Comprehensive tools for fan performance analysis and system curve evaluation
Analyze fan performance using fan laws, system curves, and power calculations
The fan laws describe how fan performance changes with speed, diameter, and density:
Q₂/Q₁ = (N₂/N₁) × (D₂/D₁)³ (Flow)
P₂/P₁ = (N₂/N₁)² × (D₂/D₁)² × (ρ₂/ρ₁) (Pressure)
W₂/W₁ = (N₂/N₁)³ × (D₂/D₁)⁵ × (ρ₂/ρ₁) (Power)
where Q is flow rate, N is speed, D is diameter, P is pressure, W is power, and ρ is density.
The system curve represents the pressure required to move air through a duct system:
ΔP = SP + K·Q²
where ΔP is total pressure, SP is static pressure at zero flow, K is system resistance coefficient,
and Q is flow rate. The operating point is where the fan curve intersects the system curve.
Fan power requirements can be calculated as:
P = (Q × P) / (6356 × ηfan × ηmotor) (in HP)
where Q is flow in CFM, P is pressure in inches WC, and η are efficiencies as decimals.
Annual energy consumption is then:
E = P × 0.746 × Hours / (ηfan × ηmotor) (in kWh)
