Question

A wall, 4x6 meters by 0.1m thick, experiences temperatures of 30°C on one side and 8°C on the other. The rate of heat transfer through the wall is 900 Watts. What is the thermal conductivity of the wall, and what is it probably made of?

Answer 1

Answer:

$thermal conductivity k = 0,17045 \frac{W }{m * °C}$

It is probably made of wood

Explanation:

The heat transmission for the wall is:

$Q =  \frac{k * A * dT}{e}$

Where k is the conductivity, A the area, dT the thermal gradient, and e the thickness.

Solving for k:

$k =  \frac{Q * e}{A * dT}$

replacing:

$A = 4m * 6m = 24 m2$

$e = 0,1 m$

$Q = 900 W$

$dT = 30 - 8 = 22 °C$

$k = 0,17045 \frac{W }{m * °C}$

The wood has conductivity values between 0,14 and 0,22 w/m°C