Inputs
Formula used
TDH = Pressure head + Static head + Friction head + Minor loss head, then apply a safety margin.
- Pressure head: (Pout − Pin) / (ρg)
- Static head: elevation difference between pump and critical outlet
- Friction head (Hazen–Williams): hf = 10.67 L Q1.852 / (C1.852 d4.871)
- Minor losses: hm = K · v² / (2g)
- Power: Phyd = ρgQH, then divide by efficiencies
Assumes water and steady flow under typical site conditions.
How to use this calculator
- Enter peak flow at the farthest, highest demand point.
- Enter inlet and required outlet pressures in kPa.
- Add elevation difference from pump centerline to outlet.
- Enter total pipe length and true internal diameter.
- Set C value and sum K for fittings and valves.
- Choose realistic efficiencies and a safety margin.
- Press calculate, then download CSV or PDF if needed.
Example data table
| Scenario | Flow (m³/h) | Pin (kPa) | Pout (kPa) | Elev (m) | L (m) | ID (mm) | C | K | Safety (%) |
|---|---|---|---|---|---|---|---|---|---|
| High-rise temporary supply | 30 | 150 | 450 | 25 | 120 | 80 | 130 | 8 | 10 |
| Campus distribution loop | 55 | 200 | 500 | 12 | 260 | 125 | 140 | 10 | 8 |
| Workshop washdown line | 12 | 180 | 380 | 6 | 90 | 63 | 120 | 6 | 12 |
Run these rows in the form to reproduce similar outputs.
Professional guide: booster pump sizing for construction
1) Why booster pumps matter onsite
Construction water demand changes daily. Temporary towers, curing stations, washdown bays, and site offices can pull flow at the same time. A correctly sized booster pump stabilizes pressure, prevents hose collapse, and keeps fixtures performing at upper floors and distant zones.
2) Define the design flow
Start with peak simultaneous demand, not average usage. Add known high users such as concrete curing, dust suppression, and pressure washing. If your site phases work areas, calculate for the worst active phase to avoid undersizing.
3) Set pressure targets at the critical point
The critical point is usually the highest elevation or farthest run with the strictest minimum pressure. Enter suction pressure at the pump inlet and required discharge pressure at that critical outlet. The difference becomes pressure head, converted into meters of water.
4) Account for elevation and routing
Static elevation is the vertical lift between the pump centerline and the outlet elevation. Pipe length should include equivalent length for route complexity. Long corridors, risers, and temporary manifolds can significantly increase losses as the site grows.
5) Estimate friction losses with practical parameters
This calculator uses the Hazen–Williams method for water. Choose a realistic internal diameter, not the nominal size. Use a C value reflecting pipe condition and material. Add minor losses by summing K for fittings, valves, strainers, and backflow devices.
6) Apply efficiency and safety margin
Hydraulic power depends on flow and head, but motor input depends on efficiencies. Use the pump efficiency at the expected operating point. Motor efficiency varies by frame and load. A safety margin helps cover uncertainty, fouling, and minor future extensions.
7) Use energy and cost for planning
Energy cost often determines whether a variable-speed system pays back. After calculating, compare daily kWh and cost across alternative pipe diameters or routing options. Even small head reductions can reduce electrical power noticeably, improving reliability and budget control.
8) Example data with typical results
Example inputs: Flow 30 m³/h, Pin 150 kPa, Pout 450 kPa, Elevation 25 m, Length 120 m, ID 80 mm, C 130, K 8, Safety 10%, Pump 70%, Motor 90%, 8 h/day, Tariff 0.20.
Expected outputs: design TDH around 63 m, electrical power about 7 kW, daily energy near 56 kWh, and daily cost close to 11 currency units. Your results will vary with diameter, fittings, and pressures.
FAQs
1) What is total dynamic head?
Total dynamic head is the combined pressure, elevation, friction, and fitting losses the pump must overcome at the design flow, typically increased by a safety margin.
2) When should I increase the safety margin?
Increase margin when the routing is uncertain, fittings will change, water quality may foul lines, or future extensions are likely. Keep it reasonable to avoid oversizing.
3) How do I choose Hazen–Williams C?
Use higher C for smooth new pipe and lower C for rough, older, or temporary lines. If unsure, use a conservative mid-range value and review sensitivity.
4) What should I include in minor loss K?
Sum K values for elbows, tees, reducers, valves, strainers, meters, backflow devices, and hose reels. For quick estimates, group fittings and validate with field measurements.
5) Does this calculator include suction lift and NPSH?
No. It focuses on discharge-side head and power. If suction conditions are challenging, check NPSH available versus required, and ensure priming and inlet sizing are adequate.
6) Can I use it for fluids other than water?
It is tuned for water. Different fluids change density, viscosity, and friction behavior. For non-water fluids, use an appropriate friction method and update density and loss coefficients.
7) How can I reduce power without changing the pump?
Increase pipe diameter, shorten runs, reduce fittings, clean strainers, and avoid excessive pressure targets. Variable-speed control can also match demand and reduce throttling losses.
Use results to select pumps and reduce surprises onsite.