Steam Hood Height Question

[TedA]

This summer I built a sugar shack so we could move our cooking operation indoors. I decided to go with a steam hood rather than a cupola to handle the evaporating steam. This last weekend, I put up the steam hood - suspended over my 2x4 hybrid hobby drop flue pan. The steam hood is 3x5 to allow some overlap of the pan on all sides. As it turned out, I have very little room in back before bumping up against the stack for the arch. So, most of the extra length (about 10 inches) is over the front of the evaporator pan. This looks like it will be a constant head bumper every time we fuel the arch unless the hood is mounted/suspended above normal head height - which for me is 70 inches off the floor and up to 76 inches for my kids. Has anyone else had this problem? I went ahead and suspended the hood so now the bottom is about 74 inches off the floor. My arch is about 38 inches tall and the pan adds another 10 inches. That leaves me with a 26 inch gap between the bottom of the steam hood and the top of the evaporator pan. For those who have suspended steam hoods, do you think I will catch most of the steam with this much gap? Or will I need to shorten the gap? If I need to shorten the gap, by how much? At this point, both stacks (arch and steam) are through the roof, finished off with rain caps, storm collars and sealed with caulk so adjusting either stack (i.e. raising the arch up or lowering the steam hood) will not be easy. Any advice would be helpful. Picture attached.12050

[maple flats]

While I'm not in the same boat as you are, you may want to try the way I did my hood.
On my 3x8 evaporator I have an undersized cupola, it was designed for a 2x6 and never got enlarged when I changed to a 3x8. My hood (2 sections bolted together, a 3x5 flue pan hood rests on the flue pan and is about 18" tall to the steam stack outlet and a syrup pan hood that is even with the top of the back hood, but is only about 12" tall). While this sounds like I only have 6" clearance over the syrup pan, it is far grater. I have a raised flue evaporator, the syrup pan is 14" tall and the flue pan is 24" tall, (it sets up 10" taller than the syrup pan). Now I have 10" + 6" = 16" space.
My steam stacks (I have 2 @ 15" diameter each) go up 6' (of 15" stack), then my upper stack is 13" and it is suspended in the cupola, the top opening is roughly even with the bottom of the cupola doors when they are open. Next I have a winch set up on an outer wall of the sugar house and it lifts the whole hood assembly along with the 2 stacks of 15" diameter. As it rises the 15" telescopes over the suspended 13" stacks. When the evaporator is boiling, I get some, but very little steam leaking where the 15" is over the 13" stack. Since the stack is hot, it creates a good draft and draws almost all of the steam into the 13" stack.
I would think you could do something similar, if you try it, leave the current stack thru the roof and make sure it is screwed together and supported well. Then attach about 4' of a stack (you can use an reducer to attach it to the existing take off on the hood, and enlarge the 4' long section 2" in diameter. (when done the lower should be 8-10" overlap over the smaller diameter upper stack).
Now you need 4 pulleys, each must be attached directly above the attachment point on the hood, once thru the pulleys run all 4 to attach to a winch cable. Since everything is light, you can use a small boat winch like I did, or yours will likely be light enough to pull on a rope, light chain or cable by hand. Then set the length to hold the hood at the lower height, and have a system to raise it to hold it up for fueling.
If I've confused this, just ask for clarification. Unfortunately I do not have pics of it.
I suggest you allow 14-16" over the pan when down and at least 75" off the floor when up. I have a light weight turnbuckle at each (of 6) attachment points on the hood for fine tuning the level, when I lower the hood all 4 corners of the flue hood make contact on the flue pan at the same time.

[n8hutch]

I had a similar setup last year, I found that my hood was no deep enough & the steam would bounce off it & roll out the sides, I ended up adding a 8" extension to the sides & that was pretty effective, I can measure when I get home & let you know the distance from pan to hood.