A freezer of dimensions 4 m wide, 6 m long and 3 m high is under construction. The walls and ceiling are composed of 1.7 mm stainless steel (k = 15 W / [m ° C]), 10 cm thick foam insulation (k = 0.036...

A freezer of dimensions 4 m wide, 6 m long and 3 m high is under construction. The walls and ceiling are composed of 1.7 mm stainless steel (k = 15 W / [m ° C]), 10 cm thick foam insulation (k = 0.036 W / [m ° C]), certain thickness of corkboard (k = 0.043 W / [m ° C]), and 1.27 cm thick wood (k = 0.104 W / [m ° C]). The inside of the freezer is maintained at -30 ° C. The ambient air outside the freezer is 32 ° C. The convective heat transfer coefficient is 5 W / (m K) on wooden walls and 2 W / (m² K) on stainless steel surfaces. If the outside air has a dew point of 29 ° C, calculate the thickness of the corkboard insulation that will prevent moisture condensation on the outer walls of the freezer. Calculate the rate of heat transfer through the walls and ceiling of this freezer. Ignore heat transfer from floors and corners of buildings.

 a. Thickness of corkboard insulation = Answer

  cm.

 b. Heat transfer rate through walls and ceiling = Answer

  watts.