Problem #1: Consider a building wall consisting of: Outer layer of common brick: Insulation layer of Celotex sheating: tbrick = 10 cm tcelo = 1.25 cm Kbrick -0.69 W/mC Keelo 0.048 W/mC Inner air gap defined by wall studs. tstuds 10 cm The studs are The air is Inside wall of sheetrock: The outside surface the brick is at a temperature of: The inner surface of the sheetrock is at a temperature of: Find the R-value for the wall. b.) Calculate the heat transfer rate through one square meter of the wall. c.) Calculate the temperature between the brick and the Celotex sheathing. Wstuds = 4.33 cm kstud 0.78 W/mC Wair-29 cm Kair 0.03 W/mC kyp = 1.25 cm Kgyp = 0.744 W/mC Tout 0 C. I in = 22 C. Problem #2: Consider the same building wall, but now include the effects of convective and radiative heat transfer at the surfaces. Note: The surface temperatures will not be the same as problem #1. Take the outside air temperature to be: Take the inside air temperature to be: Tout = 0 C. Tin = 22 C. Wind blows over the outside of the brick wall, moves at velocity: Vair Air kinematic viscosity Air thermal conductivity Air thermal diffusivity = 20 m/s. v = 1.4 x 10-5 m/s k = 0.025 W/m-K a = 2.0 x 10-5 m/s Laminar Flow over a Flat Plate, Average Heat Transfer: Turbulent Flow over a Flat Plate, Average Heat Transfer: Nu 0.664REL 1/2 Pr/3 4/5-871)Pr1/3 Nu (0.037ReL Air inside the room transfers heat to the wall by natural convection: Radiative heat transfer from the brick wall to the outside: from the inside wall to the room: Stefan Boltzman h=5 W/mK =0.9 =0.9 5.67x10-8 W/m-K4 a.) Find the R-value for the wall including convection and radiation. b.) Calculate the heat transfer rate through one square meter of the wall. c.) Calculate the temperature at the surface of the sheetrock in the room.