Horizontal run and draft on rear vent Jotul stove

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Kitchen

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Jan 20, 2013
41
Shawangunk Mountains, NYS
I am looking to replace my Hearthstone Heritage stove with a more modern one. The Heritage has always suffered from door latch problems and is no longer airtight - can't control burns. I have settled on either the Jotul F3 CB or the Oslo 500. My house is overly insulated and tight with about 1500 Sq Ft to be heated - two story. We typically keep the bedrooms at 60 and the downstairs about 67.

The Heritage has a rear vent into 24 inches single wall into a 30 foot Class A pipe running up an outside chase. There is no vertical rise in the 24 inch horizontal stove pipe and the stove drafts very nice. My question is this:

1. Would the F3 CB heat this size house? With the Heritage, if I get the first floor temp to 67 at night, put in a couple of splits so there is just a few coals in the morning, the first floor temperature only drops about 5 degrees overnight when it is about 25 degrees outside. Also, the advantage of the F3 CB with the short leg kit, it would be a direct replacement for the Heritage meaning I could probably have a about 1/2 inch vertical rise in the horizontal run.

2. If I decide to go with the Oslo 500 with the short leg kit, then my stove would be about 2 inches higher than the wall thimble, meaning I would have a 2 inch negative vertical rise. To compensate for this, I would probably get a heat shield and reduce my horizontal run to under 18 inches, use an outside air kit, use double wall stove pipe, but the smoke is still going to travel down 2 inches before connecting into the wall. Since I have a 30 foot vertical pipe and get good draft now with the Heritage, do you think I could still maintain a good draft with the Oslo 500 based on my less than ideal installation schema?


My only other option would be to move the wall exit up a foot, but really would like to try and use the existing connection.
 
1) Depends on where you live, but I'd give it a qualified yes, but with a big caveat. With a 1.1 cu ft firebox you will be feeding it every few hours unless you live in a very mild climate.
2) Doesn't sound like the best fit. What is the exact height at the top of the flue thimble?

Approx. where do you live?
 
Yes...center of flue thimble? You may have other choices in stoves that will allow less clearance, that will match up with your exit thimble...
 
Can you adjust the class a pipe so you can get the 1/4" per horizontal foot? Routing the fumes down over any span seems like asking for trouble imo....May even be a code issue.

The castine (with rear heat shield) reduces rear clearance to 7" i believe.... Would that be a better fit?
 
1) Depends on where you live, but I'd give it a qualified yes, but with a big caveat. With a 1.1 cu ft firebox you will be feeding it every few hours unless you live in a very mild climate.
2) Doesn't sound like the best fit. What is the exact height at the top of the flue thimble?

Approx. where do you live?

I live in Zone 2 - Hudson River Valley of NYS. Night temperatures are averaging between 20 and 30 degrees and again, we'd rather have the house temp between 60 and 67 degrees.
The center of the 6" inch single wall flue pipe where it connects to the double wall pipe coming from the thimble is 20.5 inches. The center of the rear flue for the F3 CB with the short leg kit would be 20.25 inches, giving me the 1/4 inch rise for the 1 ft horizontal run I could reduce my clearance to with the F3 CB.

Thanks for your response.
 
Can you adjust the class a pipe so you can get the 1/4" per horizontal foot? Routing the fumes down over any span seems like asking for trouble imo....May even be a code issue.

The castine (with rear heat shield) reduces rear clearance to 7" i believe.... Would that be a better fit?

Actually the Castine rear flue is 1/4" higher than the 500, which has a rear clearance of 6", so I am going in the wrong direction with the 400.
 
bummer...... the hearthstone and the castine were on my short list because of their shape, size, and clearances.'
 
That's a low thimble. Hopefully some folks can chime in with some options. All Woodstocks are out...center of rear vent flue 22.75 inches.

Hudson Valley of NY is more like Zone 6 or maybe 5 by any zoning I've seen...Ottawa, Canada for instance is Zone 4. Zone 2 would have to be on average 20 degrees F colder than Ottawa.
 
1) Depends on where you live, but I'd give it a qualified yes, but with a big caveat. With a 1.1 cu ft firebox you will be feeding it every few hours unless you live in a very mild climate.
2) Doesn't sound like the best fit. What is the exact height at the top of the flue thimble?

Approx. where do you live?

One other clarification about my heating needs and the existing Heritage. Because it is no longer airtight, I can only put a couple of pieces of wood in it and only then the temp only gets to about 400 degrees at the most - and this is adequate to heat our house. Even with the that, the house retains the heat so well, I can let the stove continue to radiate heat for about 4 hours before the house temp starts dropping noticeably. Comparing the Jotul F3 CB that I could get a fully fired stove with better temps in the 500 - 600 degree range, maybe that will do the trick. I've read that a smaller stove with a bigger fire is better than a bigger stove with a smaller fire.
 
That's a low thimble. Hopefully some folks can chime in with some options. All Woodstocks are out...center of rear vent flue 22.75 inches.

Hudson Valley of NY is more like Zone 6 or maybe 5 by any zoning I've seen...Ottawa, Canada for instance is Zone 4. Zone 2 would have to be on average 20 degrees F colder than Ottawa.

I am looking at the back of the latest Jotul Stove catalog and it puts NYS in Zone 2 out of their four Zone possibilities. Zone 2, in their mind, is the Northeast from Central Jersey including Ct, Mass and most of NYS. According to this, the F3 CB is rated for 1200 sq ft and the 500 is 2000 sq ft. My entire house with the upstairs bedroom that is closed off in the winter, the family room which is heated by another source and a closed off downstairs bedroom is only 2000 sq. ft.
 
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The F3CB can definitely get up to 650F, but expect some regular temp swings with this stove as compared to the Heritage. It's small firebox is the main issue. What would it take to get the Heritage sealed properly again? Where is the problem?

In small stoves take a look at the Vermont Castings Intrepid II. It's catalytic so you will be able to get a bit longer burn time out of the stove. It will burn at lower levels without getting smokey. The centerline of the flue is at 20.5".
 
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