Pellet stove vent to exsiting fireplace

[joe1979]

Hi all,

I moved to a new house and brought my pellet stove with me. The new house has a wood burning fireplaces. There are 3 wood burning fireplaces, one in the living room wall, behind the wall is the master bedroom, which also has a wood burning fireplace. The basement also has a wood burning fireplace. All of the fireplaces come to the same chimney, however, each one has its own flue (stainless steel from what I can tell or just regular steel). Each fireplace also has its own cap at top of the the chimney.

I want to install my pellet stove in the living room and vent it through the fireplace. In doing research, I only come across posts that talk about using an existing masonry chimney and to add a liner. However, I don't have a masonry chimney. It is literally all metal behind walls.

The fireplaces have a damper and I measured the diameter which is 8". My question is, can I remove the damper, install a 3" x 8" pipe adapter, seal the sides and attach the 3" pellet stove vent to the pipe adapter. I don't see why it wouldn't work without installing a new liner. The existing wood burning fireplaces are clean and hardly used. I actually intend to just install the pellet stove in the winter then put it away in the summer, then hook it up again the following winter, etc.

Any feedback is greatly appreciated!

Thanks in advance,
Joe

 

[fmsm]

You should be able to do this no problem. I would run a 4 inch flex pipe to the top and “stuff” the area around the pipe with roxul instead of using any adapters. Run the pipe to the top and attach to a cap. As always, check with your local building department.

 

[joe1979]

You should be able to do this no problem. I would run a 4 inch flex pipe to the top and “stuff” the area around the pipe with roxul instead of using any adapters. Run the pipe to the top and attach to a cap. As always, check with your local building department.

Ok, so I couldn't just vent directly into the existing chimney without a liner? I was hoping to avoid buying the liner/pipe. Is it required? I am looking at a 25' x 4" pipe kit on Amazon, which is rated to max temp of 500F. It is aluminum and not steel. I don't think the pellet stove exhaust would come close to 500F. Would this work? I don't want to spend hundreds of $ on super expensive dual wall liner.

 

[johneh]

If the chimney wast designed for a wood fireplace you do not need a liner
The pellet exhaust is a lot cooler than a wood fire. Make your adaptor and enjoy the heat

 

[joe1979]

If the chimney wast designed for a wood fireplace you do not need a liner
The pellet exhaust is a lot cooler than a wood fire. Make your adaptor and enjoy the heat

Thanks, yes the original fireplace was designed for a wood burning fireplace. I've looked in the attic and it is just metal piping going from the fireplace out through the roof and into the chimney.

Here is a picture of what I an envision. I am sure it will work, I was just puzzled that some people still seem to say a liner is required. Will the fact that it goes from 3" to 8" pose a venting issue?

 

[fmsm]

Ok, so I couldn't just vent directly into the existing chimney without a liner? I was hoping to avoid buying the liner/pipe. Is it required? I am looking at a 25' x 4" pipe kit on Amazon, which is rated to max temp of 500F. It is aluminum and not steel. I don't think the pellet stove exhaust would come close to 500F. Would this work? I don't want to spend hundreds of $ on super expensive dual wall liner.

The flex pipe is fine as long as it’s rated for pellet exhaust. I would go this way as opposed to 3”. As always, check the owner’s manual and with your building inspector/fire department.

 

[johneh]

I see no problem venting into an 8in. insulated chimney!
It will draft fine ( inside the house envelope, sealed)
I have been using a 6 in. insulated pipe (16 ft.) for the last 19 years
without a problem