Wasting wood

Your stove is designed to run off of secondary air, not primary. In other words, closing the primary air down allows the secondary air to start sucking more so it can burn the smoke. If you are leaving the primary half open, you are consuming wood rather than just smoke. If you were to map this with infrared you would probably see that you are doing a good job of heating your chimney and losing a lot of your BTU's from your house.

That is what heating is all about, getting as much BTUs that you can out of your appliance. That is where efficiency comes into play. The other thing you need to remember is that the more air you feed the stove, the more air that is depleated from your house. Which means that more cold air has to be sucked into your house.

nmaho said:

I usually don't close down the air to less than half, I like to keep it hot and not create creasalte how much wood am I wasting? At night I will load up at 10pm and still have hot coals at 5 am when I get up,plus I don't like dirty glass if I choke down.

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How seasoned is your wood? Do you know? Do you have a moisture meter?

nmaho said:

plus I don't like dirty glass if I choke down.

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If you're getting dirty glass when you close down your stove, most likely your wood is not at ideal MC. How hot is your stove top temp before you start closing it down?

The primary air control allows the draw from the flue to pull air through the stove. Everyone's flue draws differently, so everyone's primary air control allows different amounts of air for a given setting. Your stove set at half air might be similar to another guy's stove set at 1/10th; you shouldn't necessarily try to copy somebody else's settings.

Most days my stove doesn't burn well with the primary air closed all the way, ,so I leave a little primary air (plus the doghouse air which is primary air I do not control). In general I try to burn cleanly and not put out too much smoke, which means burning hot. This is good for air quality and helps keep the chimney clean.

However, I'd say the best way to alleviate your concerns about creosote in the chimney is to learn how to inspect and clean the chimney yourself, and do it often enough that you are confident your chimney is clean. Inspecting the chimney is really nothing complicated at all - you just look in there. It doesn't take long to learn what amount of accumulation in the chimney is ok and what isn't. Cleaning the chimney is a little more involved, but I think most anyone who can do stuff like trim shrubs or paint a wall should be able to clean a chimney. If you don't have a friend who can teach you, maybe you can hire a local chimney sweep to do it and show you how in the process.

I've had the odd occasion where I'm shutting down primary completely and getting a great burn. Usually when I load up with primo maple or yellow birch that's been on the stack for 2 or 3 years. But more often than not the primary is open just a bit. Manufacturer actually reccomeds this as a guideline, but like Wood Duck says, everybody's sweet spot might be a bit unique. Also don't be shy about "wasting" wood while you figure out yours.

BigCountryNY said:

If you're getting dirty glass when you close down your stove, most likely your wood is not at ideal MC.

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I don't know, my wood is 15% and if i close my air all the way i'll have dirty glass in the morning without fail.

Even with a hot fire? If the fire is hot and the wood is dry it should be good. My glass only gets dirty if the fire is smoldering instead of burning. Air wash performance is another variable though.

Very good point. Since mine is shallow and loads E/W I can definitely close it all the way down without a problem. With a N/S firebox and the way EPA stoves are designed to burn, I can see how that could happen easily when closed all the way down.

Every stove is different. I can't close min all the way. Its sweet spot when it's good and hot is between 1/8 and 1/4 open on the primary. Any less and the burn visibly suffers and temp gauge drops. Experiment until you find your sweet spot. It shouldn't take more than 5 or 6 good burns to get it dialed in.

Same burn, taken 1 minute apart. 15 minutes into a good hot burn with dry hardwood (Ash or Elm) and the stove temp at about 500 degrees
Primary air at 25%:
Pimary air closed:

BrotherBart said:

With a shallow firebox you can probably get away with closing it down withhout smoking the glass. But with a deep firebox you are going to smolder the stuff in the back late in the burn and with the primary closed all the way there isn't enough airwash to overcome the smoke and you crap up the glass.

With every Jotul stove I have ever seen they loved about 1/4 air. In fact so does my big Englander.

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Not my Jotul . . . with wood seasoned for a year or so I may run it at 1/4 . . . but the well seasoned (two or three years) I am running now I routinely shut it down all the way . . . and last night I had to place the tin foil over the air inlet to close off the air completely (well for the secondary air) as it was getting mighty hot, mighty quick (I am now seriously thinking about getting a damper). Woke up this morning to plenty of coals, warm house and clean "glass" (other than some fly ash which is normal after several days of burning.)

I usually close my air all the way down for a good lazy burn with good secondaries..stove cruises round 500 -520..my glass stays pretty clean..maybe bottom edges get dirty...if i need more heat ill open the primary a tad