System Water Volume Estimator

Inputs

Pipework

15 mm Pipe Length (m)

22 mm Pipe Length (m)

28 mm Pipe Length (m)

35 mm Pipe Length (m)

42 mm Pipe Length (m)

54 mm Pipe Length (m)

Emitters / Terminals

Radiator / Trench Heater Quantity

Allowance per Emitter (L each)

Heating Coils / AHUs / FCUs Quantity

Allowance per Coil / Unit (L each)

Plant / Equipment

Boilers / Heat Source Allowance (L)

Buffer / Low Loss Header / Vessel Allowance (L)

Miscellaneous Allowance (L)

Pipe volumes are based on typical internal water content per metre for common heating pipe sizes. Final system volume should be verified against detailed design and manufacturer data.

Result

Estimated System Water Volume

Enter values and click calculate.

Method

Total system volume is estimated by summing pipework content, emitter allowances and plant allowances:

Vₜ = Vₚ + Vₑ + Vₚₗ

Pipework volume is estimated from length and typical water content per metre:

Vₚ = Σ (Pipe Length × Water Content per metre)

Vₜ = total estimated system volume (L)
Vₚ = total pipework water volume (L)
Vₑ = total emitter / terminal allowance (L)
Vₚₗ = total plant / equipment allowance (L)
Calculated result = -

Reference

This estimator is intended for preliminary system water content checks where a detailed schedule is not yet available.
Pipework content is based on typical internal water volumes for common heating pipe sizes.
Emitter and plant allowances should be refined using project equipment schedules and manufacturer data where available.
Where applicable, final design should align with project specifications, manufacturer requirements and associated vessel / pressurisation calculations.

Design note: This estimator provides indicative system water volume only. Final expansion vessel sizing and pressurisation design should be based on confirmed plant content, terminal content, detailed pipework lengths and manufacturer data.