Awall with an area of 25m² is made up of four layers. on the inside is plaster 15mm thick, then there is brick 100mm thick, then insulation 60mm thick and finally brick 100mm thick. the thermal conductivity of plaster is 0.1 w/mk the thermal conductivity of brick is 0.6w/mk the thermal conductivity of the insulations is 0.08w/mk the one side of the wall is in contact with air at 22°c and the other with air at -5°c. the surface heat transfer coefficient for both surfaces is 0.006 w/m²k. calculate the heat loss and the overall heat transfer coefficient.