Exhaust Heat Loss Calculator
Estimate exhaust temperature drop per foot of pipe for mild steel, stainless, Inconel, ceramic-coated, or wrapped tubing.
How to Use
- Enter inlet EGT, pipe OD, wall thickness, length, and ambient temp.
- Select material / finish — emissivity drives radiation losses.
- Toggle wrap / heat shield to see impact on exit temperature.
Gas & pipe
Finish
Heat loss
Formulas
Convection
q_c = h · A · (T_s - T_∞)
Radiation
q_r = ε · σ · A · (T_s⁴ - T_∞⁴)
Gas ΔT per foot
ΔT/ft = q_total / (ṁ · c_p)
Exhaust c_p
c_p ≈ 0.26 Btu/(lb·°F)
Frequently Asked Questions
Why insulate headers?
Keeps pulse energy in the gas = stronger scavenging + faster turbo spool. Also protects underhood components.
Wrap vs coating?
Wrap is cheapest (-60-80% radiation) but traps moisture and cooks stainless. Coating lasts forever but is slightly less effective.
Does bigger pipe lose more heat?
Yes — larger surface area. But gas velocity drops too, so contact time per foot increases. Net: bigger = more ΔT per foot.
Common Use Cases
Turbo inlet
Check how much EGT is lost between header and turbine flange.
Underhood thermal load
Estimate radiative watts into the engine bay.
Coating ROI
See the ΔT gain from ceramic coat vs raw.
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