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 = 0.9610 mm24 °C5 °Cq″ = ?

A wall of glass is 10 mm thick and has an area of 8 m². Its faces are held at 24 °C and 5 °C. Find the heat flux q″ through the wall.

k = 0.96 W/(m·K)L = 10 mmA = 8 m²T1 = 24 °CT2 = 5 °C
q″ = W/m²
2.Easy
Concrete, k = 1.4200 mm25 °C5 °Cq″ = ?

A wall of concrete is 200 mm thick and has an area of 8 m². Its faces are held at 25 °C and 5 °C. Find the heat flux q″ through the wall.

k = 1.4 W/(m·K)L = 200 mmA = 8 m²T1 = 25 °CT2 = 5 °C
q″ = W/m²
3.Medium
Wood, k = 0.17250 mmMineral wool, k = 0.04150 mm19 °C7 °CQ̇ = ?

A wall is made of 250 mm of wood and 150 mm of mineral wool, with an area of 12 m². The outer faces are at 19 °C and 7 °C. Find the heat flow Q̇ through the wall.

L1 = 250 mm, k1 = 0.17 W/(m·K)L2 = 150 mm, k2 = 0.04 W/(m·K)A = 12 m²T1 = 19 °CT3 = 7 °C
Q̇ = W
4.Medium
Mineral wool, k = 0.04250 mmConcrete, k = 1.450 mm23 °C-2 °CQ̇ = ?

A wall is made of 250 mm of mineral wool and 50 mm of concrete, with an area of 8 m². The outer faces are at 23 °C and -2 °C. Find the heat flow Q̇ through the wall.

L1 = 250 mm, k1 = 0.04 W/(m·K)L2 = 50 mm, k2 = 1.4 W/(m·K)A = 8 m²T1 = 23 °CT3 = -2 °C
Q̇ = W
5.Hard
Wood, k = 0.17250 mmExpanded polystyrene, k = 0.035100 mmroom 21 °Coutside -7 °CQ̇ = ?

A wall of 250 mm wood and 100 mm expanded polystyrene separates a room at 21 °C from outside air at -7 °C. The convection coefficients are 8 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 = 100 mm, k2 = 0.035 W/(m·K)A = 6 m²hi = 8 W/(m²·K)ho = 30 W/(m²·K)Troom = 21 °CTout = -7 °C
Q̇ = W
6.Hard
Mineral wool, k = 0.0450 mmGlass, k = 0.96150 mmroom 21 °Coutside -3 °CTs​ = ?Q̇

A wall of 50 mm mineral wool and 150 mm glass separates a room at 21 °C from outside air at -3 °C. The convection coefficients are 6 W/(m²·K) inside and 30 W/(m²·K) outside, and the wall area is 4 m². Find the temperature Ts of the inside surface of the wall.

L1 = 50 mm, k1 = 0.04 W/(m·K)L2 = 150 mm, k2 = 0.96 W/(m·K)A = 4 m²hi = 6 W/(m²·K)ho = 30 W/(m²·K)Troom = 21 °CTout = -3 °C
Ts = °C

Answer key

  1. 1. q″ = 1824 W/m²
  2. 2. q″ = 140 W/m²
  3. 3. Q̇ = 27.58 W
  4. 4. Q̇ = 31.82 W
  5. 5. Q̇ = 37.45 W
  6. 6. Ts = 18.51 °C

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