Heat conduction worksheet with answers

Free printable Heat conduction worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
Mineral wool, k = 0.04150 mm19 °C0 °CQ̇ = ?

A wall of mineral wool is 150 mm thick and has an area of 12 m². Its faces are held at 19 °C and 0 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.04 W/(m·K)L = 150 mmA = 12 m²T1 = 19 °CT2 = 0 °C
Q̇ = W
2.Easy
Mineral wool, k = 0.04150 mm19 °C10 °Cq″ = ?

A wall of mineral wool is 150 mm thick and has an area of 10 m². Its faces are held at 19 °C and 10 °C. Find the heat flux q″ through the wall.

k = 0.04 W/(m·K)L = 150 mmA = 10 m²T1 = 19 °CT2 = 10 °C
q″ = W/m²
3.Medium
Expanded polystyrene, k = 0.035150 mmMineral wool, k = 0.04150 mm19 °C1 °CQ̇ = ?

A wall is made of 150 mm of expanded polystyrene and 150 mm of mineral wool, with an area of 8 m². The outer faces are at 19 °C and 1 °C. Find the heat flow Q̇ through the wall.

L1 = 150 mm, k1 = 0.035 W/(m·K)L2 = 150 mm, k2 = 0.04 W/(m·K)A = 8 m²T1 = 19 °CT3 = 1 °C
Q̇ = W
4.Medium
Brick, k = 0.72150 mmExpanded polystyrene, k = 0.03550 mm18 °C-4 °CQ̇ = ?

A wall is made of 150 mm of brick and 50 mm of expanded polystyrene, with an area of 8 m². The outer faces are at 18 °C and -4 °C. Find the heat flow Q̇ through the wall.

L1 = 150 mm, k1 = 0.72 W/(m·K)L2 = 50 mm, k2 = 0.035 W/(m·K)A = 8 m²T1 = 18 °CT3 = -4 °C
Q̇ = W
5.Hard
Brick, k = 0.72150 mmGypsum board, k = 0.1750 mmroom 20 °Coutside 4 °CQ̇

A wall of 150 mm brick and 50 mm gypsum board separates a room at 20 °C from outside air at 4 °C. The convection coefficients are 6 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 8 m². Find the overall heat transfer coefficient U of the wall.

L1 = 150 mm, k1 = 0.72 W/(m·K)L2 = 50 mm, k2 = 0.17 W/(m·K)A = 8 m²hi = 6 W/(m²·K)ho = 20 W/(m²·K)Troom = 20 °CTout = 4 °C
U = W/(m²·K)
6.Hard
Glass, k = 0.96200 mmBrick, k = 0.7275 mmroom 22 °Coutside 5 °CQ̇

A wall of 200 mm glass and 75 mm brick separates a room at 22 °C from outside air at 5 °C. The convection coefficients are 10 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 12 m². Find the overall heat transfer coefficient U of the wall.

L1 = 200 mm, k1 = 0.96 W/(m·K)L2 = 75 mm, k2 = 0.72 W/(m·K)A = 12 m²hi = 10 W/(m²·K)ho = 30 W/(m²·K)Troom = 22 °CTout = 5 °C
U = W/(m²·K)

Answer key

  1. 1. Q̇ = 60.8 W
  2. 2. q″ = 2.4 W/m²
  3. 3. Q̇ = 17.92 W
  4. 4. Q̇ = 107.5 W
  5. 5. U = 1.391 W/(m²·K)
  6. 6. U = 2.243 W/(m²·K)

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