do I need a liner or not?

[harleyberger]

I've been to 3 different fireplace stores. 2 have told me I need a liner, 1 told me I don't need a liner. Here's my situation...

I'll be installing a free standing wood stove in a finished basement (~800 sq. ft.). I'm looking at either a Jotul F 3 CB or a Quadra Fire 2100.

I have an 8" pipe going into the chimney which is 10" x 10" inside diameter clay all the way to the top. It's probably about 25' from the pipe in the wall to the top of the chimney.

I'm concerned that both of the stoves I'm looking at have a 6" flue. I'm assuming that (1) there is an adapter that goes from 6" to 8", and (2) that I'm not going to have problems going from a 6" flue on the stove to a 10" flue in the chimney.

Given these dimensions, can I install one of the stoves listed above without lining the chimney?

 

[Edward Harrigan]

There is simple math to detremine if you need to line the flue.
If the chimney is in the house the flue can be no larger 3 time the area in square inches than the appliance flue collar
10X10= 100 square inchs 8 in is about 50 X 3= 150 square inches so it is ok
if the chimney is outside the house it can not be more than 2 time the area in square inch than the applaiance flue collar
100 sqrare inchs 8 in is 50 X 2= 100 so this is marginal you might want to line this

How ever if you install a stove with a 6 in breech you will need to line it. the stove will work much better.

 

[BrotherBart]

I installed an F3CB in my basement into a clay 7 X 11 tile flue of around 30 feet and it didn't draft or heat worth a damn. I installed a liner and it burns great.

 

[fossil]

Your 6" flue collar has a cross-sectional area of a hair over 28 square inches. Your 8" pipe is a hair over 50. Your 10" x 10" flue is 100. Your flue has 3 1/2 times the area of your stove collar. If you connect it this way, the mass flow rate of the flue gases exiting the stove is going to slow way down. The stove probably won't draw well, and the gases will have ample opportunity to cool on the way to finding daylight, exacerbating condensation of creosote. I don't think you'll be happy with the results. A complete 6" liner from stove to daylight would be the best installation. Rick

 

[RedRanger]

You need to look at Local and National codes. In this country only a partial liner is required for a stove, but a full liner is required for an insert. And in my neck of the woods, the sweeps won`t clean an insert unless it meets code. IMHO even for a stove I think you will get better draft and control with a full liner. And be safer to boot.

 

[stoveguy2esw]

no need to embellish, the guys above are correct , per NFPA211 , chapter 12.4.4 states clearly that interior chimneys cannot exceed 3X the cross section of the appliance collar , and exterior flues cannot exceed 2X the cross section of the appliance collar.

bottom line , you need a liner.

 

[harleyberger]

Okay, so I will be installing a liner.

Since I have a 10" x 10" ID clay flue, it should be pretty easy to get a 6" liner down there, right?

 

[BrotherBart]

Tie a rope to a one gallon paint can and lower it down. If it goes down ok then a liner should fit just fine. Just be careful to not get it stuck in the chimney.

 

[harleyberger]

So if I have the 8" pipe already going into the wall, can I just run 6" pipe from the stove, through the 8" opening, and into the 6" tee on the liner? Is there an adapter that I could slide over the 6" stove pipe that would connect up to the 8" pipe already in the wall?

This shows the 8" pipe already in the wall...