The length and breadth of a basement floor are 16 m and 12 m respectively and it is 2 m below grade. The 150 mm thick floor is made of concrete (k = 2.2 Wmí1 Kí1 ), and it is entirely carpeted. The...

The length and breadth of a basement floor are 16 m and 12 m respectively and it is 2 m below grade. The 150 mm thick floor is made of concrete (k = 2.2 Wmí1 Kí1 ), and it is entirely carpeted. The carpet is 10 mm thick and its thermal conductivity is 0.1 Wmí1 Kí1 . The soil surrounding the basement has a thermal conductivity of 1.4 Wmí1 Kí1 . The inside air temperature is 18°C and the outside ambient temperature is í3°C. The inside and outside heat transfer coefficients are 10 Wmí2 Kí1 and 27 Wmí2 Kí1 respectively. Calculate (i) the average heat transfer coefficient for the basement floor, and (ii) the total rate of heat loss through the basement floor.