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
Concrete, k = 1.4150 mm19 °C-1 °CQ̇ = ?

A wall of concrete is 150 mm thick and has an area of 6 m². Its faces are held at 19 °C and -1 °C. Find the rate of heat conduction Q̇ through the wall.

k = 1.4 W/(m·K)L = 150 mmA = 6 m²T1 = 19 °CT2 = -1 °C
Q̇ = W
2.Easy
Expanded polystyrene, k = 0.03550 mm17 °C8 °Cq″ = ?

A wall of expanded polystyrene is 50 mm thick and has an area of 20 m². Its faces are held at 17 °C and 8 °C. Find the heat flux q″ through the wall.

k = 0.035 W/(m·K)L = 50 mmA = 20 m²T1 = 17 °CT2 = 8 °C
q″ = W/m²
3.Medium
Mineral wool, k = 0.04100 mmGypsum board, k = 0.17100 mm15 °C-11 °CQ̇ = ?

A wall is made of 100 mm of mineral wool and 100 mm of gypsum board, with an area of 4 m². The outer faces are at 15 °C and -11 °C. Find the heat flow Q̇ through the wall.

L1 = 100 mm, k1 = 0.04 W/(m·K)L2 = 100 mm, k2 = 0.17 W/(m·K)A = 4 m²T1 = 15 °CT3 = -11 °C
Q̇ = W
4.Medium
Brick, k = 0.72200 mmMineral wool, k = 0.0450 mm15 °C-14 °CQ̇ = ?

A wall is made of 200 mm of brick and 50 mm of mineral wool, with an area of 8 m². The outer faces are at 15 °C and -14 °C. Find the heat flow Q̇ through the wall.

L1 = 200 mm, k1 = 0.72 W/(m·K)L2 = 50 mm, k2 = 0.04 W/(m·K)A = 8 m²T1 = 15 °CT3 = -14 °C
Q̇ = W
5.Hard
Concrete, k = 1.4250 mmWood, k = 0.1775 mmroom 21 °Coutside -10 °CQ̇

A wall of 250 mm concrete and 75 mm wood separates a room at 21 °C from outside air at -10 °C. The convection coefficients are 10 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 12 m². Find the overall heat transfer coefficient U of the wall.

L1 = 250 mm, k1 = 1.4 W/(m·K)L2 = 75 mm, k2 = 0.17 W/(m·K)A = 12 m²hi = 10 W/(m²·K)ho = 20 W/(m²·K)Troom = 21 °CTout = -10 °C
U = W/(m²·K)
6.Hard
Wood, k = 0.1750 mmGypsum board, k = 0.17100 mmroom 21 °Coutside -9 °CQ̇

A wall of 50 mm wood and 100 mm gypsum board separates a room at 21 °C from outside air at -9 °C. The convection coefficients are 10 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 10 m². Find the overall heat transfer coefficient U of the wall.

L1 = 50 mm, k1 = 0.17 W/(m·K)L2 = 100 mm, k2 = 0.17 W/(m·K)A = 10 m²hi = 10 W/(m²·K)ho = 25 W/(m²·K)Troom = 21 °CTout = -9 °C
U = W/(m²·K)

Answer key

  1. 1. Q̇ = 1120 W
  2. 2. q″ = 6.3 W/m²
  3. 3. Q̇ = 33.68 W
  4. 4. Q̇ = 151.9 W
  5. 5. U = 1.299 W/(m²·K)
  6. 6. U = 0.9781 W/(m²·K)

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