A wall of glass is 50 mm thick and has an area of 8 m². Its faces are held at 24 °C and 10 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of expanded polystyrene is 20 mm thick and has an area of 20 m². Its faces are held at 15 °C and -10 °C. Find the heat flux q″ through the wall.
A wall is made of 50 mm of wood and 150 mm of brick, with an area of 6 m². The outer faces are at 21 °C and -3 °C. Find the heat flow Q̇ through the wall.
A wall is made of 50 mm of glass and 75 mm of wood, with an area of 4 m². The outer faces are at 21 °C and -7 °C. Find the temperature Ti at the interface between the two layers.
A wall of 50 mm glass and 50 mm wood 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 6 m². Find the temperature Ts of the inside surface of the wall.
A wall of 200 mm mineral wool and 150 mm gypsum board separates a room at 20 °C from outside air at -5 °C. The convection coefficients are 6 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 10 m². Find the heat loss Q̇ through the wall.
Answer key
- 1. q″ = 268.8 W/m²
- 2. q″ = 43.75 W/m²
- 3. Q̇ = 286.6 W
- 4. Ti = 18.04 °C
- 5. Ts = 11.64 °C
- 6. Q̇ = 41.1 W
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