Quantifying Results

[kevreh]

I'm trying to figure out if the performance of my Napoleon insert (model EPI3) is "normal". I hear stories of people getting much better results than I do (with other inserts). For example, some folks say their living room heats up to 80 (mine, maybe 74). They also say it can heat the rest of the house (we have a split level, so maybe this isn't reasonable without fans).

Of course, every house is different. But still is there a way to measure performance? Below are my details, fwiw.

- Napoleon EPI3 wood burning insert, with ~22' of ss liner, terminates through a ss sealed cap.
- Insert is on a 600sf level, half below grade, of our split level house
- Chimney is exterior brick.
- While I didn't use a block-off plate, I did pack roxul around the liner where it goes into the flue. While not 100% air-tight, I never feel any draft or cold air.
- When the fan comes on, you really don't feel air movement unless your 1-2' in front of it.
- Wood....I try to use locust, fully cured (no hissing sound when burning). I can't really say I keep the insert loaded, so maybe I'm being to tight stocking it with wood. Problem is my pieces are 16-22" and only go in left-right. So hard to stack them.

Thanks!

 

[begreen]

Yes, house design, construction and location vary a lot and stove designs are different Lots of questions. How much wood at one time is going in the insert for a full loading? How robust is the fire? Are you able to close down the air most of the way or at least until it is about 25% open? Dod you see good secondary combustion above the wood?

 

[snavematt]

I don't know your stove I have an Explorer 2 and I am heating my house of around 3800sqft to 70-71 with my stove 350 degrees. I have a pretty open set up, but the natural convection works pretty well. My blower on the stove when on you can't feel from very far away. I use poplar, locus and oak. Here is a crude drawing of the floor plan and my stove








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[kevreh]

I don't know your stove I have an Explorer 2 and I am heating my house of around 3800sqft to 70-71 with my stove 350 degrees. I have a pretty open set up, but the natural convection works pretty well. My blower on the stove when on you can't feel from very far away. I use poplar, locus and oak. Here is a crude drawing of the floor plan and my stove

Yeah, I think with the open stove design a LOT more heat is radiated back into the room. BTW, when you say you heat your house, are you talking 24/7?

 

[kevreh]

Yes, house design, construction and location vary a lot and stove designs are different Lots of questions. How much wood at one time is going in the insert for a full loading? How robust is the fire? Are you able to close down the air most of the way or at least until it is about 25% open? Dod you see good secondary combustion above the wood?

Hmmm, hard to say how much wood. I typically throw another medium sized log or two. I don't want to burn through them too quickly, so I don't load the box up, maybe 40% full at the most. Which leads to your next point. I usually keep my air damper/valve at 75-100%. Does keeping it at 25% mean more heat is put out? Wouldn't more heat be generated with it fully open, or is it letting too much heat go up the flue. I really haven't experimented with it being choked down that much.

Fire's robust, but again, it should be with damper fully open. If I close it to 75% OPEN, I get a nice, slow rolling fire. I don't know what to look for in secondary combustion. ???

 

[begreen]

It could be your burning technique that is holding back the stove. As long as the wood is dry and draft is sufficient, the more you close the air control down the more the draft will pull air from the secondary combustion ports. That in turn leads to more complete combustion of the flue gases and a hotter stove. It sounds like you need to try loading the insert up to maybe 75% and after the wood gets burning nicely, incrementally start reducing the air, maybe 25% at a time, then wait for the fire to regain strength and reduce the air again. Depending on the stove, the wood and the draft you may be able to eventually over 15-30 minutes, close the air almost all the way. If the fire starts smoldering then that is too little air, but a lazy flame is fine.

Take a look at this video for some tips on burning in an EPA stove
http://woodheat.org/wood-heat-videos.html

 

[snavematt]

Yeah, I think with the open stove design a LOT more heat is radiated back into the room. BTW, when you say you heat your house, are you talking 24/7?

Not 24/7 since I'm not comfortable enough yet running it while not home all day, the FA stuff stays at between 64-65 and I can get the house over 70 in a few hours, I burn over night and nothing else turns on overnight



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[Slacker]

Since you have an insert you cannot measure your stove top or flue temps. On my Drolet when I do a reload, I get stove top temps of 600 or more with the air 100% open. This gives me a flue temp of 600 or more. When I start cutting back on my air I can see the flue temps drop. By the time I'm done adjusting the air I am usually around 15-20% open with a stove top of 500-600 and flue temp of 275-325. This equals slower burning and less heat going out the chimney and into the house.

 

[iceman2424]

I get the most heat from my stove (same as yours, epi3t) when I pack it to the brim, fully loaded, then damper down incrementally...just like @begreen mentioned above.

After 30 min, try fully closing...you should see the secondary combustion you asked about...but my experience has been in order for those reburn tubes to rock I've gotta have a full firebox.

 

[begreen]

I get the most heat from my stove (same as yours, epi3t) when I pack it to the brim, fully loaded, then damper down incrementally...just like @begreen mentioned above.

After 30 min, try fully closing...you should see the secondary combustion you asked about...but my experience has been in order for those reburn tubes to rock I've gotta have a full firebox.

What is the air control setting after 30 minutes?

 

[iceman2424]

Here is a video I took last night...I figure this is what you'll want to look for re: good secondary combustion. I've been burning nonstop here at the north pole...I mean Michigan.

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[venator260]

my experience has been in order for those reburn tubes to rock I've gotta have a full firebox.

This seems to apply to all stoves with tube technology. To get good secondaries and a nice long cycle with good heat, my 30NC has to burn down a good way and then get stuffed pretty full with just a bit of air space at the top. Then close down in increments like has been discussed. Try to load on too many coals (not as many new splits will fit) or less than half full, and results are not as good.

 

[iceman2424]

What is the air control setting after 30 minutes?

It depends, I typically go anywhere from 0% to 50%, but never more than 50%.

 

[begreen]

That's helpful info and video iceman.

 

[kevreh]

Here is a video I took last night...I figure this is what you'll want to look for re: good secondary combustion. I've been burning nonstop here at the north pole...I mean Michigan.

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WHAT the??? So, is that what secondary combustion is? Where it looks like fire comes out of the top tubes? Can't thank you enough for posting, video worth a thousand words. It looks like its not that full, maybe only a couple logs. Is that right, or just the way it looks? Also, What % would you say the air control is at when you shot the video?

Also, if I could ask one more question since you have the same model, how big of an area are you heating and how warm does it get?

Last night after I had the insert burning for a few hours I throtteled the air control down quite a bit, almost all the way. I didn't get secondary combustion, but the fire was sort of slow and lazy.

THANKS!

 

[begreen]

Last night after I had the insert burning for a few hours I throtteled the air control down quite a bit, almost all the way. I didn't get secondary combustion, but the fire was sort of slow and lazy.

Yes, that is what secondary combustion looks like. It could be that your wood is not quite fully seasoned. Try adding a few 2x4 cuttoffs between the log layers. Try 12" long pieces and put them in at right angles to the logs, spacing them about 3" apart. Maybe cut down the air a little less, say to 25%.

 

[iceman2424]

WHAT the??? So, is that what secondary combustion is? Where it looks like fire comes out of the top tubes? Can't thank you enough for posting, video worth a thousand words. It looks like its not that full, maybe only a couple logs. Is that right, or just the way it looks? Also, What % would you say the air control is at when you shot the video?

Also, if I could ask one more question since you have the same model, how big of an area are you heating and how warm does it get?

Last night after I had the insert burning for a few hours I throtteled the air control down quite a bit, almost all the way. I didn't get secondary combustion, but the fire was sort of slow and lazy.

THANKS!

No worries, man. In that video, there are at least 3 splits in there, and the air control was probably set at fully closed, or 10% at most. I don't ever put fewer than 3 splits in on reload...depending on the size of the split, I'll go 3 to 6 pieces of wood. You have to really feed this stove with copious amounts of fuel in order to succeed. I figure generating heat is like anything else in life...you get back what you put in. Feed that baby what it wants, and lots of it!!

And like @begreen just said, seasoned wood is the key to all of it. I have some seasoned and some semi-seasoned, and the fully cured wood gets the stove absolutely cooking, while the other stuff doesn't work quite as well.

The primary area I'm heating is about 400 square feet in all. A living space and an adjoining kitchen. This is the area of the house we spend most of our time in. My house is 1,500 square feet but the stove is placed in an addition toward the rear.

While I don't have a thermometer in the heating area, I'd estimate it's around 75-77 degrees in that addition. It's all relative, though - the addition has crappy insulation (if any) and windows and doors that were probably put in around the time Kennedy was president, so I consider those temps a raging success.

My furnace thermometer, which is basically on the other side of my house, will tick up one or two degrees over what I've got it set at during really cold snaps (like now). When it's 30-40 degrees out, that thermometer will climb from 67 to 72 pretty easily. Also a success, in my mind.