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Tool report
Fluids & HVAC
Quick checks for Reynolds, pressure drop, and duct velocity.
DateMay 16, 2026
Inputs
Flow Q (m3/h)12 m3/h
Diameter D (mm)40 mm
Pipe length L (m)50 m
Roughness ε (mm)0.05 mm
Air flow Q (m3/h)1,800 m3/h
Target velocity v (m/s)6 m/s
Volume V (m3)150 m3
ACH (1/h)8 1/h
Results
Pipe Re106,103.2954
Pipe F0.0227
Pipe Velocity2.6526
Pipe Dp99,808.4175
Duct Area0.0833
Duct Diameter0.3257
Duct Dynamic Pressure21.6
Ach Flow M3h1,200
Ach Flow M3s0.3333
Formula
Δp = f·(L/D)·ρ·v^2/2 | Re = ρ·v·D/μ | Q = A·v
Assumptions
- Water at 20°C with ?=1000 kg/m³ and µ=1 cP assumed.
- Minor losses and fittings are not included.
References
- Crane TP-410 (Flow of Fluids)
- ASHRAE Fundamentals
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