QUESTION $2($PO$2,$ CO$2,$ C$4)$

During a hot day, the temperature of environment air is $40C.$ A condominium with main wall dimension facing the outside is $15m4m0\mathrm{.}15m.$ The rest of the wall is either a shared wall to the adjacent units or facing the shaded hall way. If the condominium needs to be maintained at $20C,$ determine the heat that must be removed from the unit due to heat transfer to the main wall. The heat transfer coefficient for convection for outer and inner wall are taken as $25\frac{W}{m^2}K$ and $6\frac{W}{m^2}K,$ respectively.

$***$You need to construct the wall's detail layer according to the dimension given using a standard buildings material and find the appropriate conductivity value of each layer from the properties of buildings material.

$(20$ marks$)$