Engineering calculator reviewed for preliminary design use · Last updated: March 2026
Calculate heat loss per unit length from an insulated pipe using cylindrical Fourier conduction law. Input insulation thickness, thermal conductivity, fluid temperature, and ambient temperature. Apply to insulation design and energy saving evaluation.
Pipe Insulation Heat Loss Calculation
Proper insulation of hot and cold process piping reduces energy losses and maintains process temperatures. Cylindrical insulation requires a logarithmic calculation (not the flat-wall approximation) for accurate results.
Formula (Cylindrical Insulation)
q = 2πLλ(T₁ − T₂) / ln(r₂/r₁)
q: Heat loss [W]
L: Pipe length [m]
λ: Insulation thermal conductivity [W/(m·K)]
T₁: Inner surface temperature (≈ fluid temperature) [°C]
Insulation thickness is typically selected by economic optimization — balancing insulation material cost against energy savings. Minimum thickness is also governed by personnel protection (surface temperature < 60°C) and condensation prevention.
What thermal conductivity values should I use?
Mineral wool: 0.035-0.045 W/(m·K), calcium silicate: 0.05-0.07, cellular glass: 0.04-0.05, polyurethane foam: 0.02-0.03. Values increase with temperature — use the mean temperature value.
These results are preliminary estimates for screening-level design use. They do not replace detailed engineering, code compliance verification, or vendor-certified calculations.