“Heat, like gravity, penetrates every substance of the universe, its rays occupy all parts of space.”

-Jean-Baptiste-Joseph Fourier, mathematician and physicist.

Heat is an important form of energy, and it is practically all around us. Almost every building uses heat to create a comfortable temperature, for every meal heat is used to cook ingredients, and there are much more examples. This lecture will analyse the heating demand of a building, and the thermal heat constant is introduced.