Question

The concrete slab of a basement is 11 m long, 8 m wide, and 0.20 m thick. During the winter, temperatures are nominally 17°C and 10°C at the top and bottom surfaces, respectively. If the concrete has a thermal conductivity of 1.4 W/m · K, what is the rate of heat loss through the slab? If the basement is heated by a gas furnace operating at an efficiency of ηf = 0.9

Answer 1

`(dQ)/(dt)= 4312 W`

Step-by-step explanation:

As we know that base of the slab is given as

`A = 11 * 8`

`A = 88 m^2`

now we know that rate of heat transfer is given as

`(dQ)/(dt) = (kA)/(x) (T_2 - T_1)`

here we know that

`k = 1.4 W/m k`

Also we have

`x =0.20`

`(dQ)/(dt) = (1.4(88))/(0.20)(17 - 10)`

`(dQ)/(dt)= 4312 W`