Steam venting options?

[mol1jb]

Hey all,

Have a little dilemma here. I really want to get a steam hood for my new 2x6 evaporator but I am having trouble working out the venting for the hood. It is a new operation in an existing dining hall and kitchen. We will be working in the kitchen. The kitchen has an attic and a gable roof with a brand new metal roof and it would be my last choice to cut into it. Is there a feasible way to get the steam vent out of the end gable wall but still utilizing stack effect? My current thoughts on the matter are going up straight to the attic and then going 45* for about 10ft to exit the end gable wall then back up straight for probably another 10ft.

Thoughts on this proposed method or other better ideas?

Thanks,

[maple flats]

A question first, how is the 2x6 evaporator being fired?

[mol1jb]

A question first, how is the 2x6 evaporator being fired?

Wood, with the chimney piped up near the ceiling, 90* out the back wall and 90* up along the gable end wall.

[maple flats]

The smoke stack is not intended to go up near the ceiling then horizontally out then back upward. If you must go out a wall, slope it towards the exit and do not have the exit less than 3' from the top of the wall unless the ceiling and wall are non combustible. They must be protected or you will set the place on fire. 3' clearance minimum. Protection can take different forms, a layer of sheet metal spaced out 1" on a con combustible spacer will reduce the necessary clearance to 18" a second layer spaced an inch cuts it again and so forth, each layer reducing the needed clearance by half. Masonry on the wall and ceiling will make it safe too. On a wood fired arch you will be burning the fire as hot as it will burn, often adding wood every 5-7 minutes and adding as much air as you can to make it burn hotter.
For the steam stack, the clearance is not a requirement, since non pressurized steam will not exceed 212F, but a "smoke stack" could hit 1200-1500F or more. The steam will exit better if also sloped upward, but the slope angle is not as critical as the wood smoke stack.
This being said, going straight up with both is the best way. Just make the smoke stack design such that you don't heat the adjacent wood, it must be protected, with either spacing as described above or you can use ceramic insulation. Mine has 2" ceramic insulation, then a layer of sheet metal to protect the insulation. Where it goes thru the steel roof get a roof jack. For that i suggest you get a roof jack sized to run 2" larger stack so you can upgrade as you grow without needing to get a larger roof jack. Get, make or have made locally a roof jack designed to a maple evaporator stack the size you will be getting.

[maple flats]

The steam stack roof jack can be much simpler, because the heat is under 212F.

[mol1jb]

The smoke stack is not intended to go up near the ceiling then horizontally out then back upward. If you must go out a wall, slope it towards the exit and do not have the exit less than 3' from the top of the wall unless the ceiling and wall are non combustible. They must be protected or you will set the place on fire. 3' clearance minimum. Protection can take different forms, a layer of sheet metal spaced out 1" on a con combustible spacer will reduce the necessary clearance to 18" a second layer spaced an inch cuts it again and so forth, each layer reducing the needed clearance by half. Masonry on the wall and ceiling will make it safe too. On a wood fired arch you will be burning the fire as hot as it will burn, often adding wood every 5-7 minutes and adding as much air as you can to make it burn hotter.
For the steam stack, the clearance is not a requirement, since non pressurized steam will not exceed 212F, but a "smoke stack" could hit 1200-1500F or more. The steam will exit better if also sloped upward, but the slope angle is not as critical as the wood smoke stack.
This being said, going straight up with both is the best way. Just make the smoke stack design such that you don't heat the adjacent wood, it must be protected, with either spacing as described above or you can use ceramic insulation. Mine has 2" ceramic insulation, then a layer of sheet metal to protect the insulation. Where it goes thru the steel roof get a roof jack. For that i suggest you get a roof jack sized to run 2" larger stack so you can upgrade as you grow without needing to get a larger roof jack. Get, make or have made locally a roof jack designed to a maple evaporator stack the size you will be getting.

I appreciate your concern. I have installed several wood stoves in the past so I am no stranger to proper clearance to combustibles. Believe me I never skimp in that area.

[MISugarDaddy]

As Flats suggested, it would be best to run the pipes on an angle rather than with 90 degree elbows and then flat for a distance. With the steam pipe that may cause you a problem because as the steam moves through the pipe it will be condensing on the sidewalls of the pipe and running back down into the evaporator and every place you have a pipe connection it will probably leak if the pipe runs flat. Also, speaking from experience, elbows in steam pipes are prone to leaking, even if the joints don't leak.
Gary

[mol1jb]

As Flats suggested, it would be best to run the pipes on an angle rather than with 90 degree elbows and then flat for a distance. With the steam pipe that may cause you a problem because as the steam moves through the pipe it will be condensing on the sidewalls of the pipe and running back down into the evaporator and every place you have a pipe connection it will probably leak if the pipe runs flat. Also, speaking from experience, elbows in steam pipes are prone to leaking, even if the joints don't leak.
Gary

Thanks for the reply Gary. I only plan to have the smoke pipe with 90*. The steam pipe I hope to have a max of 45* when I need them. So it sounds like the steam pipe option I have planned will work out fine.

[mol1jb]

As far as venting pipe is galvanized or aluminum acceptable? Either of those options would keep the cost down.

[maple flats]

If talking steam pipe, aluminum or SS are used. Galvanized steam pipe will put some lead back in the pans from drain back that misses a catch tray. By the way, you want a catch system under a steam stack because a lot of the steam condenses out and drains back, if you allow that to land in the pans you then need to evaporate it again. My hoods each have a large rather flat funnel under the steam stacks, then each has a drain channel that empties into the gutter around the inside of each hood. The syrup pan hood drains into the flue pan hood gutter and then a drain connection empties into a bucket at the back end of the pans. That bucket on my 3x8 evaporator fills a 5 gal pail with quite warm water in 2-3 hrs and gets emptied to drain.
If talking smoke pipe, heavy gauge galv. or SS are used.

[mol1jb]

For ducting size on a hood for a 2x6 what is appropriate?

Also who is a good supplier for aluminum venting? I can't seem to find anything rigid for ducting work applications.

[n8hutch]

If your not Brand fussy I would suggest that you look for a Tin Smith in your area. I had a local guy build my aluminum steam pipe out of sheet metal for a third of what you would pay a Maple dealer. He made my roof Jacks and everything. Maybe an Amish shop near you?

[maple flats]

I did both essentially. The 2 steam stacks are SS, 15" diameter and the first 6' of each came included with the hoods. After that 6' I got my local tin smith to make 13" aluminum which is hung from above, in the cupola and it extends down about a foot into the 15" SS, I can now raise the hoods which are bolted together to form a single unit by cranking a manual winch I have mounted on one wall. I did buy a base stack from Leader in SS after the original galvanized one needed replacing, but the rest, in 12" SS was made by my local tin shop at far less than Leader's price.

[MISugarDaddy]

Our 2 X 6 hood was made by Smoky Lake and he built it with a 10" steam pipe. I would NOT go any smaller than that when you are having your hood fabricated.
Gary