Fourier Conduction Calculator

The physics behind insulation

Fourier's Law describes how heat flows through a solid material at steady state - it directly explains why thicker insulation reduces heat loss, why larger surface areas lose more heat, and why some materials conduct heat far better than others.

Worked example

For a 0.1m thick insulation panel (conductivity 0.04 W/m.K) with 10 m² of area and a 20K temperature difference across it:

Q = (0.04 x 10 x 20) / 0.1 = 80.0 W

Frequently asked questions

Why does doubling thickness halve heat loss? Thickness sits in the denominator of Fourier's Law - doubling the distance heat must travel through the material halves the temperature gradient driving that heat flow, directly halving the conduction rate for the same temperature difference.

What makes a good insulator? Materials with low thermal conductivity (like the 0.04 W/m.K value used above, typical of fiberglass or foam insulation) conduct heat slowly - compare this to solid metals, which can have conductivities several hundred times higher and conduct heat almost instantly by comparison.