A wall of mineral wool is 20 mm thick and has an area of 6 m². Its faces are held at 17 °C and -7 °C. Find the heat flux q″ through the wall.
Heat conduction worksheet with answers
A wall of glass is 10 mm thick and has an area of 6 m². Its faces are held at 22 °C and -9 °C. Find the heat flux q″ through the wall.
A wall is made of 200 mm of gypsum board and 75 mm of brick, with an area of 10 m². The outer faces are at 25 °C and 5 °C. Find the temperature Ti at the interface between the two layers.
A wall is made of 50 mm of mineral wool and 100 mm of gypsum board, with an area of 10 m². The outer faces are at 23 °C and -3 °C. Find the heat flow Q̇ through the wall.
A wall of 200 mm glass and 50 mm gypsum board separates a room at 22 °C from outside air at -4 °C. The convection coefficients are 10 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 4 m². Find the heat loss Q̇ through the wall.
A wall of 150 mm glass and 100 mm concrete separates a room at 22 °C from outside air at -14 °C. The convection coefficients are 7.7 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 10 m². Find the overall heat transfer coefficient U of the wall.
Answer key
- 1. q″ = 48 W/m²
- 2. q″ = 2976 W/m²
- 3. Ti = 6.627 °C
- 4. Q̇ = 141.4 W
- 5. Q̇ = 159.4 W
- 6. U = 2.454 W/(m²·K)
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