Chilled Water Pipe Calculator 💧

Sch 40 Steel • 50°F Water • Auto updates. Shows pipe dimensions, velocity, Reynolds number, friction factor, head loss, elbow loss, and pipe + fluid weight.

Units Suggest pipe
Pipe Properties Sch 40 Steel
Inside Diameter
Inside Area
Weight (Pipe + Fluid)
Dimensions
Outside Diameter
Wall Thickness
Inside Diameter
Section Properties
Inside Area
Cross Section Area
Section Modulus
Moment of Inertia
Radius of Gyration
Weight
Weight of Pipe
Weight Pipe + Fluid
Hydraulics 50°F Water
USgpm
Velocity
Head Loss
Reynolds
Targets + weights (closest + next up/down)
Target Velocity ft/s Target Head Loss ft/100 ft
Weight Velocity % Weight Head Loss %
Max Velocity ft/s Penalty factor k
Down
Closest
Up
⚠ Velocity exceeds max limit
Fluid Properties
Fluid density
Fluid viscosity
Specific Heat
Energy factor
Flow Results
Fluid velocity
Reynolds Number
Friction factor
Head Loss
Elbow loss

Chilled Water Pipe Calculator (Sch 40 Steel) – US & Metric

This chilled water pipe calculator helps HVAC engineers and draftsmen quickly check pipe size, velocity, Reynolds number, Darcy friction factor, head loss, elbow loss, and pipe + fluid weight for Schedule 40 steel using 50°F water. Results update instantly as you change pipe size or flow.

How to use

  1. Select NPS (e.g., 3/4", 1", 2", 3"). Pipe dimensions and weight update automatically.
  2. Enter flow in USgpm or switch to Metric (L/s).
  3. Review velocity, head loss per 100 ft, and elbow loss.

Pipe size suggestion (targets)

Turn on Suggest pipe to size by your preferred design targets. Set Target Velocity and Target Head Loss, then adjust weights to prioritize lower velocity (noise/erosion control) or lower head loss (pump energy). The tool returns the closest match plus the next size down and next size up.

Weights + penalty (recommended)

Enable penalty to discourage selecting a pipe that exceeds your max velocity. When velocity goes above the limit, the score increases, pushing the recommendation toward the next larger size.

Typical chilled water design checks

CheckTypical rangeWhy it matters
Velocity4–8 ft/s (≈1.2–2.4 m/s)Controls noise, erosion, and balancing stability
Head loss2–6 ft/100 ft (≈2–6 m/100 m)Trade-off between pipe size and pump energy
Max velocity~10 ft/s (≈3.0 m/s)Use penalty to avoid overspeed selection

Disclaimer

This calculator provides engineering estimates. Always verify final sizing using project specifications, total equivalent length, fittings count, and commissioning/balancing requirements.

📚 References