Given:

Thermal conductivity of insulation is 0.029 W/m⋅K .

Thickness of Sheet is 20 mm .

Temperature difference through sheet is 10°C .

Dimension of sheet is 2 m×2 m .

Concept used:

Write the expression for heat flux passing through the sheet of insulation.

  QA=kΔTΔx ........ (1)

Here, Q is the rate of heat transfer, A is the cross-sectional area of sheet, k is thermal conductivity of specimen, ΔT is the temperature difference through the sheet and  Δx is the thickness of sheet.

Calculation:

Substitute 10°C for ΔT , 0.029 W/m⋅K for k and 20 mm for Δx in equation (1).

  QA=(0.029)10( 20 mm( 1 m 1000 mm ))=14.5 W/m2

Conclusion:

Thus, heat Flux through a Sheet of insulation of dimension 2 m×2 m is 14.5 W/m2 .

Concept used:

Calculate the area of rectangular sheet as follows:

  A=2 m×2 m=4 m2

Write the expression for rate of heat transfer.

  Q=kAΔTΔx ........ (2)

Calculation:

Substitute 10°C for ΔT , 0.029 W/m⋅K for k , 4 m2 for A and 20 mm for Δx in equation (1).

  Q=(4)(0.029)10( 20 mm( 1 m 1000 mm ))=58 W

Conclusion:

Thus, rate of heat transfer through sheet of insulation is 58 W .