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
Concrete, k = 1.410 mm19 °C-10 °Cq″ = ?

A wall of concrete is 10 mm thick and has an area of 20 m². Its faces are held at 19 °C and -10 °C. Find the heat flux q″ through the wall.

k = 1.4 W/(m·K)L = 10 mmA = 20 m²T1 = 19 °CT2 = -10 °C
q″ = W/m²
2.Easy
Glass, k = 0.96250 mm16 °C-15 °Cq″ = ?

A wall of glass is 250 mm thick and has an area of 6 m². Its faces are held at 16 °C and -15 °C. Find the heat flux q″ through the wall.

k = 0.96 W/(m·K)L = 250 mmA = 6 m²T1 = 16 °CT2 = -15 °C
q″ = W/m²
3.Medium
Mineral wool, k = 0.04150 mmConcrete, k = 1.4100 mm17 °C-3 °CTi​ = ?Q̇

A wall is made of 150 mm of mineral wool and 100 mm of concrete, with an area of 6 m². The outer faces are at 17 °C and -3 °C. Find the temperature Ti at the interface between the two layers.

L1 = 150 mm, k1 = 0.04 W/(m·K)L2 = 100 mm, k2 = 1.4 W/(m·K)A = 6 m²T1 = 17 °CT3 = -3 °C
Ti = °C
4.Medium
Mineral wool, k = 0.04100 mmGlass, k = 0.96100 mm21 °C6 °CTi​ = ?Q̇

A wall is made of 100 mm of mineral wool and 100 mm of glass, with an area of 4 m². The outer faces are at 21 °C and 6 °C. Find the temperature Ti at the interface between the two layers.

L1 = 100 mm, k1 = 0.04 W/(m·K)L2 = 100 mm, k2 = 0.96 W/(m·K)A = 4 m²T1 = 21 °CT3 = 6 °C
Ti = °C
5.Hard
Concrete, k = 1.4250 mmGlass, k = 0.96150 mmroom 21 °Coutside -6 °CTs​ = ?Q̇

A wall of 250 mm concrete and 150 mm glass separates a room at 21 °C from outside air at -6 °C. The convection coefficients are 8 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 8 m². Find the temperature Ts of the inside surface of the wall.

L1 = 250 mm, k1 = 1.4 W/(m·K)L2 = 150 mm, k2 = 0.96 W/(m·K)A = 8 m²hi = 8 W/(m²·K)ho = 20 W/(m²·K)Troom = 21 °CTout = -6 °C
Ts = °C
6.Hard
Concrete, k = 1.4250 mmExpanded polystyrene, k = 0.03550 mmroom 21 °Coutside -12 °CQ̇

A wall of 250 mm concrete and 50 mm expanded polystyrene separates a room at 21 °C from outside air at -12 °C. The convection coefficients are 6 W/(m²·K) inside and 20 W/(m²·K) outside, and the wall area is 4 m². Find the overall heat transfer coefficient U of the wall.

L1 = 250 mm, k1 = 1.4 W/(m·K)L2 = 50 mm, k2 = 0.035 W/(m·K)A = 4 m²hi = 6 W/(m²·K)ho = 20 W/(m²·K)Troom = 21 °CTout = -12 °C
U = W/(m²·K)

Answer key

  1. 1. q″ = 4060 W/m²
  2. 2. q″ = 119 W/m²
  3. 3. Ti = −2.626 °C
  4. 4. Ti = 6.6 °C
  5. 5. Ts = 14.38 °C
  6. 6. U = 0.5483 W/(m²·K)

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