A wall of glass is 50 mm thick and has an area of 15 m². Its faces are held at 18 °C and -13 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of wood is 10 mm thick and has an area of 6 m². Its faces are held at 22 °C and 8 °C. Find the rate of heat conduction Q̇ through the wall.
A wall is made of 150 mm of gypsum board and 50 mm of glass, with an area of 8 m². The outer faces are at 20 °C and 7 °C. Find the temperature Ti at the interface between the two layers.
A wall is made of 250 mm of concrete and 50 mm of brick, with an area of 15 m². The outer faces are at 16 °C and 9 °C. Find the temperature Ti at the interface between the two layers.
A wall of 150 mm concrete and 50 mm expanded polystyrene separates a room at 22 °C from outside air at -13 °C. The convection coefficients are 6 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 15 m². Find the heat loss Q̇ through the wall.
A wall of 250 mm gypsum board and 25 mm glass separates a room at 20 °C from outside air at -7 °C. The convection coefficients are 10 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 6 m². Find the overall heat transfer coefficient U of the wall.
Answer key
- 1. q″ = 595.2 W/m²
- 2. Q̇ = 1428 W
- 3. Ti = 7.725 °C
- 4. Ti = 10.96 °C
- 5. Q̇ = 299.6 W
- 6. U = 0.6135 W/(m²·K)
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