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
Glass, k = 0.96250 mm17 °C-3 °Cq″ = ?

A wall of glass is 250 mm thick and has an area of 8 m². Its faces are held at 17 °C and -3 °C. Find the heat flux q″ through the wall.

k = 0.96 W/(m·K)L = 250 mmA = 8 m²T1 = 17 °CT2 = -3 °C
q″ = W/m²
2.Easy
Concrete, k = 1.4150 mm21 °C-15 °Cq″ = ?

A wall of concrete is 150 mm thick and has an area of 10 m². Its faces are held at 21 °C and -15 °C. Find the heat flux q″ through the wall.

k = 1.4 W/(m·K)L = 150 mmA = 10 m²T1 = 21 °CT2 = -15 °C
q″ = W/m²
3.Medium
Glass, k = 0.96250 mmBrick, k = 0.72100 mm17 °C-2 °CTi​ = ?Q̇

A wall is made of 250 mm of glass and 100 mm of brick, with an area of 12 m². The outer faces are at 17 °C and -2 °C. Find the temperature Ti at the interface between the two layers.

L1 = 250 mm, k1 = 0.96 W/(m·K)L2 = 100 mm, k2 = 0.72 W/(m·K)A = 12 m²T1 = 17 °CT3 = -2 °C
Ti = °C
4.Medium
Wood, k = 0.1750 mmExpanded polystyrene, k = 0.03525 mm20 °C-12 °CQ̇ = ?

A wall is made of 50 mm of wood and 25 mm of expanded polystyrene, with an area of 15 m². The outer faces are at 20 °C and -12 °C. Find the heat flow Q̇ through the wall.

L1 = 50 mm, k1 = 0.17 W/(m·K)L2 = 25 mm, k2 = 0.035 W/(m·K)A = 15 m²T1 = 20 °CT3 = -12 °C
Q̇ = W
5.Hard
Expanded polystyrene, k = 0.035200 mmGlass, k = 0.9625 mmroom 20 °Coutside 1 °CTs​ = ?Q̇

A wall of 200 mm expanded polystyrene and 25 mm glass separates a room at 20 °C from outside air at 1 °C. The convection coefficients are 10 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 = 200 mm, k1 = 0.035 W/(m·K)L2 = 25 mm, k2 = 0.96 W/(m·K)A = 10 m²hi = 10 W/(m²·K)ho = 20 W/(m²·K)Troom = 20 °CTout = 1 °C
Ts = °C
6.Hard
Gypsum board, k = 0.17250 mmBrick, k = 0.72150 mmroom 20 °Coutside 0 °CQ̇ = ?

A wall of 250 mm gypsum board and 150 mm brick separates a room at 20 °C from outside air at 0 °C. The convection coefficients are 8 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 4 m². Find the heat loss Q̇ through the wall.

L1 = 250 mm, k1 = 0.17 W/(m·K)L2 = 150 mm, k2 = 0.72 W/(m·K)A = 4 m²hi = 8 W/(m²·K)ho = 25 W/(m²·K)Troom = 20 °CTout = 0 °C
Q̇ = W

Answer key

  1. 1. q″ = 76.8 W/m²
  2. 2. q″ = 336 W/m²
  3. 3. Ti = 4.609 °C
  4. 4. Q̇ = 476 W
  5. 5. Ts = 19.68 °C
  6. 6. Q̇ = 43.39 W

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