Should I add more chimney?

[Pat Matterson]

Hello, this may be a little long lol.

We are doing much better with dryer wood this year, and if we really keep it rolling along we can get good heat to spread over almost the entire house. We use a thermostatically controlled electric heater in the one far room (right above stove) we don't get much heat in. The only "problem" we have is we can't seem to get it over 500 if that. We have gotten it to 600 once, ever. The manual for our stove says to keep it in between 4-600. I was thinking if we could get it to push into the higher end of that scale we would get more heat out of our setup.

I am thinking that we may not be generating enough draft. Unless I am mistaken a longer chimney would be a bit harder to get a cold start going but would draw harder once going. Last year we had pretty damp wood and were new at this so we had some beginner issues getting the draft going. These days we can get it going with zero effort, almost immediately. I know I don't need it crazy hot to get secondary burns. We get them going as low as 400, but I was wondering if we couldn't get a bit more out of it while staying in the recommended range.

The advice I was given on the chimney last year was that it is a bit short. I have an extra 4ft piece I could put up to add length or cut to add a bit less. You guys recommended adding it, but I felt like it was doing ok so I waited. The guy from company that came to clean and inspect said that 4ft more would be more than he would recommend and said to cut it at 2ft. Does 2ft make that big of a difference?

I know I am losing a lot with it being by an uninsulated, free standing, slab wall. Believe it or not though, after it saturates, it does spread to the rest of the house slowly. It takes forever, but once it's warm you can maintain it. Anyway here is the stove pipe setup.

(broken image removed)

The stove pipe is double insulated and the I.d. of both the stove pipe and the chimney is right about 6".
Here is a pic of the chimney.

(broken image removed)

The chimney height is about a foot taller than the required 3 ft past where it clears the roof. However it is just a few inches short of the recommended 2ft up from the roof; if you measure 10ft over from the highest part of the chimney.

As far as total chimney height the full length pieces are 4ft x2. There are 2 half pieces, so 2ft x2. And then the bottom clean out, and 2, 45° pieces are like 1ft x2. So without measuring I would say 14ft and a few Inches tall. I live on a pretty steep hillside of a small valley if that is a factor.

Anyway I guess before I climb up on my roof and add either the 2 or 4ft piece I wanted to see which you guys think is better because I do not want to have to change it again. Am I mistaken in thinking it would draw harder with a bit more length?

B.t.w. I am happy with the location, it really does a pretty good job there already and when I need to help get the draft going I can crack that door. The basement is an area we do spend some time in, as our bedroom is, and someday the living room will, be down there.

My last 3 posts on this thread will tell you a lot about how it has burned for us temp wise in the past.
https://www.hearth.com/talk/threads...stall-it-like-this.117482/page-2#post-1827122

 

[rijim]

14' is short without those 90s and 45s, they make it worse; if it were me I would throw the 4' in and see how it works. Don't stuff the fire box full for a while while you gain experience; if draft is too strong and temps start to climb past 700 you can always open door and toss a less seasoned log in the mix to calm it down.

 

[Pat Matterson]

14' is short without those 90s and 45s, they make it worse; if it were me I would throw the 4' in and see how it works. Don't stuff the fire box full for a while while you gain experience; if draft is too strong and temps start to climb past 700 you can always open door and toss a less seasoned log in the mix to calm it down.

Thanks I think we will try that and see how it goes, I can always shorten it a bit if I find it too hard to control.

We actually stayed on top of it the night we posted this thread and kept it rolling along at 5-525 for a while and it was nice and toasty. We may try the auber stovetop alarm to help us stay on it. For now the living room is upstairs and that's where we usually are when we let it burn down too low.

According to the Moisture meter our wood isn't actually all that dry really I guess either. I read in the middle of a fresh split and got 24 of off the big rack inside by the stove that holds a few days worth. (it is outside of the safe burn distances from the stoves manual) I grabbed a piece from the stacks outside (all gotten at the same time last year) and it read 29.

 

[begreen]

Is that an Isle Royale? The reason I ask is that stove breathes pretty easily. If so it may be fine. Adding 4 ft won't harm anything but may not be necessary. If the stove works well and easily comes up to temp then I would leave it alone as long as the chimney top is 2 ft above a straight horizontal line to the roof. It's hard to tell from the angle of the photo.

 

[FTG-05]

What does your stove manual say about the minimum chimney height? My 30-NC recommends/requires a minimum of 15' above the stove height. Having 4 45's plus one 90, I would say you probably could use another 4' of chimney height.

Good luck.

 

[Pat Matterson]

Is that an Isle Royale? The reason I ask is that stove breathes pretty easily. If so it may be fine. Adding 4 ft won't harm anything but may not be necessary. If the stove works well and easily comes up to temp then I would leave it alone as long as the chimney top is 2 ft above a straight horizontal line to the roof. It's hard to tell from the angle of the photo.

It is a Jotul stove, it says Firelight CB on the back and I thought I had found it to be the Jotul Firelight f600CB model but after showing some people the Picture of the one I thought it was someone pointed out that it was a plainer version without some of the designs in the casting specifically at the front top corners. I was told on here when I asked that "The stove does look like the f600 in several ways: loading door on the right side, latching mechanism for the front doors, air control lever. Where it differs is in the front doors. This one has a lattice structure where the newer ones have arches instead. Perhaps this is an early model and the door design was changed." Anyway we have been going by the F600cb manual on the Jotul website.

10 feet over from the top of the chimney is just a few inches shy of being 2 feet up from the roof so it is just a bit short of the recommended there.

What does your stove manual say about the minimum chimney height? No my 30-NC it recommends/requires a minimum of 15' above the stove height. Having 4 45's plus one 90, I would say you probably could use another 4' of chimney height.

Good luck.

Forgot to check what the manual says. "Chimneys shorter than 14ft may not provide adequate draft. this could result in smoke spilling in the room when loading or the door is open. in addition it can cause back puffing which is a buildup of gasses inside the fire box."
It also says "other times" chimney height can cause excessive draft resulting in high stove temps and short burn times.

So we are a few inches over the recommended total chimney minimum height and do not suffer from smoke spilling or back puffing. We also don't suffer any of the issues of too much draft, I may be convincing myself to follow begreens advice and leave it alone lol. Especially after finding out my 1yr old splits aren't as dry as I thought they would be.

The house we took it off of before it got put on mine was much taller and I actually have 4 -4ft sections left. Was going to sell 3 of them of craigslist and keep one in case I ever decided to add a piece.

 

[Pat Matterson]

Changed the ad on C.l. and got a call from a guy that was gonna try and pick up the extra parts this weekend. He is all disappointed I may be keeping a piece but I think it's borderline on needing a bit more length or not.

The inspector that came said this stuff is worth like 100 a foot new. If that is the case the 300 I am asking for 3 pieces, a nice wall mount bracket ($?), stove pipe 90 ($50 new) and stove pipe 2ft section, ($?) Wouldn't be enough to get one piece if I wanted it later. He probably won't buy it now but I am not that worried about it.

We are going to call the chimney cleaner out and have our setup cleaned. I will ask his opinion again, but if we hit a dryer patch of wood I bet it would be right where we want it. I am going to see if I cant find some actual seasoned wood to buy where they can tell me the moisture content to expect. I will post up whatever our results are from either dryer wood or adding a bit for other searchers.
Thanks!

 

[Arlo.]

I have the "F600 CAT" or "Model 12" as it is known. I have a chimney about the same height as yours. Mine measures at 13 feet from the stove. I believe it is recommended for 15 feet. But regardless, mine cooks no problem and I have two 45's in there to avoid the ridge beam. Although mine is top exit into attic. The rear exit and exterior run could require a little more height to get a good pull. Those exterior runs do take some time to heat up as well.

 

[rijim]

Just throw the 4' up there and try it and end the question; with the number of bends you really will be fine.