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 = 0.035150 mm25 °C-15 °Cq″ = ?

A wall of expanded polystyrene is 150 mm thick and has an area of 4 m². Its faces are held at 25 °C and -15 °C. Find the heat flux q″ through the wall.

k = 0.035 W/(m·K)L = 150 mmA = 4 m²T1 = 25 °CT2 = -15 °C
q″ = W/m²
2.Easy
Gypsum board, k = 0.1750 mm24 °C1 °CQ̇ = ?

A wall of gypsum board is 50 mm thick and has an area of 12 m². Its faces are held at 24 °C and 1 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.17 W/(m·K)L = 50 mmA = 12 m²T1 = 24 °CT2 = 1 °C
Q̇ = W
3.Medium
Mineral wool, k = 0.04250 mmBrick, k = 0.72150 mm22 °C-4 °CTi​ = ?Q̇

A wall is made of 250 mm of mineral wool and 150 mm of brick, with an area of 10 m². The outer faces are at 22 °C and -4 °C. Find the temperature Ti at the interface between the two layers.

L1 = 250 mm, k1 = 0.04 W/(m·K)L2 = 150 mm, k2 = 0.72 W/(m·K)A = 10 m²T1 = 22 °CT3 = -4 °C
Ti = °C
4.Medium
Wood, k = 0.17200 mmExpanded polystyrene, k = 0.03525 mm25 °C3 °CQ̇ = ?

A wall is made of 200 mm of wood and 25 mm of expanded polystyrene, with an area of 15 m². The outer faces are at 25 °C and 3 °C. Find the heat flow Q̇ through the wall.

L1 = 200 mm, k1 = 0.17 W/(m·K)L2 = 25 mm, k2 = 0.035 W/(m·K)A = 15 m²T1 = 25 °CT3 = 3 °C
Q̇ = W
5.Hard
Brick, k = 0.72250 mmExpanded polystyrene, k = 0.03525 mmroom 22 °Coutside -3 °CQ̇ = ?

A wall of 250 mm brick and 25 mm expanded polystyrene separates a room at 22 °C from outside air at -3 °C. The convection coefficients are 8 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 8 m². Find the heat loss Q̇ through the wall.

L1 = 250 mm, k1 = 0.72 W/(m·K)L2 = 25 mm, k2 = 0.035 W/(m·K)A = 8 m²hi = 8 W/(m²·K)ho = 25 W/(m²·K)Troom = 22 °CTout = -3 °C
Q̇ = W
6.Hard
Mineral wool, k = 0.04100 mmBrick, k = 0.7250 mmroom 21 °Coutside 3 °CQ̇

A wall of 100 mm mineral wool and 50 mm brick separates a room at 21 °C from outside air at 3 °C. The convection coefficients are 7.7 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 = 100 mm, k1 = 0.04 W/(m·K)L2 = 50 mm, k2 = 0.72 W/(m·K)A = 20 m²hi = 7.7 W/(m²·K)ho = 25 W/(m²·K)Troom = 21 °CTout = 3 °C
U = W/(m²·K)

Answer key

  1. 1. q″ = 9.333 W/m²
  2. 2. Q̇ = 938.4 W
  3. 3. Ti = −3.161 °C
  4. 4. Q̇ = 174.5 W
  5. 5. Q̇ = 163.1 W
  6. 6. U = 0.3651 W/(m²·K)

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