Woodstove - Side Vent vs. Top Vent?

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New Member
Nov 29, 2007
Cape Elizabeth, ME
I may be overthinking this but figured I'd ask for opinions before I choose a knockout.

I have a Jotul #3 CB woodstove that I need to convert from a rear vent to either a side vent or top vent because of it's new installation location (in a corner attempting to minimize wall clearances as much as safely possibly). Is there any difference in efficiency or performance between side and top venting?

Beacuse of how I will connect the doublewall stovepipe to the ceilingplate, if I side vent, I can go directly out the side into a tee and then straight up to the chimney, through the attic and to the heavens.

If I top vent, I'll go up 4' to a 90 el, into the tee and then straight up said chinmey.

I'd prefer to side vent for a number of reasons.
- In this installation it will look aesthetically better.
- It avoids needing the extra double-wall el saving money and one less obstacle for the smoke to navigate.
- Leaves the top of the stove open for a kettle and/or eco-fan.

If there's a significant benefit to top venting, I'm happy to do it, otherwise, I'll pop out the side knockout and go that way.

BTW, anyone have any tips on how to best break out those knockouts? I'm paranoid the stove is just going to shatter into bits.

Thanks for any advice and help.



Staff member
Your post would indicate that the knockout is already out of the rear flue hole. If so ya got a problem. That being that you are going to need a way to cap and seal that rear hole and that is usually done with the cap, gasket and bracket from the top plate of the stove. With the top plate intact you have no cover, bracket and bolts to use for the rear exit hole.

As to knocking out the knockout on the side you just take a deep breath and smack it right in the middle with a hammer. That will produce four nice little cast iron wedge pieces and your stove will be fine. It will then have two open flue exits in it but it ain't gonna shatter.

Personally I would top vent the stove. I believe that it burns better that way than any other. Why can't it be angled in that corner and top vented straight up? Would look good.


New Member
Mar 2, 2007
I went out the back on my F3. It was totally unnerving smashing your new wood stove with a hammer, however I found a regular carpenters hammer did the trick. At first I tried a mini sledge but found the point of impact was too broad and I was flexing the whole back of the stove. As far as the stove pipe...well thats a matter of preference. Im sure either way would work fine. Looking at your hearth design I could see the stove sitting kitty corner with the pipe coming off the top.. Good luck..



New Member
Nov 29, 2007
Cape Elizabeth, ME
Thanks for your posts Bart & Larry.

I have a flue cover with gasket and traverse bar to cover the existing rear hole so that's not an issue. Plus rear heat shields with the knockout hole intact.

I originally wanted to angle the stove in the corner like you suggested but our code enforcement guy had a isses with how the corner of the stove would project across the opening to the living room to the left. Also, by putting it the way it's aligned allows it to be viewed from the seating area in the adjoining room. This is a funky little house that's been remuddled several times in it's history so we're forced to make some compromises with things.

So, do you think there's a significant benefit to top venting?

Also, in knocking out, is it better to hit from the outside in or inside out?



Jan 9, 2006
I just swapped my Jotul 3TD from top vent to rear vent. (new alcove installation)

I observe better burning performance from top vent when trying to bank down the stove. At full tilt it does not apear to make a difference.

I've also noticed that at cold start the rear vent does not work as well as top vent.

I'm guessing its the basics of how smoke likes to travel. Up, not sideways...
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