Pump type selection guide
Fluids
Compare positive displacement and dynamic pumps by flow, pressure, viscosity, and service conditions.
Calculator tabs
Fluids & HVACMulti-check
Fluids & HVAC Quick Pack
Three fast checks: (1) Reynolds, friction factor, and pressure loss for water, (2) duct diameter from velocity method, (3) ACH to flow conversion. For concept sizing; use standards for detailed design.
1) Water Reynolds, f, and Pressure Drop (Darcy-Weisbach)
Re106,103
f (Darcy)0.0227
Velocity v2.65 m/s
Δp (along L)99.81 kPa
Assumptions: water at 20°C (ρ=1000 kg/m³, μ=1 cP). Δp = f·(L/D)·ρv²/2. Minor losses, fittings, and temperature effects are excluded.
2) Duct Velocity Method (equivalent diameter)
Area A833.33 dm²
Equivalent D326 mm
Dynamic pressure q22 Pa
Typical velocities: offices 4–6 m/s, industrial 6–10 m/s. Check manufacturer catalogs for noise and loss; elbows/dampers add extra losses.
3) Air Changes per Hour (ACH) ↔ Flow
Flow1,200 m³/h
Flow (m³/s)0.333 m³/s
Typical ACH: offices 4–8, classrooms 6–10, labs 8–15. Check building codes and indoor air quality standards.
Projects & Export
Save this calculation to a local project or export inputs/outputs.
Exports inputs and outputs only.
Share & Report
Create a shareable link or open a print-ready report.
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
Guides
Related guides
Browse guides with similar tags.
Similar calculators
Related calculators
Explore calculators with similar categories or tags.
Unit Converter
Free
Fast unit conversions for length, force, pressure, and energy.
Engineering Sanity Check Lab
Beta
Validate variables, units, and formulas in one screen.
Basic Heat Flow
Free
Estimate heat flow through a single layer with manual inputs.
Pipe Pressure Loss
Free
Compute Re, friction factor, and pressure loss via Darcy-Weisbach.
Other picks
These might help too
Review alternative calculators for adjacent needs.
Tensile Stress
Free
Compute tensile stress from force and cross-section area.
Bending & Deflection
Free
Bending stress and max deflection for a simply supported beam.
Compressor CC
Free
Estimate displacement from bore, stroke, and rpm.
Hydraulic Cylinder Force & Speed
Free
Compute extend/retract force and speed from pressure and flow.