Steam Ventilator

[Urban Sugarmaker]

I am going with a "hatch" that is hinged on one side for a steam ventilator. Same idea as a hatch system with two panels along the ridge line and open opposite each other. Mine will only be on one side because my arch is in one side of the building. See the UVM sugar house design article available online for a description of this type of design. Also see on this forum http://mapletrader.com/maplegallery/boiling/p48-cupola-ventilator.html. I decided this was most economical, easier to build, and much lower profile than a traditional cupola. I'd prefer the traditional cupola design, but for my situation this is better. Anyway, my evaporator is 2x4 and I am planning approximately 44"x27" for the dimensions of the hatch opening. It's slightly more surface area than 24"x48". I'm doing it this way because of the structure of the hatch and the roof. I want the hatch frame to be fastened to my rafters which are about 24" on center (old building built in 1920). The question is, will it matter that the opening in the roof is not perfectly aligned over the evaporator? Steam obviously rises, but with my design will enough steam escape to avoid indoor rain? I'm talking 4-6 inches that this open is offset from the pan.

[christopherh]

No it won't matter, the steam will find its way out. I've had this type for several years but recently built a traditional cupola. Here's the reasons. I use a blower with my evaporator and have found fly ash falling back down and into my flu pans. That's is the biggest reason I built a cupola. Weather wasn't bad. Even on rainy nights I would offset the doors to keep most of the rain out. Hope this helps.

[Urban Sugarmaker]

That's very helpful. Maybe I should modify the design so the hinges are on the ridge side of roof. This would give better rain protection and might help keep ash out. I didn't even think about the ash. The door wouldn't open as far this way, but in a traditional cupola the steam has to find its way out the side doors anyway. Thank you.

[christopherh]

That's a great idea! Good luck