Mechanical
LTHW Pump Head Calculator
Estimate heating pump head from pipe length, fittings allowance, pressure drop and terminal losses.
Use this calculator for preliminary pump head checks where flow rate, index pipe length, indicative pipe pressure drop and terminal or equipment losses are known. It is intended for early-stage heating system sizing and pump duty estimates rather than final pump selection.
Inputs
Typical heating design values are often in the order of 100–300 Pa/m, depending on system type, pipe material and design objectives.
Result
Method
Total equivalent length is estimated by applying a fittings allowance to the straight pipe length:
Pipe friction loss is then estimated from equivalent length and pipe pressure drop:
Total pressure loss is taken as pipe friction loss plus terminal or equipment allowance:
Pump head is then estimated from:
- Lₑ = equivalent pipe length (m)
- L = straight pipe length (m)
- F = fittings allowance (%)
- R = pipe pressure drop (Pa/m)
- ΔPₚ = pipe friction loss (Pa)
- ΔPₑ = terminal / equipment allowance (Pa)
- ΔPₜ = total pressure loss (Pa)
- H = pump head (m)
- Calculated result = -
Reference
- This calculator estimates pump head using an assumed pipe pressure drop per metre together with allowances for fittings and terminal losses.
- Indicative heating pipe pressure drops are commonly used during early-stage design to estimate hydraulic resistance before full detailed loss calculations are undertaken.
- Relevant guidance may include CIBSE Guide C and CIBSE Guide B for fluid flow, pipe sizing and hydraulic system design considerations.
- Where applicable, final design should also align with relevant British Standards, project specifications and manufacturer requirements.