More thoughts on efficiency...

[TheNamelessPoet]

My setup is inefficient just based on the nature of propane itself... BUT...

I know covering the pan is working against yourself because the boil is harder, but the evaporated water just runs right back into the sides correct? What about a cover that is above the pan and the sides extended 2+ inches below the rim of the pan and 2 inches below the rim? It would need to be angled like the pitch on a house and also have a slight grade from one end to the other to try and have as much water run down the peak to the lower end past the edge of the pan.

Any reason that would not work?

[maple flats]

Any cover designed to move the condensation away from the pan is good. Just make sure it's made of an appropriate material. Heck, I was on a maple tour maybe 15 years ago. At one sugarhouse one wall was covered with blue and red ribbons from the state fair. The evaporator was a 4x12 or 4x14' and the hood was made of wooden 1x3's and clear poly was attached to it. It was out about 6" past the edges of the pans and hung about 6" below the top of the pans. From there it was attached to the sides of the cupola.
Whatever works, as long as it's safe and clean.