Smoke Smell In Summer

[ribick]

Hi All,
I’m new to the site so please go easy—especially since I tried to do my research here before asking this question.

I own a Travis Industries Avalon Wood Pellet Fireplace Insert Stove. I’ve had it for several years.

I also have an attic fan. And when I say attic fan, I don’t mean the kind that simply draws air out of the attic in the summer , so that fresh cooler air can come in through the attic vents. I mean I do own one of those—but it’s not what I’m talking about.

When I say attic fan, perhaps I should say whole house fan instead. The type of attic fan I am referring to, hereafter referenced as my whole house fan, necessitates—unlike the prior attic fan I describe, that some of the home’s windows be open before energizing the whole house fan.

When energized , louvers in the ceiling just below the attic open, and a giant fan sucks air out of the house via the attic. This decreases the air pressure in the house relative to outside, and this air pressure differential gets resolved by air coming into the house through the path of least resistance---i.e. the aforementioned open windows. The whole house fan can create a nice breeze on days below 90, and it saves on the electric of running the air conditioning.

But sometimes some of this air pressure differential, despite having the windows open, comes in through the chimney, and can create a smoky smell in my home.

More to point. My chimney has 2 flues. One is dedicated to my natural gas boiler and hot water heater in the basement. The other flue has a pellet stove liner in it, that connects to the pellet stove in the firebox on the first floor.

Recently, I had my pellet stove guy in to clean the liner and stove…the latter I’m diligent about myself. Despite this liner cleaning, this smoky smell can still enter the house when the attic fan is on.

So, after researching this on your great forum, I thought maybe I ought to install a sealing damper. But from what little I can see of these products in pictures on the web, they seem to affix to the clay top of the chimney where my metal chimney cap already resides. Can or should you put both a sealing damper and a chimney cap on the same flue at the same time?

Now correct me if I am wrong, but these sealing dampers have a steel cable that drops down to facilitate the opening and closing of the damper. Would I drop this steel cable right down the chimney liner?

Maybe the idea is to separate the chimney liner from the pellet stove in the summer, when the pellet stove isn’t being used, and close the sealing damper, and opening the damper and reconnecting the chimney liner to the wood pellet stove before starting the pellet stove in the cooler months.

Or maybe I should just separate the chimney liner from the pellet stove in the summer, and shove some foam up the chimney liner to prevent this smoky smell during the summer, removing the foam from the chimney liner, and reconnecting the chimney liner to the wood pellet stove before starting it in the cooler months.

Any thoughts on this would be greatly appreciated.

 

[cmonSTART]

The liner should be very tightly sealed at the top to begin with, which should help. Also, the damper area should at least be stuffed with mineral insulation to help seal that off. I do not think a top sealing damper will work in your situation because of the liner size. Does your stove have an outside air kit installed? This would help further isolate the pellet stove exhaust from the house.

 

[ribick]

Thank you for your kind, prompt, and informative reply.

Yes, my pellet stove does have an outside air kit. Despite owning a home from the 1920's with more air leaks than swiss cheese has holes (unlike sealed homes of today or a motor home that truly necessitate an outside air kit so the oxygen in the home isn't consumed by the fire), my building inspector insisted that the optional outside air kit be installed.

This hose snakes from the back of the pellet stove insert, down a trap door opening in my firebox's floor, which I will presume exists (the house pre-dates my ownership) for the purposes of collecting ash in the basement from a conventional fireplace fire (as opposed to the contained fire created by my pellet stove) where another trap door gives access to this ash collection--

The hose then makes its way to a basement window, with one of its window panes removed, in place of snug hardware which holds the hose end. Outside the home is a galvanized vent that permits air only, not for example animals, to come into the home.

I should explain more. The fireplace damper is permanently open--allowing the chimney liner to go through it. I think what your saying is that shoving mineral insulation into the damper, all around the chimney liner--at least during the warmer months when the pellet stove is not in use and the whole house fan is, may be the best way to go.

Would keeping this insulation in the damper during the winter be a no no? After all, it's only the outside of the chimney liner that gets really, really hot.