All toolsCalculatorsInsulationEconomic Insulation Thickness

Economic Insulation Thickness

Least-cost insulation thickness by minimising annualised capital plus annual heat-loss energy cost.

Pipe outside Ø

Bare steel OD (e.g. DN50 = 60.3)

Conductivity (k)

W/m·K

Design λ — mineral wool ≈ 0.040

Surface film (h)

W/m²·K

Light air movement ≈ 10

Fluid / pipe surface

°C

Ambient air

°C

Run length

Scales the £ figures, not the optimum thickness

Operating hours / year

h/yr

Energy cost

£/kWh

Generation efficiency

frac

Boiler η, or a COP > 1 for a heat pump

Insulant cost

£/m³

Installed cost per m³ — supply your quote

Interest / discount rate

0 → simple straight-line (CRF = 1/n)

Evaluation period

Max thickness

Upper bound of the candidate sweep

Step

Candidate granularity (5 mm = commercial sections)

Enter the pipe and cost inputs to find the economic insulation thickness