Draft setting for most efficient heat

I let my fire die out, cleaned out the stove and went out and got some pine to start a new fire. Now I can ask a question, what is your flue temperature when you build a fire such as this? My stove will get in the danger zone quickly if I try to build a very hot fire too fast. Just wondering.

 

I wish I could tell you, but I have no means to measure.

 

I've got a probe type Condar on mine,but you can tell by the noise it starts making that it needs to be shut down. This is my first season with this stove and it's been a learning experience.

 

I don't expect much efficiency from a noncat. I run mine hot for highest safe output but I am fairly certain that maximum efficiency will occur at the lowest slowest draft setting which supports complete combustion so no smoke. This means that the exhaust temps will be low, exhaust flow rate low, so less heat escaping up the stack and stove temps pretty high.

 

And just to make your brain cells really spin, get a load of this 1998 artical on EPA stoves.
https://www3.epa.gov/ttnchie1/ap42/ch01/related/woodstove.pdf
Pretty wordy wif some pretty big words and lots of numbers into it too.
As for me? I throw the wood in the stove when the hooch is cold, hooch gets warm. Wife, doggy and me happy.
Heating and cooking with farwood, so easy a caveman can do it.

 

I really dont know how you can run a stove efficiently with out keeping track of flue temps, too low and you form creosote and too high you are wasting wood.

 

Secondary combustion does take place in a non EPA stove when burnt correctly, a hot fire is an efficient fire.

 

How low you talking?

 

I will add in order to heat my house I will run the flue temps higher as long as they are in my comfort zone.
My Summit made my butt pucker as in order to get any heat out of it the flue temps would get in the 800 degree (surface temp) range.

 

I have to cut the draft back on my stove, after the fire is build, to keep the chimney from over heating. I try to maintain 4-500F single wall surface temp until the stove top is up to temp, then shut the stove down. My chimney would overheat in a hurry if the draft were left wide open on a reload.

 

With the bypass closed or open? Cat stoves are a whole other ball of wax.

 

I went back and read your Summit experience a while back (before I started using my stove) and still wonder,I'm sure as you do,what was causing your stove to act like it did. PE told you it sounded like you knew what you were doing,but sorry about your luck. My stove, which I think is the same design as the Summit, has flue temps that really doesn't correlate with the fire I have going. Everything will settle down eventually and it will put out good heat.

 

With the bypass open, on a reload.

You're right, cat stoves are a different ballgame. Soapstone on top of that. Crossed my mind after posting.

 

All I know is that with my Oslo 500 and my some what primitive set up and living here in the flat lands of N.E. Iowa, I sometimes have no control over how much heat is going up the chimney. When the winds are blowing 30 mph outside I could completely shut down the primary air but the air intake at the rear bottom of the stove which is the size of a baseball would still suck a dirty sock across the basement floor. As for stack temps, I usually see 350 to 400° on single wall surface temp. The stove, depending on how I load it and the wood type in the load usually likes to run around 600° stt. I am sure that I could install a key damper in my stove pipe and drastically lessen the amount of draft and heat going up the pipe but I really dont want to do that as I got a feeling it could cause a cold flue and more creosote build up. I am not going to over analyze it cuz I learned a long time ago that doing so just gives me a raging head ache and raises my blood pressure to even higher levels when I cant figure it out any ways. As far as efficiency goes, and this may be comparing apples to oranges but was explained to me years ago by a major plumbing and heating contractor in my area, the higher efficient stoves being installed are going to run hotter, more often and keep a more constant temp in the house than say an old Lennox oil burner that is only kicking on once an hour but has to totally heat itself and the entire house back up. Basically what he was saying is that the more the furnace cycles and for a shorter duration the more efficient it was because it was using less fuel over a shorter period of time to maintain a comfortable temp.
Fact or fiction? I dunno. All I know is what goes on in my back yard. Your mileage may vary.

 

I won't let the surface temps go under 200 but remember the first condition, complete combustion. In order to get that you need to be getting secondary combustion which means pretty hot exhaust. Coolest flue temps possible with no visible smoke has got to be the peak efficiency for about any stove really.

I complicate things by forced air cooling of the stove and flue of my noncat to try and steal more heat.

 

This is a great discussion! my draft was measured at 60 pascal in July.. so plenty of draft! Tom of Woodstock told me to put a key damper in..
Anyhow.. I think a lot of this depends on type of stove.. my stove is a hybrid with CAT.. so basically I want my flue Temps to be as low as possible once cat is engaged.. I often see flue Temps dropping while STT is increasing as secondary and cat temp are increasing.. getting more heat from stove.. as all woodstoves are basically space heaters as long as STT for me is below 700 I would like to see flue Temps below 500 no creosote because cat burns it so more efficient!

 

I just ordered a Condar FlueGard. Now I need to work out the story for the missus as to why it is a necessary purchase.

 

It will be interesting to see what temps you are seeing.

 

I have cat stove too with efficiency equal to the best woodstock. The cat does not eat everything. You need to maintain flue temps high enough to prevent condensation in the chimney which means 250 internal at the cap which means 400 internal at the stove which not coincidentally is the bottom of the normal range on the Condar flue probe meter. I can keep an active glowing cat with much lower internal flue temps but must give up some efficiency to prevent a nasty chimney.

Woodstoves are not meant to be condensing furnaces!

 

I see in another forum where you were concerned about the accuracy of the Condar probe. Has that been resolved, or is it a non-issue for you now?