I'm not sure who told you drop flues needed to be drained to protect from freezing. That is not true. If you have boiled at least 3 hours at full boil, the pans are sweet enough to not freeze down to about 10F, if going colder than that you can either drain or put a 50+ watt incandescent light in the firebox, that will give off enough heat to protect it to somewhere about 20-25 below 0. in maple season I've never heard of temps that cold. Just leave the pans, the sweet might slush on the top, but it will not freeze solid. I never spread my boils out, if I had enough sap to boil at least an hour I boiled. I did far prefer 3 hrs or more however. Once you have sweetened the pans, as long as you have not pulled all of the contents off, you no longer need a 3 hr boil. (the advantage of continuous flow)
I just find I prefer raised flue but whatever your preference, go with it. As for doing 6 boils a season, I'm no help. How was the size of the sugarhouse you had, was it big enough, or bigger than you needed? Just go by how it was for you. If the boil took too long, go 1 size bigger on the evaporator.
Last edited by maple flats; 03-12-2024 at 08:21 PM.
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.