Hmmm, using exterior chimney to as chase for Oslo

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mossycup

Member
Dec 4, 2010
73
Northern Illinois
Recently, in another thread I found some great help in deciding to purchase an Oslo for our home. Now that I am on track for the stove, I am looking for the best of two ways to attach the liner the stove.
I would love to run directly up in another location in the room but there really isn't another ideal spot.

In our case, we are working with an exterior wall, very wide, outside masonary chimney. It does punch through the soffit and lower slope of the roof for about 18", but for the most part it is all outside. It is also exposed, full width to the ceiling inside the family room of a single story house. It is lined with 13x13 clay that we will use to chase the 6" SS insulated pipe in.
There is a cantalevered concrete/stone mantle that we are going cut back if needed as we are going to reface the ugly brick with stone, yet to be decided on. We may use the mantle as an attachment aid if we do a different mantle...but this may be dependant on our venting method.

We are removing an old, direct vent insert and planning on cutting back the cantalevered hearth and positioning the stove in front of the fireplace on a floor hearth. Our original plan was to vent to the rear with a short pipe into the old insert opening, to a cleanout T, and connect to the liner. Basically, one 90 degree turn. When we reface the fireplace we would close up the hole and install an appropriate thimble as required.

The other method I've been reading about regarding draft with a chimney of our style is to vertical vent 36-48" to a 90 or combination of 45s and then punch into the chimney to tie into the T higher up.

(Un)Fortunately, we are going to have to replace the top few feet of spalling brick and re-crown, so if we need to provide more SS pipe height than 15' to "tune" draft, it makes sense to work it out before we bring in the mason;)

Is the venting issue moot between these two methods or is one going to work better than the other?
 
I'd probably try rear venting first in this case. Just be sure the connector pipe to the tee is pitch nicely uphill at a minimum of 1/4" / ft. (But if you can increase that to a greater pitch, all the better. No thimble necessary if the fireplace opening cover is metal with a hole for the flue to pass through it.
 
Thankyou BeGreen.

A horizontal connecting pipe entering the old firebox/insert opening as you mentioned was our original plan. A sheet of metal until we refaced the old brick would also keep the area clean appearing and the cats out of mischief.
I have been studying the NFPA 211 and the F 500 manual but I cannot narrow down the procedure that a single wall connector will require to pass through a piece of metal into the masonary cavity to the T...also, I am concerned with any heat issues in the cavity behind the cover that may occur, especially if we close up the damper opening around the flue. This would also hold true when we eventually close over the opening with our chosen facing material. What is the correct method to accomplish what we are after
There is a clean out at the back of the chimney that will still allow us access to the T cap, so we will still have access for maintenance.
 
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