Heat conductance - linear? Hello forum friends, I have stumbled upon the fallowing heat conduction problem: Consider a heat source of constant power embedded inside a solid with a constant heat capacity and conductance. Around the source is a box with a constant temperature, which cools the source. My question is: If the box is a cube, can I conclude that each side contributes equally to the cooling? If I had just one side (out of 6) could I conclude 1/6 cooling? However if the box is not a cube. Two opposite sides are pulled 2 times further off, can I conclude a cooling of 1/2 about these sides? Is heat conductance in two or three dimensions a linear problem?