increase steam ventilation through cupola?

[BSD]

Looking at the picture, if your stack is 10-12" the cupola doors appear to be not much taller -or maybe even shorter than 10". My guess is that for your 2.5 x 10 arch you need more open space up there. Also the vent in the gable end is just drawing cold air in and not helping you at all.

that's the problem, the windows are just too small (look nice though! but that doesn't help me).

I'll try covering up the vent on the gable end, but i don't think it's going to do much. the double doors are wide open (didn't get a chance to hang them yet). do you think there is too much cooling coming in through the front door? i've been trying to get my buddy back over to hang them for me, but favors only go so far.

at this point my options are remove the windows and frame a bigger opening. or build a steam hood i believe.

[johnallin]

the double doors are wide open (didn't get a chance to hang them yet).

Forget about the vent and the size of your cupola openings until you run it with the doorway covered over. You may as well be outside - I don't think your cupola is doing anything for you at this point.

[Woody77]

First time boiling in a shack this year and have a 4x8 cupola, it has flip-out windows in place of the normal cupola doors. and I suspect they're framed in a way that is reducing the size of the openings.
I'm getting good amount out the windows but typically have a vapor level about 80" off the ground (height of the big door in the front). After boiling for a few hours, the roof gets saturated and then it starts raining inside. I can't keep doing this or i'll rot the building from the inside out.

is there a formula to determine the CFM of steam generated by boiling sap?
is there a good way to get a fan up in the cupola to boost ventilation? or am I better off building a hood and steam vent?

this was taken on a crystal clear, low humidity night, only boiling around 40-45gph
Attachment 17643

This was last night when the humidity was sky-high.Visibility was realistically 36", and the cloud level was only 30-36" off the ground. It was a disaster. i thought i was going to have to shut down because it was so bad, couldn't see in the pans, and almost had a foam over in one of the channels. was boiling 45gph last night. this was before it "got bad".
Attachment 17644.

Once the front moved through, i was able to get back to "normal" like the first picture. but cannot continue long term obviously. I need to get it resolved before i can go any faster in my pans. as i'd like to be up around 60-70 gph?

A heat source will solve this problem we use either our gas stove or a construction style propane heater it goes away almost instantly. And drys the surfaces a bit.

[MISugarDaddy]

We built our sugarhouse in 2013 and have tried every idea suggested here. We have a 3' by 6' cupola, and with our previous 2' x 4' evaporator it was quite bad during a boil, but still manageable. When we went to the 2' x 6' evaporator we went with a hood immediately that we piped up into the cupola, thinking that the steam wouldn't be a problem since it was already piped up into the cupola, wrong. Finally after experimenting with different ideas which didn't solve the problem, we finally put the vent pipe from the hood through the roof of the cupola and the steam problem has now been solved. We hated to cut another hole through the roof, but it has worked great.
Gary

[maple flats]

My steam stacks end in the cupola, on my 3x8 hoods I have 2 steam stacks of 15" each, about half way up to the cupola, then I have a 13" suspended from the cupola down into the 15" ones. My hood over the syrup pan is about 14-16" above the pan and is the same 3x3 as the pan. At my usual boil rate of 75 gph and my highest rate of 81gph I get less steam that what the picture in Reply #9 by sugarmaker shows. My cupola is only 12 SF and it has 2 doors on each side that are 19"x32" each. Rarely but in some weather patterns I only open the doors on one side, but I still get no steam issues. The only time I had issues with steam was the one season I had no hood and even then the steam level was at about 7-7.5' up, the problem was the raining in there. A hood fixed that.

[BSD]

the plan right now is to replace my current arch/evaporator next season, and when i upgrade i will be incorporating a hood and pre-heater into the decision, it will go through the roof. i'm done playing with the cupola. I had another boil yesterday like the one i posted previously. after 3 hours it was flat-out raining in the building from the condensation. I did hit a personal best, sustained 72 GPH on my arch at least.

[TapTapTap]

I'm very proud of the cupola on our new sugarhouse. It works great even without a hood over our 30"x10' Leader Vortex Arch and raised flue rear pan. Lots of steam that flows nicely out the top and almost no rain! My secret is the 12:12 pitch roof, about 10 ft walls, T&G wood lining against the metal roof (not quite complete), and four 54"x32" doors. A little side ventilation from the windows helps the draft.
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