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.

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1.Easy
Mineral wool, k = 0.0420 mm22 °C5 °CQ̇ = ?

A wall of mineral wool is 20 mm thick and has an area of 20 m². Its faces are held at 22 °C and 5 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.04 W/(m·K)L = 20 mmA = 20 m²T1 = 22 °CT2 = 5 °C
Q̇ = W
2.Easy
Mineral wool, k = 0.04250 mm21 °C6 °CQ̇ = ?

A wall of mineral wool is 250 mm thick and has an area of 12 m². Its faces are held at 21 °C and 6 °C. Find the rate of heat conduction Q̇ through the wall.

k = 0.04 W/(m·K)L = 250 mmA = 12 m²T1 = 21 °CT2 = 6 °C
Q̇ = W
3.Medium
Expanded polystyrene, k = 0.035250 mmGypsum board, k = 0.17150 mm20 °C-12 °CTi​ = ?Q̇

A wall is made of 250 mm of expanded polystyrene and 150 mm of gypsum board, with an area of 15 m². The outer faces are at 20 °C and -12 °C. Find the temperature Ti at the interface between the two layers.

L1 = 250 mm, k1 = 0.035 W/(m·K)L2 = 150 mm, k2 = 0.17 W/(m·K)A = 15 m²T1 = 20 °CT3 = -12 °C
Ti = °C
4.Medium
Gypsum board, k = 0.17200 mmWood, k = 0.1725 mm22 °C10 °CQ̇ = ?

A wall is made of 200 mm of gypsum board and 25 mm of wood, with an area of 20 m². The outer faces are at 22 °C and 10 °C. Find the heat flow Q̇ through the wall.

L1 = 200 mm, k1 = 0.17 W/(m·K)L2 = 25 mm, k2 = 0.17 W/(m·K)A = 20 m²T1 = 22 °CT3 = 10 °C
Q̇ = W
5.Hard
Mineral wool, k = 0.0450 mmGlass, k = 0.9625 mmroom 21 °Coutside 2 °CQ̇ = ?

A wall of 50 mm mineral wool and 25 mm glass separates a room at 21 °C from outside air at 2 °C. The convection coefficients are 6 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 6 m². Find the heat loss Q̇ through the wall.

L1 = 50 mm, k1 = 0.04 W/(m·K)L2 = 25 mm, k2 = 0.96 W/(m·K)A = 6 m²hi = 6 W/(m²·K)ho = 25 W/(m²·K)Troom = 21 °CTout = 2 °C
Q̇ = W
6.Hard
Mineral wool, k = 0.04100 mmConcrete, k = 1.4150 mmroom 20 °Coutside -13 °CQ̇ = ?

A wall of 100 mm mineral wool and 150 mm concrete separates a room at 20 °C from outside air at -13 °C. The convection coefficients are 7.7 W/(m²·K) inside and 25 W/(m²·K) outside, and the wall area is 12 m². Find the heat loss Q̇ through the wall.

L1 = 100 mm, k1 = 0.04 W/(m·K)L2 = 150 mm, k2 = 1.4 W/(m·K)A = 12 m²hi = 7.7 W/(m²·K)ho = 25 W/(m²·K)Troom = 20 °CTout = -13 °C
Q̇ = W

Answer key

  1. 1. Q̇ = 680 W
  2. 2. Q̇ = 28.8 W
  3. 3. Ti = −8.482 °C
  4. 4. Q̇ = 181.3 W
  5. 5. Q̇ = 76.89 W
  6. 6. Q̇ = 142.6 W

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