Do I really need a liner?

[Gadget]

I am Getting ready to install VC Resolute Acclaim 2490 w/ 6” round outlet.

Chimney has dual flue tiles each having an interior dimension of 6.5x10.

Planning on converting to oval which will get me through my damper without sawing and reduce any clearance issues in the flue tile.

Option 1.) The plan is to buy a round to oval tee & 5’ of oval flex pipe and just run it into one of the flue tiles about 1.5’ and stop there, and stuff some rockwool around it.

Option 2.) Start with Option 1 and continue on from there with double wall rigid oval pipe all the way to the top with a cap.

Is option 2 worth the extra $400 bucks?

Is it really going to make a difference?

Is there a danger of getting too much draft?

I guess it's just hard for me to get past paying more for the liner than the stove.

Additional info: stove floor to chimney top is 16’.

Thanks for your advice.

 

[pinewoodburner]

One question to answer first is what is the condition of your current chimney flue? If there are any cracks or the joints have shifted, your flue will need to be fixed or lined the entire length. You may also want to look at the min. required length of chimney that you need. If it is 15' and you have 16', the liner will draft better where as dumping into the larger existing flue, you may have draft problems.

 

[Todd]

It would be safer and easier to clean with a full liner. And if you feel the draft is too strong you could always add a pipe damper later.

 

[Gadget]

Additional Information:
Flue Condition: Perfect
Chimney location, two sides exposed to outdoors, two sides against home. The top several feet are above the roof line with all sides exposed.

I don't see any suggestion of flue height in the owner's guide. Reading posts on the forum, it sounds like 16' is within the typical range. I don't know if it's of any relevance at all, but the fire place (prior to a stove) had no problems with good draw.

The VC manual does say that chimneys with liners larger than 8x12 nominal may experience rapid cooling of smoke and reduction in draft, especially if located outside. I guess my 6.5x10 interior flue, would be approx 8x12 nominal.

It all sounds borderline. On the one hand I want to do it right and have a stove the runs right, on the other I don't want to throw away money.

 

[savageactor7]

^ then I would say your chimney is out doors and would benefit from a liner. Our centrally located chim was inspected twice by different dealers who said a liner wasn't necessary.

 

[cgeiger]

Gadget - I was in almost exactly the same place you are about 2 months ago, really waffling between a full reline and just a direct connect like you're suggesting. My draft is exceptional, so much so that my VC Resolute would overfire if I wasn't careful when it was windy and my 6" flex could be used as a vacuum to clean out the fireplace (sweep got facefulls of creosote as the draft literally sucked the sweepings up and out). That being said there are some significant downsides to consider with a DC. Namely, you have to take it apart every time you want to clean and you or your sweep will have to clean the entire area of your flue plus the liner portion. If you don't mind taking it apart every time, then this is not as big of a concern. Secondly, you will maintain or increase your draft with a full reline and further reduce the risk of creosote formation due to cooling of the exhaust gasses.

In the end, I did a full reline for about the same price you're suggesting and I did it without converting to flex and back for the same cleaning reasons as above. You can always add a top damper that is more efficient to your FP if you ever want to return it to it's natural, unrefined state You'll need to cut out a portion of your damper plate but it's not that hard.

Ditto on the pipe damper and best of luck!

 

[ikessky]

I feel that the liner is added insurance. Plus, your chimney is exposed to the outside, so I see an added benefit to installing a full liner.

 

[begreen]

With exterior exposure, I'd put in an insulated liner to boot. If this is a straight shot, I'd use regid, insulated, Simpson oval duraliner 4648-OP or equivalent until above the damper plate, then switch to a short length of flex. This is infrastructure that you don't want to have to mess with after it's done. Do it right and it will be safer, stay much cleaner, it will be easier to clean and the stove will perform better. Get off the wallet and do this part right and you won't be back spending bucks to fix it later and cursing your stove in the meantime.

 

[Gadget]

Blueridge, good point on cleaning, I may be under estimating the importance of easy cleaning.

It seems like you all have to clean far more often than I ever have on previous stoves & fireplaces. I have always figured chimney sweeping to be something you do every several years. Perhaps the warmer temperatures here result in less build up, I don't know.

I have a friend who has a VC Encore Cat who ran a short piece of flex to the flue, and has not cleaned his chimney in 6 seasons, heating entirely with wood, and no issues. He of course is telling me I am wasting my money going all the way to he top.

My father heated with a far less sophisticated (dirtier) insert in his home from the mid 70's to the early 90's and never once had his chimney cleaned. Again, I don't know if the temperatures here reduce the build up, or if these two examples are haphazard practices. We don't use pine or fir here, as oak and hickory are plentiful. Needless to say, pulling out a piece of flex to clean every 5 years is far less of a concern than once or twice a season.

BeGreen, the 4648-OP Simpson Duraliner oval is exactly what I had in mind. Already got pricing, which would be the additional $400 I mentioned earlier. I don't know how I could eliminate the flex between the stove and the beginning of the flue tile as you suggested though.

Thanks for the opinions everyone.