Problem Set #8 Conduction Heat Transfer Suppose you are contemplating whether you should add a layer of insulation to your w house walls. The existing wall consists of an exxterior brick layer (k = 0.72 C) that is m n 15 cm thick, in series with an interior layer of plaster (k = 0.22 %) that is 2 cm thick. You are considering the addition of a 2 cmthick layer of foam insulation (k = 0.026 %) added to the entire wall area. Ifthe total wall area is 150 ml, the outside temperature is 0' C, and the inside temperature is 24" C, find: a. The heat loss (in Watts) to the outside air before adding insulation b. The heat loss (in Watts) to the outside air after adding insulation A biomass-fired electricity generation plant has a steel steam pipe from the boiler to the turbine. The pipe has an inner diameter of 30 cm and an outer diameter of 34 cm. It is wrapped in a layer of insulation 5 cm thick. The temperature of the steam inside the pipe is 200 C and the pipe's exterior temperature (at the exterior of the insulation) is 30" C. The pipe is 20 m long. Calculate the heat loss from the pipe if the steel has conductivity k = 60 % and the insulation has conductivity k = 0.03 %. 25