Very old thread!
My 2x6 arch's firebox is only 18 inches deep, but almost 24 inches wide. This means most wood gets added at an angle, because a good amount of it is longer than 18 inches. It makes quick loading difficult at times. If a chunk gets hung up, the door will not close. When it's up to running temperature, you can not reach in there and move things around. So, after the season I will probably extent the firebox another 6 inches inside. The smaller firebox may also limit the intensity of the boil, particularly toward the rear of the flue section. I just can't get enough wood in there.
Also, don't leave out your AOF/AUF. I did, and ended up adding it before the second season. Much easier to do it the first time. Refer to the UVM paper on combustion efficiency.
I'm a home built guy, but I have to say that next time I may buy the matching arch for my pans. The manufacturer has the experience to "build a better mousetrap", and all you have to do then is boil sap, not study thermodynamics. We may save money on the build, but if we guess wrong on some design details, we will pay every time we boil.
Last edited by Ghs57; 03-12-2017 at 06:14 PM.
Reason: Just noticed this tread is from 2013
Gary / Zena Crossroads / 42˚ 00' 24" N / Hobby in Early '70s, Addiction since 2014
175+ taps on 3/16 (60 of which are on two Lunchbox Vac/Releasers)
12x34 timber framed sap house w/attached 10x34 shed roof for storage
2 x 6 Smoky Lake hybrid pan on Corsair arch with AUF/steam hood/preheater/concentric exhaust
7.0 KW Sun Power PV System, Smokey Lake Filter Press/Steam Bottler, Modified NGMP RO - 2 4x40 posts 200 gph