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
Mineral wool, k = 0.0450 mm16 °C9 °Cq″ = ?

A wall of mineral wool is 50 mm thick and has an area of 8 m². Its faces are held at 16 °C and 9 °C. Find the heat flux q″ through the wall.

k = 0.04 W/(m·K)L = 50 mmA = 8 m²T1 = 16 °CT2 = 9 °C
q″ = W/m²
2.Easy
Wood, k = 0.17150 mm22 °C3 °CQ̇ = ?

A wall of wood is 150 mm thick and has an area of 10 m². Its faces are held at 22 °C and 3 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.17 W/(m·K)L = 150 mmA = 10 m²T1 = 22 °CT2 = 3 °C
Q̇ = W
3.Medium
Glass, k = 0.96200 mmWood, k = 0.1725 mm22 °C-12 °CQ̇ = ?

A wall is made of 200 mm of glass and 25 mm of wood, with an area of 20 m². The outer faces are at 22 °C and -12 °C. Find the heat flow Q̇ through the wall.

L1 = 200 mm, k1 = 0.96 W/(m·K)L2 = 25 mm, k2 = 0.17 W/(m·K)A = 20 m²T1 = 22 °CT3 = -12 °C
Q̇ = W
4.Medium
Glass, k = 0.96100 mmWood, k = 0.17150 mm25 °C-8 °CTi​ = ?Q̇

A wall is made of 100 mm of glass and 150 mm of wood, with an area of 12 m². The outer faces are at 25 °C and -8 °C. Find the temperature Ti at the interface between the two layers.

L1 = 100 mm, k1 = 0.96 W/(m·K)L2 = 150 mm, k2 = 0.17 W/(m·K)A = 12 m²T1 = 25 °CT3 = -8 °C
Ti = °C
5.Hard
Gypsum board, k = 0.17250 mmBrick, k = 0.72150 mmroom 22 °Coutside -4 °CQ̇ = ?

A wall of 250 mm gypsum board and 150 mm brick separates a room at 22 °C from outside air at -4 °C. The convection coefficients are 6 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 6 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 = 6 m²hi = 6 W/(m²·K)ho = 30 W/(m²·K)Troom = 22 °CTout = -4 °C
Q̇ = W
6.Hard
Mineral wool, k = 0.04100 mmExpanded polystyrene, k = 0.03525 mmroom 20 °Coutside -6 °CQ̇

A wall of 100 mm mineral wool and 25 mm expanded polystyrene 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 10 m². Find the overall heat transfer coefficient U of the wall.

L1 = 100 mm, k1 = 0.04 W/(m·K)L2 = 25 mm, k2 = 0.035 W/(m·K)A = 10 m²hi = 6 W/(m²·K)ho = 20 W/(m²·K)Troom = 20 °CTout = -6 °C
U = W/(m²·K)

Answer key

  1. 1. q″ = 5.6 W/m²
  2. 2. Q̇ = 215.3 W
  3. 3. Q̇ = 1913 W
  4. 4. Ti = 21.52 °C
  5. 5. Q̇ = 83.03 W
  6. 6. U = 0.2915 W/(m²·K)

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