using air control to regulat heat output?

[Black Jaque Janaviac]

I have a V.C. Montpelier insert and I'm wondering if I could get more BTU's out of it by running with the air control open. Up until now, I only open the air control when the stove/fire is warming up and/or when I have a less-than-dry log in (my second year burning with this unit and a damp log sneaks by once in a while).

So, can a guy squeeze out more BTUs by opening the air intake a little more? Or is that strictly for starting the fire?

 

[Dakotas Dad]

In GENERAL.. more air means hotter fire, less air means longer fire.

 

[Black Jaque Janaviac]

Thanks.

I know that more air can also mean more draft - so I wasn't sure.

 

[begreen]

Yes you can, but unless the wood is crap, don't run it all the way open. Try just opening it a bit more. Also, you'll want to watch the stove parts and temp when doing this. Push the stove too hard and it may be in overfire territory (>855°F). If this need is frequent, then the stove is too small for the heating need. The choice is more btus from a larger or multiple stoves or better yet, address the heat losses in the house.

 

[oldspark]

Yes you can, but unless the wood is crap, don't run it all the way open. Try just opening it a bit more. Also, you'll want to watch the stove parts and temp when doing this. Push the stove too hard and it may be in overfire territory (>855°F). If this need is frequent, then the stove is too small for the heating need. The choice is more btus from a larger or multiple stoves or better yet, address the heat losses in the house.

As far as how much to open the primary air when do you think you turn the EPA stove into some what of a smoke dragon or are you always going to get some secondary burning no matter where the primary air is set. I have read posts where some think if you burn the stove wrong you do not get the good out of the secondaries, seems reasonable to me.

 

[begreen]

Good point, too much air can upset the balance of the burn and send a lot of heat up the flue instead of containing the intensity in the firebox. That can result in too high flue temps and possibly lower stove top temps. Secondary burning could still be happening, but in the wrong place, that being the flue.

 

[Battenkiller]

As far as how much to open the primary air when do you think you turn the EPA stove into some what of a smoke dragon or are you always going to get some secondary burning no matter where the primary air is set. I have read posts where some think if you burn the stove wrong you do not get the good out of the secondaries, seems reasonable to me.

What makes a stove a smoke dragon is the ability to shut down the air too much without having the ability to burn off the smoke produced by doing so. The secondaries don't need to be firing away if the stove has enough primary air and good internal velocity (created by a strong draft). Just because the secondaries aren't going doesn't mean the stove is burning dirty, but it will probably be burning a little less efficiently since more air is going through the box and, ultimately, up the flue. Sometimes the highest efficiency must be sacrificed in order to stay warm, but as long as the stove burns clean, doesn't matter where the smoke gets burned as long as it does get burned.

 

[oldspark]

As far as how much to open the primary air when do you think you turn the EPA stove into some what of a smoke dragon or are you always going to get some secondary burning no matter where the primary air is set. I have read posts where some think if you burn the stove wrong you do not get the good out of the secondaries, seems reasonable to me.

What makes a stove a smoke dragon is the ability to shut down the air too much without having the ability to burn off the smoke produced by doing so. The secondaries don't need to be firing away if the stove has enough primary air and good internal velocity (created by a strong draft). Just because the secondaries aren't going doesn't mean the stove is burning dirty, but it will probably be burning a little less efficiently since more air is going through the box and, ultimately, up the flue. Sometimes the highest efficiency must be sacrificed in order to stay warm, but as long as the stove burns clean, doesn't matter where the smoke gets burned as long as it does get burned.

I dont even like the "smoke dragon" thing just use it as everyone seems to understand what you are talking about. I burnt my old stove by flue temps and never had any creosote to speak of, hardly a smoke dragon. I think the differences between the old stoves and the new ones if run correctly are closer than some might think.

 

[begreen]

This is straying very far from the OP's question and a rehash of several old threads. True that an old stove run correctly can burn reasonably well, but no where near a modern stove's efficiency when it is burned correctly and properly maintained. We are talking a magnitude of difference here, 2-4gms/hr vs 30-40 gms/hr. There are some transitional stoves that burn in the middle ground like some of the VC stoves, Haughs and the Kent that Tom mentioned earlier. But the average old stove is not nearly as clean. I saw this sadly with the Jotul 602 this week. It's a great little heater, but there was a lot more smoke than I wanted to see until the stove reached the coaling stage.


Tom has some good articles in his library and a fun one called Smokeless in Seattle. It's an interesting read:
http://www.chimneysweeponline.com/hoepareg.htm
http://www.chimneysweeponline.com/hoarticl.htm

This article is also informative as are the referred to OR test results.
http://www.woodheat.org/technology/EPAstovereport.htm
http://www.epa.gov/ttnchie1/ap42/ch01/bgdocs/b01s10.pdf

 

[HotCoals]

I ran a non cat BK Classic for years.
Two weeks now on the same stove with cat and thermostat..no comparison.
In this shoulder season I'm close to burning just half the wood with a warmer house.
Temps stay way more steady.
Of course everybody knows it takes less btu's to maintain then to climb.