A wall of concrete is 20 mm thick and has an area of 8 m². Its faces are held at 23 °C and -4 °C. Find the rate of heat conduction Q̇ through the wall.
Heat conduction worksheet with answers
A wall of gypsum board is 50 mm thick and has an area of 15 m². Its faces are held at 21 °C and -6 °C. Find the heat flux q″ through the wall.
A wall is made of 50 mm of expanded polystyrene and 150 mm of wood, with an area of 15 m². The outer faces are at 22 °C and -13 °C. Find the temperature Ti at the interface between the two layers.
A wall is made of 200 mm of gypsum board and 150 mm of glass, with an area of 15 m². The outer faces are at 19 °C and 4 °C. Find the heat flow Q̇ through the wall.
A wall of 250 mm mineral wool and 150 mm wood separates a room at 22 °C from outside air at 1 °C. The convection coefficients are 10 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 20 m². Find the temperature Ts of the inside surface of the wall.
A wall of 250 mm concrete and 150 mm mineral wool separates a room at 21 °C from outside air at 0 °C. The convection coefficients are 10 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 10 m². Find the overall heat transfer coefficient U of the wall.
Answer key
- 1. Q̇ = 15120 W
- 2. q″ = 91.8 W/m²
- 3. Ti = 0.3636 °C
- 4. Q̇ = 168.8 W
- 5. Ts = 21.71 °C
- 6. U = 0.2462 W/(m²·K)
Full step-by-step solutions: practise this topic on examproblems.com.