b. Heat transfer The wall of the cabin mentioned above is made of two layers. The outer layer is made of steel with thermal conductivity of Ks = 43 W/mK and is 3mm thick. The inner layer is made of glass wool with thermal conductivity of KG = 0.05 W/mK and is 50mm thick. The convective heat transfer coefficient between the outside air and the outer surface of the wall is ho = 7 W/m2K and between the inside air and the inner surface of the wall is h; = 4 W/m2K. The outside air temperature is -20C and the inside air temperature is 10C. Both inner and outer surfaces of the wall are covered with a paint that blocks radiation emission and absorption completely, so radiation heat transfer can be neglected, both inside and outside. i. What is the total thermal resistance between the inside air and the outside air for 1m of the wall? [8 marks] ii. What is the rate of heat transfer through 1m of the wall? [2 marks] Inside air Glass wool Outside air Steel Direction of heat flow