How much surface area do you gain with two reflectors?

-With no reflectors on our box, the glass surface area that radiation can penetrate is 12.5" x 12.5" = 156.25 sq. inches.

-Adding two 8" x  11.5" reflectors on the box, increases the amount of solar radiation entering the box.  With reflectors, the surface area that radiation can penetrate is equivalent to having a 248.25 sq. inches piece of glass.

-To determine the amount of gain in surface area with reflectors the adjcent length (shown in the diagram below) needs to be determined.  The adjcent length is also our reflectors´ shadows when the sun is directly above. 

-To find the adjcent length use:

-Multiple the Adj length by the length of the reflector

(4" * 11.5" = 46 sq, inches) 

-Multiple 46 sq. inches by 2 since there are two reflectors = 92 sq. inches.

-The total surface area for solar radiation to penetrate the box is...

92 sq. inches + 156.25 sq. inches = 248.25 sq. inches

-Increasing the surface area, increases the amount of solar radiation entering.

The equation below determines the amount of radiation entering our cooker.

 q insol = Insol max * Area *  Temp Change * Efficiency

We were curious as to how much power we were recieving from the sun per hour, as you know power = energy /time.  To do this we had to use the following equation:

Q insol = Insol max * Area

Q insol = (317 btu/hr*ft sq.) * (ft sq./144 in. sq.) * (248.25 in sq.)

Q insol = 546.2 btu/hr