Make a cupola, that is by far the best way to vent all of the steam generated boiling sap into syrup. The only other good way is to have hoods on the pan and vent the steam thru steam stacks. Even a 2x5 flat pan, when you get boiling properly will fog the shack if you don't have a cupola. In fact, do you think you might someday grow into a 2x6 evaporator with 2 pans? If yes, make a 2x6 cupola now.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.