Advice on using an EPA stove?

[Mustang71]

So at what point do you leave the secondary burn alone. Do I want the tubes firing off and it burning violently or just burning blue at the top of the stove or a mix? It was holding 450 and burning blue right above the wood but not firing off and then I lightly touched it and it started losing heat and then I lost the secondary burn.

 

[Mustang71]

I run an NC30 really hard to heat a shop building. Added a convection deck and bigger blower. I think you're babying it. I like to run this thing at Stove top temps of 700-750 with full loads of dry PNW softwoods that only last about three hours. I measure flue surface temperatures on my single wall flue and like to hold 300-400 when I want heat.

The NC30 is a 3.5 cubic foot firebox which is about the same as the drolet tundra furnace.

Fill the thing to the roof with 3-5" splits of dry fuel and run it hard. I am never able to fully close the intake damper. Mostly it's at about 50%.

This is sort of what I see that if the damper lever is in past the pan below the door I have issues. I'd run it hard if I knew how to lol

 

[Highbeam]

This is sort of what I see that if the damper lever is in past the pan below the door I have issues. I'd run it hard if I knew how to lol

If I had to tell you my one best trick to getting heat from this thing it has been to fill it up with 3-5" splits and hold 400 flue surface temperatures and ignore everything else. No door open burning, that just blows your heat up the stack. Load north to south and it really helps to have a "tunnel of love" where there is a path for air from the doghouse hole to rush to the back of the firebox.

The glass will self clean, the secondary tubes will glow red. My shop and stove are often at 40 degrees when I start the fire. No problem.

This particular stove seems to burn much better and hotter after at least an inch of ash has accumulated on the firebox floor.

This is a long thread so I'm just kind of spouting off ideas and things that work for me with my NC30.

 

[Deleted member 150358]

My guess is something like this.

 

[Mustang71]

I'm open to any ideas and I'm not trying to baby the stove. So tomorrow when I have a burn like that I'll leave it alone.. I actually laugh a bit because the manual says not to over fire the stove and I think about the daka the paint is white the steel is cracked around the door and that was all it's own doing. I cant figure out how to over fire this thing. But I do know with the daka it didnt make much heat with just splits I had to mix in pallet wood to get it to crank so maybe I'm over thinking the wood a bit. I'm feeding this thing premium wood and not getting premium heat. At this rate I'll be burning more wood instead of less.

I will say tonight I loaded bigger splits on the bottom and I ended up with 2 tunnels and a bridge of wood on top and the back was burning for the first time ever. It didnt burn out quick like when I loaded the bottom with small splits so maybe tomorrow I wont have to shovel ash out.

I'm learning but wtf its like 8 degrees but I'm not using propane. The wife is getting mad because I'm in the basement all night and she's watching the kids.

 

[Deleted member 150358]

Sounds like you need a babysitter ~n~ tend to mama for a night out!

 

[Mustang71]

Sounds like you need a babysitter ~n~ tend to mama for a night out!

I will say this weekend while the kids were napping I was watching a stove and not spending "time" with mama...

 

[Del_]

Our 15 year old Jotul F600CB taken just a few minutes ago from here at the computer:



A shot of secondary burn tubes from a few years ago:

 

[Mustang71]

I had this

Then I closed it more and had this

Then closed it a bit more and it went blue and lost heat.

 

[Streblerm]

I don’t close the draft down all the way unless I’m worried about overfire. I leave it out 1/4-1/2”. Usually I let it get up to 5-600 degrees before I close it down although with the super dry wood I’m burning this year I’m finding I can close down earlier and I don’t need the draft wide open to get going.

 

[Highbeam]

I had this View attachment 720549

Then I closed it more and had thisView attachment 720550

Then closed it a bit more and it went blue and lost heat.

Mustang, you are not filling it up. That's just a half load. You need to stuff that thing with wood and quit closing the draft so far. Let it eat! Leave it like the first picture.

Last night I had a nice NC30 fire and shot the stove next to the door with an IR gun, way over 600.

 

[Highbeam]

I tried to photograph the "tunnel of love" that really seems to help this thing rip. You'll also notice that I stack wood in there like hot dogs to the roof. Seriously, fill it up and let it eat.

My lowest cruise setting, 19 foot vertical chimney, is with the tip of the spring vertically under the forward edge of the ash tray.

 

[Mustang71]

Ok so the idea is not to cut the primary as much as possible. I read a lot of stuff saying to keep cutting down the primary air in steps and a violent secondary burn is a waste of wood but none of that has been working for me. Tonight I'll close the primary air a bit and not touch it after that.

 

[Mustang71]

So it was up to my target temp of 68 in here in about 2 hours but I also cooked an entire load of wood and I packed it like hotdogs.. The temp said 550 which if you are blowing 68 degree air past it I would think it's probably some where above 600 stove temp. I only adjusted the damper once. I threw a few pallet chunks on and a log and it was right back to cranking. It's like 10 out so it's doing a good job. Tomorrow I'll try to cut the air a little more because being a furnace you are not radiating the heat but mixing it. I'm trying to cut back on wood and propane consumption. So if I could get to 68 by 8 o clock instead of 630 in 10 degrees I would be further ahead in the long run.

The input is very helpful without it I'd still be running 300 degrees and hanging my head in shame. Now I wish the weather would cooperate because I haven't started a stihl in months.

 

[Highbeam]

Ok so the idea is not to cut the primary as much as possible.

Not when you're cold! When making big heat your stove will be eating lots of fuel and be running at higher intake settings. Once your home is up to temperature you can reduce the primary air to stretch out the burn time.

 

[brenndatomu]

Have you verified that the baffle(s) are properly in place? Easy to knock out of place during install, or even just loading wood. Makes a big difference in the way it burns if the baffle is out of place.
Also sounds like your wood may not be optimally dry. Once the fire and secondary burn is well established, you should be able to cut the primary air back quite a bit (slowly, in stages) without snuffing the fire out. Once the primary air is cut back the stove pipe temp will drop, but the air temp coming out of the furnace will slowly go up.
As far as heating your house with a 850 CFM blower feeding a 8" pipe...it'll work...Kuuma uses one 8" pipe on their VF200...and only a 500CFM blower...rated to heat 3000 sq ft...which may be a bit optimistic, unless the house is well insulated...but it did fine with our 2400 ft last winter, on all but the coldest days....on those few days it needed a lil boost from the Drolet 1400i in the fireplace.
You'll get this sorted out...seems like there is always a steep learning curve when you get a new stove (furnace)
The only thing that worries me is that you said the old furnace was white from overheat...that is usually a sign that your draft is too high, or you are running too hard to overcome a large heat load.

 

[Mustang71]

Last night I got it going on pallet wood then up to 500, which didnt take long, then I threw half the wood on that I did the night before and let it go for a bit. I was able to cut the primary air by a lot more and getting over 500 degree heat with the temp going up. A few hours later I threw one log on top of what was there and it started ripping again and still cranking the heat. Last night was the warmest night I've had from this furnace and the most efficent. It never died out because I didnt mess with it until it was at least 450 and I had good secondary burn all night.

The daka had zero control over the heat setting. Put wood in and it might burn it up real fast or it may bearly burn it until its adjusted right. If it was running hot all I could do is put more wood in to cool it down. The bimetal draft control did not work it was wide open or closed once the fire was going.

 

[moresnow]

Sounds like your getting on top of this. Hopefully you can get the operation ironed out, so you can address directing the ducting. Guessing its not hooked up yet? Unless I missed that?

 

[Streblerm]

Sounds like you’re getting it. You’ve arrived at what I do For long burns from a cold stove. Start it about an hour before leaving or going to bed and get it good and hot 5-600 then right before I leave/go to bed I put in another piece or more and close the draft down most of he way. That’s how you get decent heat for a long period. It really takes two loads. The first one heats everything up and the second one provides for the slow burn.

 

[Mustang71]

Sounds like your getting on top of this. Hopefully you can get the operation ironed out, so you can address directing the ducting. Guessing its not hooked up yet? Unless I missed that?

Its hooked in but I'm using my lp furnace to circulate the air which I dont want to do. That uses a lot of electricity and puts more wear on the furnace and living in the country the power likes to go out a few times a year. My generator wont run my lp furnace and I'm going to need heat.