Are 90 degree elbows a problem?

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slackercruster

New Member
Oct 21, 2011
28
Am putting in a sauna stove and was looking at a chimney route that uses 2 - 90 degree elbows. One inside and one outside. (the outside being a through the wall chimney elbow.)

Was told 90 degree elbows can mess up the draft. Is this true? I'd be using the stove once a week on average for about 2 hours or so, hopefully with wood pellets.

I can go through the roof, but it still requires 2 elbows to move the pipe to miss the trusses.

Which route (wall or roof) would work best with 2 elbows?



Thanks
 
45's work better if you must have bends. I'm assuming that the chimney will be pretty short. The concern is that the 90's coupled w/ a short chimney will reduce draft and not make the stove operate properly, smoke back at you, etc. What kind of stove is going here? If it's an older pre-epa unit, the concern will be less.

pen
 
So many varialbes... How tall is the chimney is really the key ?

Shawn
 
I'd get the manual for this stove before doing any chimney work and see what their specifications are for chimney height.

pen
 
pen said:
I'd get the manual for this stove before doing any chimney work and see what their specifications are for chimney height.

pen

+1. Find out what the manufacturer recommends before you
build something that won't perform adequately...
 
Most require a minimum of 13' or more of chimney. Many times you can get by with less and for a sauna I would expect you could get by with less as the stove won't be burning that long. Generally you can subtract 2-3' of chimney per 90 degree bend; that is, if your chimney is 13', with 2 90 degree bends you effectively have only 9' of chimney.

Having said that, I've used 90 degree elbows for over 50 years now without problems but I do try to keep it down. At present we have only one elbow as we go out through the wall and then up the side of the house with a SS chimney. Should you want to go this route, allow for a minimum of 1/4" rise per foot of horizontal pipe.
 
Not using 90 elbows is better. However, it is done a lot. I have one stove that uses two of them due to the limitations of the stove location in one room, and there is no reasonable alternative. The stove works great. I did, however, after one year's use, decided to add a three-ft. section to the stovepipe to improve draft. But there are thousands of stove installations which use one or more 90 elbow.

I have two other stoves using a pair of 45's and in each case, they work great, too, but no better than the stove with the 90s.

All my stoves are wood-burners, I have no experience burning pellets or using pellet stoves.

Just reread your original post: using your stove that little, I seriously doubt you'll have any trouble with the two-90 idea if you have adequate chimney height, but that is true for any stovepipe set-up.
 
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