A wall of glass is 50 mm thick and has an area of 8 m². Its faces are held at 20 °C and -10 °C. Find the rate of heat conduction Q̇ through the wall.
Heat conduction worksheet with answers
A wall of gypsum board is 10 mm thick and has an area of 12 m². Its faces are held at 20 °C and -1 °C. Find the heat flux q″ through the wall.
A wall is made of 150 mm of gypsum board and 50 mm of concrete, with an area of 6 m². The outer faces are at 24 °C and 8 °C. Find the temperature Ti at the interface between the two layers.
A wall is made of 100 mm of wood and 75 mm of mineral wool, with an area of 10 m². The outer faces are at 18 °C and -6 °C. Find the heat flow Q̇ through the wall.
A wall of 150 mm glass and 50 mm gypsum board separates a room at 21 °C from outside air at 2 °C. The convection coefficients are 7.7 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 15 m². Find the overall heat transfer coefficient U of the wall.
A wall of 250 mm expanded polystyrene and 50 mm concrete separates a room at 20 °C from outside air at -8 °C. The convection coefficients are 8 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 15 m². Find the overall heat transfer coefficient U of the wall.
Answer key
- 1. Q̇ = 4608 W
- 2. q″ = 357 W/m²
- 3. Ti = 8.622 °C
- 4. Q̇ = 97.43 W
- 5. U = 1.587 W/(m²·K)
- 6. U = 0.1362 W/(m²·K)
Full step-by-step solutions: practise this topic on examproblems.com.