Inserts vs Free Standing Stoves and Air Control

[jadm]

Last night, when I was fiddling with the fire, it dawned on me that those of us with inserts have a disadvantage when it comes to burn times due to the fact that we can only adjust the primary air while those of you with free standing stoves can adjust the air on your flues too.

Is that true?

 

[Backwoods Savage]

Not true. Our stove has only one draft adjustment (other than engaging the cat.).

 

[offroadaudio]

True - if an inline damper is installed in the stove pipe - BUT, not always the best thing to do.
A stove with the correct amount of draft, good fuel and proper operation will put out the BTU's that it is rated for - insert or free standing.
An inline damper can be used effectively to reduce draft in a situation where an appliance tends to run away or consume too much fuel because of overdraft.
The flip side is too much reduction and you get a dirty burn and lots more creosote.

 

[Funk Brother]

Perp - briefly put, I believe a flue damper can be very beneficial, and I changed the setup of my insert to allow for it. I own an Avalon Olympic (with blower) and started out - four winters ago - with the usual insert setup using panels to block off the portions of the fireplace opening not filled by the insert. I was disappointed in the heat I was getting from the stove. By the way, my stove is located in a fireplace on an exterior wall in the lower level of a tri-level ranch, using a full 6” flexible liner which runs up about 20 feet. I decided I was losing too much heat up the chimney, and to the firebox bricks hidden behind the shrouding as well. My approach to getting the most heat into the room was to add a flue damper, and also to insulate the old fireplace firebox with kaowool (top and sides), held up by sheet metal tapconned into the masonry. This may not be the ultimate solution, but I think it has increased the heat output a lot.
Stove and damper theory from an expert (I'm not one) can be found at: https://www.hearth.com/econtent/index.php/wiki/why_stoves_overfire_from_too_much_draft/ The author, Mr. Gulland, is not a big fan of flue dampers because they are subject to operator error - specifically leaving them shut when opening the stove door results in spilling smoke into the room. Yeah, I admit, I’ve done that a few times, but it's largely a self-limiting behavior. Overall for me the flue damper was a simple and very helpful addition to my insert setup. I was not concerned with over-firing in the sense of a “runaway” fire, but rather just disappointed that I was going through too much wood too fast and losing too much heat up the flue.

 

[jadm]

Interesting article.

I don't need to change my set up. I get loads of heat that keeps us very toasty even on the really cold days here.

My question was more out of curiosity - getting more info. on how all of these wood burning devices work.