Question

A temperature difference of 85◦C is impressed across a fiberglass layer of 13 cm thickness. The
thermal conductivity of the fiberglass is 0.035 W/m◦C. Compute the heat transferred through
the material per hour per unit area.

Answer 1

Answer:

Formula of heat transfer per sec per unit area is H=\frac{K\Delta{T}}{\Delta{x}}H=

Δx

KΔT

Where K is thermal conductivity

∆T is the change in temperature

∆x is the thickness of layer.

Here, K = 0.035 w/m.°C

∆T = 85°C

∆x = 13 cm = 0.13 m

Now, Heat per sec per unit area = 0.035 × 85/0.13 = 22.88 J

so, heat transfer per unit hour per unit area = 3600 × 22.88 J = 82384.6 J