Exhaust Fan Selection Using Performance Curve Example

Referring to the available performance curves for exhaust fans, the TB71 model is identified as the appropriate choice for this duty point.

On the fan performance curve, the dynamic pressure (Pd) at the operating point is read as 50 Pa. Therefore, the static pressure (Ps) is calculated by subtracting the dynamic pressure from the total pressure:

Ps = PT – Pd = 700 – 50 = 650 Pa

From the same performance curve, the following operating parameters are determined at the intersection point corresponding to 13,000 m³/h and 700 Pa total pressure:

Impeller speed (RPM): 980 rpm

Efficiency: 75% (as read from the efficiency curve)

Sound level: 81 dB(A)

These values confirm that the TB71 fan not only meets the required airflow and pressure conditions but also operates within its optimal efficiency range at standard temperature, with acceptable noise levels for most industrial ventilation applications.