Frustration with Osburn 2400i

[shaggymatt]

Been through all the backpuffing causes, and it isn't any of those typical problems/solutions. I posted a couple weeks ago that I spoke to the guys that make the Vacu-Stack product. Excellent resource! We finally narrowed it down to the double elbow that the installer had to use to put my stove in place before connecting up to the Class A liner. He said each 90 degree bend equates to an additional run of 15 feet. Your cap counts as a bend as well, so I essentially have an extra 45 feet of chimney run on top of the ~15 feet it actually raises.

So I guess my options are:
1. Have a mason look at how much brick can come out of the fireplace to straighten out the run to the liner.
2. Do away with the double 90 bend? Not sure if this is possible, theoretically, it would be like a normal fireplace then, smoke should rise, right? In which case, do I leave the liner in place? I know that they used the soft pour insulation when installing the liner. Osburn doesn't require a liner, but recommends one. Would probably have a fireplace guy look at this option.
3. Could I have someone weld a plate over the existing opening? Then cut something further back? Would of course have to ask Osburn about this. Sure it would kill the warranty.
4. Exhausto fan - about $1100 plus wiring. Recommended by the Vacu-Stack guys.
5. Sell the stove, get something that has a rear exhaust or something further back so I don't need that elbow piece.

 

[bruce56bb]

matt

are you 100% sure that the insulation weight is on top of the insulation?

it's just a 5" or so metal slug that sets on top of the insulation blanket.

it is shown on page 10 of their cheesy manual.

bruce

 

[shaggymatt]

Yes. I cleaned the chimney a couple weeks ago. When I took out the bricks and everything to come at it from the bottom, it was in place, and I put it back when I rebuilt everything.

 

[shaggymatt]

oops double post

 

[BrotherBart]

I don't know where that guy is getting his numbers. The rule of thumb I have always seen and heard is that a 90 turn in a chimney reduces effective height by 5 feet. And have never, ever heard that a cap does it.

Somebody is pushing to sell an expensive Vacu-Whatsits.

 

[shaggymatt]

Well.. the vacu-stack won't solve the problem anyway, so trying to sell the product or not, he didn't have a solution that he could offer me.

Granted a bunch of chimney retailers are all trying to sell my the vacu-stack as the cure all.

 

[Jags]

Yep, bends subtract from the effective height of a pipe, not add. With 2 90's on 15 feet of stack, you have and effective flue height of 5 feet. That ain't enough in most cases.

 

[shaggymatt]

So I was also sitting here thinking... Flows... The installer had that piece made which is literally two 90 degree right angle bends.

Wouldn't a "gentle" 90 degree bend provide a better flow path than a right angle bend? I'm picturing water flowing through a pipe, and a sloping bend would provide less resistance than a hard bend.

Something along the lines of this: http://www.sandhillwholesale.com/ga....html?osCsid=71b9cbec1b9d01c52a44fb085b94f7cc

I was also thinking about a segment of flex pipe. Hoping that I could use something more along the lines of that gentle 90 bend piece linked above, and maybe connect it to a piece of flex pipe then to the liner. Won't really know my complete options till I take off the trim piece to see how much space I have to work with.

Honestly, I think that the guy was more proud of the fabrication of that stainless steel elbow than the function of it.