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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
Expanded polystyrene, k = 0.035250 mm21 °C10 °CQ̇ = ?

A wall of expanded polystyrene is 250 mm thick and has an area of 10 m². Its faces are held at 21 °C and 10 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.035 W/(m·K)L = 250 mmA = 10 m²T1 = 21 °CT2 = 10 °C
Q̇ = W
2.Easy
Expanded polystyrene, k = 0.03550 mm18 °C-8 °Cq″ = ?

A wall of expanded polystyrene is 50 mm thick and has an area of 10 m². Its faces are held at 18 °C and -8 °C. Find the heat flux q″ through the wall.

k = 0.035 W/(m·K)L = 50 mmA = 10 m²T1 = 18 °CT2 = -8 °C
q″ = W/m²
3.Medium
Expanded polystyrene, k = 0.035250 mmWood, k = 0.1775 mm17 °C0 °CTi​ = ?Q̇

A wall is made of 250 mm of expanded polystyrene and 75 mm of wood, with an area of 15 m². The outer faces are at 17 °C and 0 °C. Find the temperature Ti at the interface between the two layers.

L1 = 250 mm, k1 = 0.035 W/(m·K)L2 = 75 mm, k2 = 0.17 W/(m·K)A = 15 m²T1 = 17 °CT3 = 0 °C
Ti = °C
4.Medium
Expanded polystyrene, k = 0.035150 mmGlass, k = 0.9650 mm18 °C-14 °CTi​ = ?Q̇

A wall is made of 150 mm of expanded polystyrene and 50 mm of glass, with an area of 8 m². The outer faces are at 18 °C and -14 °C. Find the temperature Ti at the interface between the two layers.

L1 = 150 mm, k1 = 0.035 W/(m·K)L2 = 50 mm, k2 = 0.96 W/(m·K)A = 8 m²T1 = 18 °CT3 = -14 °C
Ti = °C
5.Hard
Glass, k = 0.96150 mmWood, k = 0.1725 mmroom 22 °Coutside -4 °CQ̇

A wall of 150 mm glass and 25 mm wood separates a room at 22 °C from outside air at -4 °C. The convection coefficients are 7.7 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 = 150 mm, k1 = 0.96 W/(m·K)L2 = 25 mm, k2 = 0.17 W/(m·K)A = 12 m²hi = 7.7 W/(m²·K)ho = 20 W/(m²·K)Troom = 22 °CTout = -4 °C
U = W/(m²·K)
6.Hard
Gypsum board, k = 0.17100 mmWood, k = 0.1725 mmroom 20 °Coutside -8 °CTs​ = ?Q̇

A wall of 100 mm gypsum board and 25 mm wood separates a room at 20 °C from outside air at -8 °C. The convection coefficients are 6 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 10 m². Find the temperature Ts of the inside surface of the wall.

L1 = 100 mm, k1 = 0.17 W/(m·K)L2 = 25 mm, k2 = 0.17 W/(m·K)A = 10 m²hi = 6 W/(m²·K)ho = 20 W/(m²·K)Troom = 20 °CTout = -8 °C
Ts = °C

Answer key

  1. 1. Q̇ = 15.4 W
  2. 2. q″ = 18.2 W/m²
  3. 3. Ti = 0.9889 °C
  4. 4. Ti = −13.62 °C
  5. 5. U = 2.07 W/(m²·K)
  6. 6. Ts = 15.1 °C

Full step-by-step solutions: practise this topic on examproblems.com.