Calculate the heat loss through the walls and ceiling for a median-sized home in your hometown (or your own home) for the worst-case summer conditions and the worst-case winter conditions, given the following information. To simplify the problem, you may neglect the effect of windows and doors. You may also ignore the effect of contact resistances. Further, radiation effects may be neglected. Provide a detailed tabulation of any additional assumptions you make, with suitable justification. The walls are a sandwich construction comprised of an 18-mm thick layer of sheetrock (gypsum), attached to 2 " x 4" (actual dimensions are smaller) pine studs at a center-to-center distance of 40 cm. The space between the studs is filled with glass fiber insulation. The insulation is covered with a 10-mm thick polystyrene board. The outermost layer is 10-cm thick common brick. The heat transfer coefficient for the inside of the home may be assumed to be 5 W/m•K, and the outside heat transfer coefficient may be assumed to be 12 W/m°•K.
The ceiling composition is 18-mm sheetrock attached to 2 " X 6" (actual dimensions are smaller) pine ceiling joists at a center-to-center distance of 50 cm. Glass fiber insulation fills the gap between the ceiling joists. The heat transfer coefficient in the attic space may be assumed to be 5 W/m2.K.
Explore the effect of the variation in outside heat transfer coefficient by plotting heat loss as a function of outside heat transfer coefficient for hout values ranging from 5 to 30 W/m. K.