equipment, temperature, medium, site photos and any existing fan information.
Can an old fan nameplate help?
Yes. Model, airflow, pressure, RPM, motor power and nameplate information can provide useful reference data, especially for replacement projects.
Know the Airflow but Not the Static Pressure?
Send the information you already have. QIYUE FAN can review the system data and identify what must still be confirmed before final fan selection.