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
Gypsum board, k = 0.1750 mm23 °C6 °CQ̇ = ?

A wall of gypsum board is 50 mm thick and has an area of 4 m². Its faces are held at 23 °C and 6 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.17 W/(m·K)L = 50 mmA = 4 m²T1 = 23 °CT2 = 6 °C
Q̇ = W
2.Easy
Glass, k = 0.96250 mm18 °C-13 °CQ̇ = ?

A wall of glass is 250 mm thick and has an area of 15 m². Its faces are held at 18 °C and -13 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.96 W/(m·K)L = 250 mmA = 15 m²T1 = 18 °CT2 = -13 °C
Q̇ = W
3.Medium
Glass, k = 0.96250 mmWood, k = 0.17150 mm15 °C-7 °CTi​ = ?Q̇

A wall is made of 250 mm of glass and 150 mm of wood, with an area of 10 m². The outer faces are at 15 °C and -7 °C. Find the temperature Ti at the interface between the two layers.

L1 = 250 mm, k1 = 0.96 W/(m·K)L2 = 150 mm, k2 = 0.17 W/(m·K)A = 10 m²T1 = 15 °CT3 = -7 °C
Ti = °C
4.Medium
Concrete, k = 1.4250 mmGlass, k = 0.9650 mm22 °C-15 °CTi​ = ?Q̇

A wall is made of 250 mm of concrete and 50 mm of glass, with an area of 15 m². The outer faces are at 22 °C and -15 °C. Find the temperature Ti at the interface between the two layers.

L1 = 250 mm, k1 = 1.4 W/(m·K)L2 = 50 mm, k2 = 0.96 W/(m·K)A = 15 m²T1 = 22 °CT3 = -15 °C
Ti = °C
5.Hard
Concrete, k = 1.450 mmWood, k = 0.1750 mmroom 21 °Coutside -4 °CQ̇

A wall of 50 mm concrete and 50 mm wood separates a room at 21 °C from outside air at -4 °C. The convection coefficients are 6 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 20 m². Find the overall heat transfer coefficient U of the wall.

L1 = 50 mm, k1 = 1.4 W/(m·K)L2 = 50 mm, k2 = 0.17 W/(m·K)A = 20 m²hi = 6 W/(m²·K)ho = 25 W/(m²·K)Troom = 21 °CTout = -4 °C
U = W/(m²·K)
6.Hard
Mineral wool, k = 0.0450 mmGypsum board, k = 0.1750 mmroom 20 °Coutside -6 °CQ̇

A wall of 50 mm mineral wool and 50 mm gypsum board separates a room at 20 °C from outside air at -6 °C. The convection coefficients are 6 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 = 50 mm, k1 = 0.04 W/(m·K)L2 = 50 mm, k2 = 0.17 W/(m·K)A = 12 m²hi = 6 W/(m²·K)ho = 20 W/(m²·K)Troom = 20 °CTout = -6 °C
U = W/(m²·K)

Answer key

  1. 1. Q̇ = 231.2 W
  2. 2. Q̇ = 1786 W
  3. 3. Ti = 9.987 °C
  4. 4. Ti = −6.645 °C
  5. 5. U = 1.864 W/(m²·K)
  6. 6. U = 0.5679 W/(m²·K)

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