Cold Chimney - draft inducer or extend chimney?

[Tom Knauer]

Hello. We have a brand new Avalon Spokane wood stove in our basement connected to an exterior chimney with brand new liner. We have trouble getting a draft started. I called a notable chimney sweep to the house to get his opinion on the problem, and he concluded the problem was the classic cold chimney, and suggested either installing a draft inducer or extending the chimney a couple of feet (though he said that the chimney was not too short according to normal standards, but that extending the chimney might help). I believe that I can buy and install a draft inducer, or buy and install a chimney plate and a section of chimney pipe, for about the same price and same amount of trouble. So, my question to the forum: any opinion on which solution seems preferable or more likely to solve the problem? If the draft inducer is the best option, does anyone know if this must be turned on for the entire time the fire is burning, or only until a good draft has been induced?

Thanks in advance for your thoughts.

Tom

 

[Slow1]

I was surprised at how much improvement I saw adding only 3' to my chimney.

IF both are about the same cost and effort, consider that cleaning a chimney that is a couple feet taller is far less additional maintenance than any mechanical device with moving parts.

 

[zzr7ky]

What is the chimney & liner set-up like now?

How often do you burn and for how long?

What happens if a nearby window or door is crackked open?

 

[begreen]

Indeed, we need more information. Is this a 6" liner? How tall. Describe how the stove is connected to the liner.

If at all possible, I would recommend trying to find a passive solution that works well. With currently warming temps, draft is going to be poorer, so you may not see the best results right now.

Also, are there competing appliances in the basement like bath fan, dryer, gas hw heater? Are there any upstairs windows open at the time of testing?

 

[Tom Knauer]

Stove pipe through thimble in basement wall to brick exterior chimney. Chimney goes up exterior of single-story chalet-style house. Brand new liner, cap, thimble, stove pipe installed when new stove was installed.

We do not currently use the stove due to the drafting problem. We have tried the open door trick to no avail. The cold chimney is just too hard to overcome!

Once we install a solution we will likely use the stove frequently. We've got a hearthstone in the front of the house that we burn for about 12+ hours a day during the winter, with backup oil furnace. Whenever we get the avalon burning it will not only provide heat for the basement, but will also supplement heat for the rooms above and will hopefully reduce our oil bill.

 

[Tom Knauer]

Yes, 6" liner, and while this is a complete guess, I'd say total chimney length is about 20 feet. Again, the chimney sweep that looked at it said that it absolutely meets standard chimney height requirements.

We have not attempted to start recently in this warm weather.

There are definitely potentially competing appliances, but when we have attempted to start a fire in this one we have made sure that none of them are actively competing.

Would an upstairs window that is open hurt or help? We generally do not have any windows open.

 

[cmonSTART]

Is the liner insulated?

Personally, I would opt for the 3 foot extension, properly done.

 

[begreen]

Agreed. Also, if the stove is connected to the liner with single wall pipe and a 90º elbow, this can be improved by using double-wall connector pipe and softening the angle with a 45º, small offset connector, then another 45º into the thimble.

An open upstairs window or open attic vent, might create negative pressure in the basement. If opening a window or door near the stove improves draft noticeably, that is a sign of low pressure there.

 

[Tom Knauer]

Thanks for the input everyone. I like the idea of the passive rather than active solution, i.e. the extended chimney rather than draft inducer. I also appreciate the idea of the two 45 degree angles rather than the 90, while using double-walled stove pipe. This is a novel approach that I hadn't previously heard. Will definitely look into this addition. I wish the folks that had sold and installed the stove had thought of these things two years ago!

 

[Tom Knauer]

By the way, with the 45 degree stove pipe option, is the double-walled pipe suggested to meet clearance requirements, or does it serve some other purpose? If it is a clearance from combustible surfaces concern, the hearth is made of cinder block (ugly as sin, not my design, bought the house that way), so I don't know if that changes the equation at all. Thanks.

 

[zzr7ky]

Hi -

I added 3 feet of Class 'A' insulated chimney to my existing set up, which is similar to yours. It worked for me. I think that with going to 45 degree elbows would also help.

I have a 'transition plate' bolted to the top plate at the top of my chimney that allows me to attach a 3 foot section of class A. It is also easy to remove and cleen the stackfrom the top.

Mike

 

[Tom Knauer]

Thanks Mike. That was my plan. I'm assuming that the "transition plate" is the same as what I've been calling a "chimney plate", that is, a legitimate way to secure the class A chimney pipe to the top of the brick chimney. I think for a few hundred bucks and a half day of labor I'll be up and running with these suggestions, just in time for summer.

 

[begreen]

By the way, with the 45 degree stove pipe option, is the double-walled pipe suggested to meet clearance requirements, or does it serve some other purpose? If it is a clearance from combustible surfaces concern, the hearth is made of cinder block (ugly as sin, not my design, bought the house that way), so I don't know if that changes the equation at all. Thanks.

Double wall pipe will keep the flue gases hotter. It may help the chimney warm up faster to establish draft.

 

[cmonSTART]

Even before extending the flue, the first thing I would do is make sure the liner is insulated.

 

[Backwoods Savage]

Thanks for the input everyone. I like the idea of the passive rather than active solution, i.e. the extended chimney rather than draft inducer. I also appreciate the idea of the two 45 degree angles rather than the 90, while using double-walled stove pipe. This is a novel approach that I hadn't previously heard. Will definitely look into this addition. I wish the folks that had sold and installed the stove had thought of these things two years ago!

Tom, this is just one of the easy ways to fix some minor problems. Most folks, including installers simply think first of the 90 degree rather than using the 45's. Another thing some forget is the horizontal part needs a minimum of 1/4" rise per foot of horizontal and that can make a huge difference in drafting. We went 1/2" rise per foot of horizontal and are happy with the results.

I also think you may very well have to take extra measures each time you light a fire in that stove. Perhaps just lighting a bunch of paper or using a torch to start heating up that flue before you get the fire going. It may seem a bit tedious but you'll find it really is not that bad of a chore and doesn't take that long either.