Question

The radiant energy incident on the earth's surface on a sunny day is roughly 900.0 W/m².

Collecting and focusing sunlight and using the focused beam to heat a fluid is an old idea, and as the environmental costs of fossil-fuel combustion mount, solar heating becomes an increasingly attractive alternative.

Suppose a house is to be designed that will have a circulating forced-air central-heating unit, and solar energy is contemplated as a heat source (backed up with a conventional furnace to be used on cloudy days).

If air is to be fed at a rate of 1000.0 m³/min at 25.0°C and 1 atm, and the air is to be heated to 60.0°C before being discharged into the living space, what is the required area of the solar collector plates?

Assume 30.0% of the radiant energy incident on the plates is used to heat the air.

Answer 1