A wall of concrete is 200 mm thick and has an area of 6 m². Its faces are held at 19 °C and 7 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of wood is 50 mm thick and has an area of 12 m². Its faces are held at 21 °C and -3 °C. Find the heat flux q″ through the wall.
A wall is made of 100 mm of mineral wool and 100 mm of gypsum board, with an area of 12 m². The outer faces are at 21 °C and 8 °C. Find the heat flow Q̇ through the wall.
A wall is made of 50 mm of concrete and 100 mm of mineral wool, with an area of 12 m². The outer faces are at 17 °C and -6 °C. Find the heat flow Q̇ through the wall.
A wall of 150 mm brick and 25 mm glass separates a room at 21 °C from outside air at -12 °C. The convection coefficients are 6 W/(m²·K) inside and 20 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 75 mm glass separates a room at 22 °C from outside air at -5 °C. The convection coefficients are 7.7 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 12 m². Find the overall heat transfer coefficient U of the wall.
Answer key
- 1. q″ = 84 W/m²
- 2. q″ = 81.6 W/m²
- 3. Q̇ = 50.51 W
- 4. Q̇ = 108.8 W
- 5. Ts = 8.806 °C
- 6. U = 2.291 W/(m²·K)
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