Smoke in Basement - what are my possible solutions?

[Bushfire]

The set up:

I have a fireplace xtrodinair elite 33 insert upstairs with a lined flue into an outside brick chimney and a morso 3450 in the basement that is fed into a second flue in the same brick chimney.

The problem: smoke enters my basement when the elite is burning through the morso secondary air supply that, for those unfamiliar with the morso, is always open. If the secondary air could be closed, I think the problem wouldn't exist. I know that the smoke is being pulled down that second flue opening as both flues are at the same height.

The question: Other than extending one of the flues, what are my options for stopping that smoke from entering the basement. I did a quick search online and found dampers that could be placed just above the stove outlet, but they looked as though they were not "airtight". See at: (broken link removed) I'm sure that enough air would still enter the stove and therefore find it's way out through the secondary air supply. Maybe not?

I Know that I could extend the flue, but we're going to be selling the house in the spring and I was looking for a cheaper, quicker fix, but maybe there isn't one. I also want a safe fix. The strange this is that we've had this set-up for two other seasons, and while we did have a little smoke before, it was nothing like we're experiencing now - maybe it's just the weather. I really want to enjoy our last season of burning in this house, and right now this is proving to make things difficult. My other solution may be to always have the morso running, thus preventing the downdraft, but I only fire that up about once or twice a week when I'm working from home.

Any help would be much appreciated.

 

[begreen]

Sounds like you've summed it up pretty well, though I don't think this is being pulled in via the Morso secondary air. If the Elite 33's flue is lined, can a short extension be added to the top?

 

[Gooserider]

First thing I thought of as soon as I read your problem was to extend the flue on the fireplace. The in-pipe dampers are deliberately designed not to be smoke tight, so they won't help significantly. You MIGHT benefit from weather sealing, especially in the upper reaches of the house, to move your pressure plane down and fix the negative draft on the basement stove, but that's iffy.

I know Craig would love to sell you an Extendaflue, but there are probably other lower cost options such as mortaring on an extra foot of clay flue tile, or possibly just sticking an extra 1 foot length of stove pipe up there (This would at least be a good temporary test to see if it solves the problem BTW)

Gooserider

 

[Bushfire]

BeGreen,

I'll double check the secondary air intake, but I'm fairly sure that's where the air is making its way into the basement (down the flue, into the stove and out the intake). I could add length to the lined flue, but my roof is strictly a professional job (something that may be hard to come by at this time of the year and I'm also trying to keep costs down as we'll be selling the house in the spring and I hate to sink more than necessary into the job) and if I remember correctly the flues are very close as they come out of the chimney, making a rain cap very difficult in install if one flue is higher than the other. Does that make sense? Maybe I just need to take that expense and know that I have a system that works well.

Am I right in thinking the in pipe damper (the cheaper solution) will NOT do the trick? (EDIT) Oops, took me to long to post so I missed gooseriders comment on just this.

 

[Todd]

I had this problem a few years back. I extended one flue and added a Condar air supply ventilator in my basement to help the negative pressure. No problem after that.

www.condar.com

 

[Bushfire]

I already have the condar air supply in the area of my basement with the boiler, so looks like my solution is to extend the flue.

Thanks for the help.