Question

Find the energy transferred in 1 h by conduction through a concrete wall 2 m high, 3.65 m long, and 0.20 m thick if one side of the wall is held at 20∘C and the other side is at 5∘C.

Answer 1

The Fourier law of heat conductivity says

$$Q=P\tau=k\frac{\Delta T}{\Delta h}A\tau$$

$$Q=1.9*\frac{20-5}{0.20}*2*3.65*1*3600\\ =3.7*10^6\:\rm J$$