A1500 w portable heater is needed to replace the heat lost through a circular window (radius 25 cm) in the wall of a home that is made of a single pane of glass 0.30 cm thick. thermal conductivity for the glass is 0.63 w/mk. the temperature inside the house is 20°c and outside is -12°c. what is the thickness of the window?

The thickness of the window pane is 2.94 mm

Solution:

As per the question:

Power of the heater, P = 1500 W

Thickness of the glass pane, t = 0.30 cm =

Radius, R = 25 cm = 0.25 m

Thermal Conductivity of glass, K = 0.63 W/ mK

Inside Temperature,

Outside Temperature,

Now,

Power of the heater = Heat Loss, Q

Thus

Q = 1500 W

We know that:

t' = 2.94 mm