Question-

The average thermal conductivity of the walls and roof of a house is 4.8 x 10"4 kW m"1°C~1 and their average thickness is 21.0 cm. The house is heated with natural gas,with a heat of combustion (energy released per cubic metre of gas burned) of 9300 kcal.m"3. How many cubic metres of gas must be burned each day to maintain an inside temperature of 25.0°C when the outside temperature is 0.0°C? The house may be treated as a rectangular box of height 5.00m and with sides of 8.00m and 10.00m in length. Disregard heat loss through the ground.