AHS S130 : Barometric Damper and Flue Diameter Question

Post by **coaledsweat** » Wed. Mar. 23, 2011 9:18 pm

The M fits the same way.

lsayre · Post by **lsayre** » Wed. Mar. 23, 2011 9:26 pm

Many thanks coaldsweat!

ValterBorges · Post by **ValterBorges** » Thu. Jan. 05, 2012 7:34 pm

Freddy wrote:There is a reason to make a baro setup exactly as Axeman Anderson directs. You see, the AA exhaust is fan driven and therefore under pressure. If you use a 5" baro or even a 6" baro with a "normal" increaser, then exhaust gasses will tend to come out of the barometric damper. By having the 5" pipe go almost, but not quite, half way into a 6" T, then the gasses are pushed past the baro where the natural draft of the chimney will pick up and exhaust gasses out the chimney. When the fan first starts you might get a small puff out the baro, but within a second all gasses go up the chimney. If you do not do as AA directs, then gasses will constantly come into the boiler room.

Here's a pic looking into a AA baro. You can see how the 5" goes into the 6". It's a home made rig....they all are!

Freddy,
Would a 6" S260 go into a 7"?

watkinsdr · Post by **watkinsdr** » Thu. Jan. 05, 2012 9:02 pm

Hey Valter:

I've been having problems with exhaust blowing past my type M with the S260's fan running. Any ideas? I was toying with the idea of using a butterfly damper which would close when exhaust gas tried to escape; but, would open to allow normal baro air flow in the opposite (normal) direction after the fan stops running---kinda like a diode in an electrical circuit.

Post by **coaledsweat** » Thu. Jan. 05, 2012 9:55 pm

ValterBorges wrote:Freddy,
Would a 6" S260 go into a 7"?

My AA 260M is 6" into 7". That's what the chimney thimble was, that's what I used.

ValterBorges · Post by **ValterBorges** » Thu. Jan. 05, 2012 10:09 pm

Watkinsdr,
When I clean out at the end of the season I going to put in the 22ga Black Stove Pipe with the T and probably redo the thimble and try this method.

coaledsweat,
What is the recommended RC for 6" inch going into 7"? (6",7",8")?
The baro is on the 7" correct? with the 6" pipe going 1/4 to 1/2 past the opening correct?

McGiever · Post by **McGiever** » Thu. Jan. 05, 2012 10:14 pm

What is the recommended RC for 6" inch going into 7"? (6",7",8")?

Just so you know...a 7" baro. will fit all three sizes...(6",7",8")

But maybe you want to buy it complete in a Tee already

Is not a Type M baro. recommended,rather than a Type RC?

ValterBorges · Post by **ValterBorges** » Thu. Jan. 05, 2012 10:22 pm

McGiever wrote:
What is the recommended RC for 6" inch going into 7"? (6",7",8")?
Just so you know...a 7" baro. will fit all three sizes...(6",7",8")

But maybe you want to buy it complete in a Tee already

Is not a Type M baro. recommended,rather than a Type RC?

I already have one I would rather reuse it, if that's ok?? Field controls site says both are oil/coal. It does list RC as residential/commercial vs M as just residential.
Is it better to run a bigger baro? Does a 7" work better than a 6"?

Should the T be the 7" pipe that leads to the thimble? I guess it would have to be right so you can insert the 6" into it and go 1/4 way in.

Right now I don't have a clean out T, it's a 90 then a 5 degree rise horizontal to the wall. Once you do the T for the clean out do you still want to keep the 5deg incline.?

Yanche · Post by **Yanche** » Thu. Jan. 05, 2012 10:27 pm

ValterBorges wrote:
Freddy wrote:There is a reason to make a baro setup exactly as Axeman Anderson directs. You see, the AA exhaust is fan driven and therefore under pressure. If you use a 5" baro or even a 6" baro with a "normal" increaser, then exhaust gasses will tend to come out of the barometric damper. By having the 5" pipe go almost, but not quite, half way into a 6" T, then the gasses are pushed past the baro where the natural draft of the chimney will pick up and exhaust gasses out the chimney. When the fan first starts you might get a small puff out the baro, but within a second all gasses go up the chimney. If you do not do as AA directs, then gasses will constantly come into the boiler room.

Here's a pic looking into a AA baro. You can see how the 5" goes into the 6". It's a home made rig....they all are!
Freddy,
Would a 6" S260 go into a 7"?

Here's a photo of my 5" stovepipe into a 6" thimble.

More info in this thread:

5" up to 6" Flu Pipe

McGiever · Post by **McGiever** » Thu. Jan. 05, 2012 10:37 pm

and go 1/4 way in.

I don't know what AHS recommends but in the A-A manual the detail is dimensioned, and not so much like 1/4 way in.

Yanche · Post by **Yanche** » Thu. Jan. 05, 2012 11:16 pm

Don't depend on the dimensions. Understand the physics principles of what you are doing. I intentionally put the inter pipe where I did. In the position shown most of the draft bypasses the damper and pulls on the stovepipe. Measure the draft at the breach with the gauge of your choice. If your draft is not adequately controlled by the baro, cut some of the pipe away. Cut an arc in the inter pipe by gaining access through the baro. This allows more draft air flow through the baro and not through the stovepipe. Ideally you do this on a very windy day and make a judgment on how far you want the baro flapper to open on a windy day. Obviously the factory weight cal settings mean nothing in this use. You must use a gauge to set it.

The advantage of this dual pipe setup is when a "puff back" occurs the inter pipe directs the blast into the chimney stack and not out the baro door. Yes it swings but it doesn't get blown off! If also cleans your chimney, no need for a chimney sweep.

Post by **coaledsweat** » Fri. Jan. 06, 2012 9:22 am

ValterBorges wrote:coaledsweat,
What is the recommended RC for 6" inch going into 7"? (6",7",8")?
The baro is on the 7" correct? with the 6" pipe going 1/4 to 1/2 past the opening correct?

I used a 7" because that is what the TEE is, it is the larger of the two diameters used. 8" is what it calls for but I did not want to change the thimble. If you don't have a big draft and already have a 6" baro, it may work fine.
The M is what Field Controls recommends for coal fired units, the R/C will work fine however. The smaller pipe should be just shy of center of the TEE, about 1/2" to 1" should do it.