Consider a multilayer wall, $7-$meter$-$wide, and $3-$meter$-$high, made up of the following layers $($from outside to inside$)$

Layer $1$: $200mm$ clay tile, hollow $(3$ cells deep$)$

Layer $2$: $90mm$ air gap $(($:$E_b=0\mathrm{.}82$;$T_{\text{d}\text{i}\text{f}\text{f}}=6C$;$T_{\text{m}\text{e}\text{a}\text{n}}=32\mathrm{.}2C\}$

Layer $3$: $100mm$ Sand and gravel aggregate concretes $(2240\frac{kg}{m^3})$

Layer $4$: $20mm$ Cement plaster $($sand aggregate$)$

The season is winter with an outside temperature of $5C,$ and the inside temperature is maintained at $23C.$ If the emissivity is equal to $0\mathrm{.}9,$ do the following:

Calculate overall heat transfer coefficient for the wall $(U_{\text{w}\text{a}\text{l}\text{l}}).$

Calculate the heat loss from the wall in $kW.$

Calculate the temperature at the interface of each layer and draw the temperature profile across the wall.