+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: increase steam ventilation through cupola?

  1. #1
    Join Date
    Jan 2017
    Location
    Danbury, Connecticut
    Posts
    331

    Default increase steam ventilation through cupola?

    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
    20180212_204642.jpg

    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".
    20180216_180019.jpg.

    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?
    Last edited by BSD; 02-17-2018 at 09:55 AM.
    2016 - 36 Taps - File Cabinet Arch + Food Pans
    2017 - 2.5'x10' drop flues - 3/16 Natural Vacuum - 122 Taps
    2018 - 16x20 Sugar Shack - 3/16 Natural Vacuum - 235 Taps

  2. #2
    Join Date
    Mar 2013
    Location
    Grawn Michigan
    Posts
    199

    Default

    I have window's built into either side of my Sugar Shack that I can open to improve air flow and help get the steam rising out the cupola better. When it get't real bad I just open the door. I am looking into engineering a venthood however to really push all that steam out of the shack.received_1869560749781232.jpg

    Latitude:N 44° 50' 25.0463"
    Longitude:W 85° 38' 57.8906"

    New for 2022 (My 10th year) a 9" CDL Vacuum Filter Press
    2016/2017 12' X 16' Sugar Shack 6/12 pitch roof W/ 3' X 4' Cupola.
    John Deere HPX 4X4 Gator (Pop's left it to me when he died)
    New for 2020 HB10 RO In A Bucket, a game changer.
    2015 Purchased 50 used Bag holders.
    2016 Purchased a home made evaporator and "everything" that went with it.
    20 acre Sugar Bush

  3. #3
    Join Date
    Jan 2006
    Location
    Oneida NY
    Posts
    11,547

    Default

    I had very similar until I made a hood. My hood was made out of aluminum flashing and pop riveted together. I bent it on a trim brake, but back when I was in the heating business at times I bent sheet metal (stiffer than aluminum) using 3 pieces of 2x4, 2 to clamp the sheet at the spot I wanted to bend it, and a third to bend it. My hood on my 2x6 took about 90 minutes to shape and then maybe an hour to pop rivet together, drilling each hole one at a time, riveting it then doing the next. I formed a gutter on the inside edge and at the corners I used silicone caulk to seal it. I then had a small fitting for a drain to a hose, it was just a male adapter but I used a nut on each side and sealed it with silicone. On a larger hood for my 3x8 I made it out of heavier sheet aluminum and used 1x1x1 channel for the gutter. If I were doing that again I'd get 1.5 x 1.5 x 1.5 channel.
    On all of my hoods including my current manufactured hood with 2 @15" steam stacks, I have aluminum stack suspended from a SS rod in the cupola and it hangs down into the stack coming up. My current on is 13" hanging into the 15" stacks. Even with it like that I get no buildup of steam in the sugarhouse, even when there is a heavy fog outside and I get almost no dripping off the underside of the steel roofing. From time to time I can see a drip where it hit the floor but it's near zero drips.
    I have the telescoping method because it allows me to hoist the hood by cranking on a small boat winch and the suspended stack simply allows the bigger stack to go up without any problems.
    My cupola on my 3x8 boiling about 75-85 GPH is thus venting into and out of the cupola which is only 2' across by 6' long and which has a flip down door of 4'6" x 16" on each side. Even when I get a funky breeze and can only open one side it vents perfectly.
    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.

  4. #4
    Haynes Forest Products Guest

    Default

    Been there done that. Having to many windows and doors open allows the hot water vapor and the cold outside air to mix and wreak havoc on the place. I remember being in a shack that had so much fog you had to write your name one the toe of your boots to know who you were talking to.

    Had a buddy with same problem and we did a quick extension down to the evap. Got some white board adout 1/8 3/16 thick 4 sheets and some 2" X 2" framing. We brought the cupola opening down 4 ft. Make it 4x12 or so don't get fancy. The other thing is try and get your make up air to NOT come in and blast into the cloud of steam. It will swirl around cooling it off causing it to drop and hover. You need to grin and bare it at start up to get the shack warm and get the Convection Current working for you. Without a hood you will have a tricky balance between hot and cold air and water vapor.
    Last edited by Haynes Forest Products; 02-17-2018 at 12:19 PM.

  5. #5
    Join Date
    Jan 2017
    Location
    Danbury, Connecticut
    Posts
    331

    Default

    heres a picture at the start of a boil from a few days ago showing the windows on the cupola.
    20180212_132405.jpg
    2016 - 36 Taps - File Cabinet Arch + Food Pans
    2017 - 2.5'x10' drop flues - 3/16 Natural Vacuum - 122 Taps
    2018 - 16x20 Sugar Shack - 3/16 Natural Vacuum - 235 Taps

  6. #6
    Join Date
    Mar 2005
    Location
    Albion PA
    Posts
    5,099

    Default

    First I grew up boiling in a old sugarhouse with a cupola. Steam was down at the level of the pans (a 3 x 10 Warren rig) Yea google that one! Someone would come in and not know if any one was in there unless you spoke. Used a flashlight to look through the steam to see the thermometer in the syrup pan. You wore your jacket to try to stay dry. Man was that fun! So 20 years ago when we decided to build our own sugarhouse we went to look at a lot of places first. Yes I like the look of a conventional cupola which screams sugarhouse and maple syrup here! But I was concerned about the steam and the rain. We wanted a place where friends and family and guests could visit and be comfortable. A sauna in the rain forest was not what we desired. Our rig is jus a little bigger than yours. I see you want to increase your boiling rate. My guess is your about there now at 60-70 gph? So here is a picture off our 3 x 10 at about 120 gph. (has steam away) Yep designed and vented hoods control about 95% of the steam in the room. No sauna and no rain inside the sugarhouse. Wasn't cheap, wasn't easy, but the results are very desirable. assuming that's the final thing you desire. BTW we have folks drop in all the time to set a spell and visit too.

    Most of the steam you see on the left side is from the 30 gallons of hot condensate per hour coming off the steam away.



    BTW you have a very nice looking sugarhouse!

    Regards,
    Chris
    Last edited by Sugarmaker; 02-17-2018 at 12:04 PM.
    Casbohm Maple and Honey
    625 roadside taps + Neighbors bring some sap too!
    3x10 King, WRU, AOF and AUF
    12" SIRO Filter Press.
    2015 Ford F250 PSD sap hauler
    One Golden named Maggie, Norwegian Forest Cat named Lucy
    Too many Cub Cadets
    Ford Jubilee and several Allis WD's, and IH tractors
    1932 Ford AAB ton and a half, dump truck

    www.mapleandhoney.com

  7. #7
    Join Date
    Mar 2015
    Location
    Ontario
    Posts
    12

    Default

    Cracking the door or window open doesn't fix this? Our cupola makes too much draft. It'll get cold in the room even with all the heat.

  8. #8
    Join Date
    Mar 2013
    Location
    West Sumner, ME
    Posts
    250

    Default

    We have a steam hood and 2 10" stacks with 648CFM Fantech fans in each. With both running wide open its amazing the cupola stays attached to the roof. Dial them back a little and things vent nicely. We do have to crack a few windows.

    20180225_112415.jpg20180225_145228.jpg
    West Sumner Sugar House
    West Sumner, ME
    500 +/- Taps - 2 x 8 CDL Venturi - 3 Shurflo Solar Systems - MES Dolly 300
    https://www.facebook.com/WestSumnerSugarHouse

  9. #9
    Join Date
    Mar 2008
    Location
    Lake County Ohio
    Posts
    1,628

    Default

    Quote Originally Posted by BSD View Post
    heres a picture at the start of a boil from a few days ago showing the windows on the cupola.
    Attachment 17646
    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.
    John Allin

    14x18 Hemlock Timber Frame Sugar House 2009
    Leader 2x6 w/Patriot Raised Flue Pan 2009
    Leader Steam Hood 2014 - Clear Filter Press 2015
    Leader Revolution Pan and SS Pre-Heater 2016
    CDL Hobby RO & Air Tech L25 Hi Vac Pump 2019
    06' Gator HPX to collect wood & sap
    14' Ski-Doo Tundra for winter work in the woods
    Great Family 3 grown kids+spouses and 7 grand kids who like the woods
    7th Gen Born in Canada - Raised in Chardon Ohio - Maple Capital of the World..<grin>.

  10. #10
    Join Date
    Jan 2016
    Location
    MA
    Posts
    588

    Default

    I agree with johnallin. You need air vented in to replace air escaping through the cupola. The incoming air must be as low to the floor as possible. How warm is it inside the sugar house compared to outside? A cupola is really no different than a chimney. The greater the temperature differential (between inside and outside) the greater the stack effect (like a chimney) will be and the better the venting.

+ Reply to Thread
Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts