ClueLuma

Remaining-layer equilibrium calculator

Combine the resistance after an interface to back-calculate that interface temperature.

Units
q=ti1−taRi2+Rsq = \frac{t_{\text{i1}} - t_{a}}{R_{\text{i2}} + R_{s}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

°F
°F
h·ft²·°F/Btu
Btu/(h·ft²)

Worked example

Given

  • ti1t_{\text{i1}} = 170 °F
  • tat_{a} = 70 °F
  • Ri2+RsR_{\text{i2}} + R_{s} = 10 h·ft²·°F/Btu
q=170−7010=10q = \frac{170 - 70}{10} = 10

Symbols and units

SymbolMeaningUnit
qqsteady heat fluxBtu/(h·ft²)
ti1t_{\text{i1}}temperature after layer 1°F
tat_{a}ambient temperature°F
Ri2+RsR_{\text{i2}} + R_{s}remaining resistanceh·ft²·°F/Btu

Related calculators

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.