A wall of mineral wool is 50 mm thick and has an area of 8 m². Its faces are held at 15 °C and -4 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of wood is 100 mm thick and has an area of 8 m². Its faces are held at 17 °C and 4 °C. Find the rate of heat conduction Q̇ through the wall.
A wall is made of 200 mm of gypsum board and 100 mm of wood, with an area of 6 m². The outer faces are at 24 °C and 6 °C. Find the heat flow Q̇ through the wall.
A wall is made of 100 mm of brick and 75 mm of expanded polystyrene, with an area of 8 m². The outer faces are at 15 °C and -14 °C. Find the temperature Ti at the interface between the two layers.
A wall of 250 mm glass and 25 mm brick separates a room at 22 °C from outside air at 2 °C. The convection coefficients are 8 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 12 m². Find the heat loss Q̇ through the wall.
A wall of 50 mm wood and 100 mm mineral wool separates a room at 22 °C from outside air at -11 °C. The convection coefficients are 7.7 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″ = 15.2 W/m²
- 2. Q̇ = 176.8 W
- 3. Q̇ = 61.2 W
- 4. Ti = 13.23 °C
- 5. Q̇ = 510.5 W
- 6. Q̇ = 89.27 W
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