A simple solar heater consists of a flat plate of glass below which is located a shallow pan filled with water, so that the water is in contact with the glass plate above it. Solar radiation passes...

A simple solar heater consists of a flat plate of glass

below which is located a shallow pan filled with water, so

that the water is in contact with the glass plate above it.

Solar radiation passes through the glass at the rate of

156 Btu/h ft2

. The water is at 200°F and the surrounding

air is at 80°F. If the heat transfer coefficients between the

water and the glass, and between the glass and the air are

5 Btu/h ft2 °F and 1.2 Btu/h ft2 °F, respectively, determine the time required to transfer 100 Btu per square foot

of surface to the water in the pan. The lower surface of

the pan can be assumed to be insulated.