A house is built on a sloping lot such that the back concret

A house is built on a sloping lot such that the back concrete basement wall is exposed. This uninsulated wall is 3 m high, 11 m wide, and t = 0.2 m thick. In winter weather, the outside wall surface is 5o C, while the inside surface is maintained at 25o C by the HVAC unit. Assuming the temperature gradient within the thickness of the wall to be linear, estimate the rate of heat loss, q, in units of W if the material thermal conductivity of the concrete is k = 1.2 W/(m K).

Solution

Q= kA(T2-T1)/L

K= thermal conductivity

A= area

L= thickness

Q= 1.2*3*11*(20)/0.2=3960 W

Heat loss through wall = 3960 w