A wall of gypsum board is 100 mm thick and has an area of 10 m². Its faces are held at 25 °C and 9 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of gypsum board is 150 mm thick and has an area of 15 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 200 mm of glass and 25 mm of expanded polystyrene, with an area of 10 m². The outer faces are at 23 °C and -5 °C. Find the heat flow Q̇ through the wall.
A wall is made of 250 mm of expanded polystyrene and 25 mm of brick, with an area of 15 m². The outer faces are at 16 °C and -1 °C. Find the temperature Ti at the interface between the two layers.
A wall of 50 mm expanded polystyrene and 150 mm mineral wool separates a room at 20 °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 6 m². Find the heat loss Q̇ through the wall.
A wall of 200 mm wood and 100 mm mineral wool separates a room at 22 °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 15 m². Find the heat loss Q̇ through the wall.
Answer key
- 1. q″ = 27.2 W/m²
- 2. Q̇ = 238 W
- 3. Q̇ = 303.5 W
- 4. Ti = −0.9178 °C
- 5. Q̇ = 16.8 W
- 6. Q̇ = 144.5 W
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