This standard specifies the design, construction, material, and performance requirements for centrifugal fans used in HVAC and industrial applications. It sets the baseline for aerodynamic testing, dynamic balancing, and acoustic limits to ensure efficient and reliable ventilation.
Specifies requirements for the design, construction, performance, and testing of centrifugal fans.
Quick Reference Values
air volume tolerance± 5%
static pressure tolerance± 5%
typical dynamic balancing gradeG 6.3
recommended motor margin below 10kW15%
recommended motor margin above 10kW10%
Key Formulas
Q1/Q2 = N1/N2 — Fan Law for flow rate vs speed
P1/P2 = (N1/N2)² — Fan Law for pressure vs speed
kW1/kW2 = (N1/N2)³ — Fan Law for power vs speed
η = (Q × ΔP) / P_motor — Fan Efficiency
Practical Notes
Fan performance curves must be derated for altitude and temperature, as standard data is based on standard air density (1.2 kg/m³).
Always specify the fan discharge arrangement and rotation direction as per the standard nomenclature (e.g., CW 90, CCW 360) to avoid installation clashes.
Dynamic balancing of the impeller is critical; ensure the manufacturer provides a balancing certificate to Grade G 6.3 or better to minimize vibrations.