Duct Pressure Drop Calculator

Calculate total pressure drop in HVAC duct systems

Duct Parameters

Fittings

Pressure Drop Results

Total Pressure Drop
28.327 in. w.g.

Pressure Components

Straight Duct:28.1879 in. w.g.Elbow Losses:0.0889 in. w.g.Transition Losses:0.0505 in. w.g.Total Fitting Loss:0.1395 in. w.g.

Flow Properties

Velocity:1273 FPMVelocity Pressure:0.1011 in. w.g.Reynolds Number:132629Friction Factor:0.01940Loss per 100 ft:28.1879 in. w.g.

Equivalent Length Method

Fitting Equiv. Length:0.5 ftTotal Equiv. Length:100.5 ft
Recommended Fan Static Pressure
33.993 in. w.g.
Includes 20% safety margin
Design Guidelines:
• Residential: 0.08 in. w.g./100 ft typical
• Commercial: 0.1-0.2 in. w.g./100 ft
• Keep total ESP below 0.5 in. w.g.