Flexible Duct Pressure Loss

Calculate pressure drop in flexible duct accounting for compression ratio and friction characteristics.

Flex duct nominal diameter
inches
Volumetric flow rate
CFM
Total flex duct length
feet
Fully extended: 1.0, Typical: 0.85, Compressed: 0.70

Results

Air Velocity-FPM
Friction Loss Rate-in wc/100 ft
Total Pressure Loss-in wc
References: ASHRAE Fundamentals Ch. 21 - Duct Design, ADC Flexible Duct Performance & Installation Standards