🎯 Why It Matters
Static pressure determines whether air can actually flow through your system. High-resistance systems (dense electronics, long ducts, filters) require high static pressure. Without sufficient pressure, airflow drops to near zero regardless of the fan's free-air CFM rating.
📐 How to Read
The fan curve plots CFM (x-axis) vs static pressure (y-axis). At zero pressure you get maximum CFM. As pressure increases, CFM decreases. The fan's maximum pressure (where CFM = 0) is called the shut-off pressure.
📏 Typical Values
Low-resistance (open chassis): 0-30 Pa. Server/electronics: 50-150 Pa. Filtered industrial: 100-300 Pa. Long ducts: 200-500 Pa. Dense battery packs: 300-800 Pa.
🔗 Related Parameters
Airflow, Fan Curve, System Resistance, Duct Design
❓ Frequently Asked Questions
How much static pressure do I need?
Calculate total system resistance: add pressure drops from filters, grills, heat sinks, and duct length. As a rule of thumb, add 50-100% safety margin to your calculation.
Axial vs centrifugal — which has higher static pressure?
Centrifugal fans produce 2-5× higher static pressure than axial fans of similar size. If your system needs >100 Pa, centrifugal is usually the better choice.
What happens if static pressure is too low?
The fan can't push air through the system. RPM stays high but airflow drops to near zero. Equipment overheats despite the fan running at full speed.