A wall of gypsum board is 100 mm thick and has an area of 8 m². Its faces are held at 16 °C and 6 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of expanded polystyrene is 50 mm thick and has an area of 12 m². Its faces are held at 21 °C and 4 °C. Find the heat flux q″ through the wall.
A wall is made of 250 mm of mineral wool and 150 mm of wood, with an area of 6 m². The outer faces are at 22 °C and 4 °C. Find the temperature Ti at the interface between the two layers.
A wall is made of 200 mm of expanded polystyrene and 100 mm of wood, with an area of 8 m². The outer faces are at 25 °C and 6 °C. Find the heat flow Q̇ through the wall.
A wall of 100 mm expanded polystyrene and 100 mm glass separates a room at 20 °C from outside air at -15 °C. The convection coefficients are 7.7 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 4 m². Find the overall heat transfer coefficient U of the wall.
A wall of 200 mm expanded polystyrene and 25 mm gypsum board separates a room at 20 °C from outside air at -6 °C. The convection coefficients are 10 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 8 m². Find the heat loss Q̇ through the wall.
Answer key
- 1. q″ = 17 W/m²
- 2. q″ = 11.9 W/m²
- 3. Ti = 6.227 °C
- 4. Q̇ = 24.12 W
- 5. U = 0.32 W/(m²·K)
- 6. Q̇ = 34.7 W
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