Reference no: EM132416394

A large warehouse building is heated during the winter to maintain interior temperatures at 18 C. On a certain day the outdoor temperature is constant at 5 C. The total roof area is 5000 m2. The wall area excluding windows and doors, is 3000 m2. The area of windows and doors is 250 m2. Ignore convection and radiation heat transfer mechanisms for parts a, b and c.

a) Compute the rate of heat transfer through the roof if it has an R-value of 3.1 m2-C/W.

b) Compute the rate of heat transfer through the walls (excluding windows and doors) if the walls have an effective thermal conductivity of 0.035 W/m-C and a thickness of 12 cm.

c) Compute the rate of heat transfer through the doors and windows assuming they have a total thermal resistance, R, of 0.00087 C/W.

d) The building is heated by a hot air furnace which is rated by the number of BTU/hour it can deliver. How many BTU/hour are needed to heat the building under the conditions indicated.