Airflow in NC30?

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bluedogz

Minister of Fire
Oct 9, 2011
1,245
NE Maryland
So, this thread made me think: https://www.hearth.com/talk/threads/what-do-your-coals-tell-you-about-your-fire.121083/

Normally, a full load is good for about 6-7 hours before I need to pull coals to the front, clear space around the doghouse, and load again.

Lately, when I do that, I find a lot of larger unburnt coals. This would make me suspect the wood BUT 1) wood is 2-year CSS hickory & BL mostly, and 2) the chunks I am finding are almost exclusively at the back of the firebox, while at the front there's nothing but powder.

Can anyone give some guidance on how air circulates through the 30's firebox? Is the rear of the box late in the cycle so that those coals get less air?
 
Pretty much I think your primary air intake is the air going over your glass.
 
I've scoured the manual for this... I'm hoping to learn more about where and how the air comes into and goes to.
 
There are 3 sources of air for the Englander 30. The primary air comes in through the 3" hole at the bottom of the stove. This air enters the combustion chamber as the "air wash". When you open the door you can see a flat plate across the top of the door opening.

The secondary air comes in through a 1.5"x1" rectangular hole at the back of the stove, near the bottom. The air enters the large rectangular box at the back of the firebox and goes up to the secondary air tubes.

The third source of air is the "doghouse" air which enters through two holes under the front of the stove. There is one on each side near where the legs would go. They are hidden and are inaccessible if you have the pedestal installed. The air then goes into the firebox through the doghouse, the doo-hickey front and center down at the bottom of the door opening that blows air at the fire.

The wood at the back and sides of the stove are the last to burn because all the air is up top or in the front.
 
Makes sense... so, how does everyone with a 30 deal with this? Is everyone raking coals and I'm not? Or am I thinking too much?
 
That long slow burn front to back is common with modern, square fireboxes. Are you loading E/W or N/S?
 
N/S normally.
Sometimes, I will throw a small split E/W across the back of the box, then load N/S on top of that and the coals raked to the front.
 
It all sounds normal. I open the air up during the last hour of the burn. Then in 30 minutes I rake the coals forward, put a small stick on them and let them burn down for 30 more minutes. Reload and repeat.
 
I noticed the same "problem" with the nc30. The bottom back of the firebox doesn't burn down very well. After the front stuff burns off, the stove cools since that lower back stuff doesn't burn very well. I am not concerned with which wood burns when but if the heat output falls off then I have to reach in there and pull that part of the fuel up so that it will burn.

This problem is particularly bad after cleaning the ashes out. It seems that a larger ash bed encourages proper combustion of the back.

The solution is likely to pull the back fuel forward and reload sooner.

On my BK stove, also a square, the airwash burns out the center of the load front to back and then the sides burn completely. Almost like two separate fires.
 
and in these sub, sub freezing temps there is limited chance of complete combustion prior to reload -just too cold to wait it out. Rake forward and put small splits on the heavy coal bed with the primary open and you extend the usable heat while burning down those coals expect this in these conditions no matter how dry your wood is.
 
and in these sub, sub freezing temps there is limited chance of complete combustion prior to reload -just too cold to wait it out. Rake forward and put small splits on the heavy coal bed with the primary open and you extend the usable heat while burning down those coals expect this in these conditions no matter how dry your wood is.

The deal is that these back logs aren't even coals, they are unburned fuel seemingly starved of air. They burn well when pulled forward though.
 
Huh?? I never get that no matter how I load the stove. More research will need to happen for sure.
 
I handle the stuff in the back differently. Instead of pulling a large bunch of the stuff forward, I put the small split on top of the stuff in the back and give it some air and burn it down. Reason being the heat has to travel forward before it goes up the pipe.
 
The deal is that these back logs aren't even coals, they are unburned fuel seemingly starved of air. They burn well when pulled forward though.

In my case, they are unburned chunky coals, often mixed with glowing embers. So, I think I might agree that they're not getting enough air.
 
I always get a complete burn if I leave it alone, like with an overnight burn. The back just takes longer.
 
I always get a complete burn if I leave it alone, like with an overnight burn. The back just takes longer.

For me, that's generally not the case... incomplete burn at the rear even in the AM.
 
What I've been doing lately, due to the weird warm weather and the need to only burn a few splits at a time...

Push all the coals to the back, then put the three splits on N/S, leaving a good sized hole in front of the doghouse. Reasoning being that it gives the smoke more time to go over all of the secondary tubes. Seems to get the secondaries going faster than when I pull the coals forward. :shrug:
 
What I've been doing lately, due to the weird warm weather and the need to only burn a few splits at a time...

Push all the coals to the back, then put the three splits on N/S, leaving a good sized hole in front of the doghouse. Reasoning being that it gives the smoke more time to go over all of the secondary tubes. Seems to get the secondaries going faster than when I pull the coals forward. :shrug:

"Weird warm weather"? Where exactly are you? It's 13 degrees here.
 
"Weird warm weather"? Where exactly are you? It's 13 degrees here.

South-Central Oregon. Highs have been in the mid 40s <> We need the snow the rest of the country is getting, or we may make nation-wide news again next summer (Klamath Basin water shutoffs).
 
Discription of air intakes off a bit. Rear of unit 3" ( also oak connection ) primary air fed into box through dog house, secondary feed is a rectangular hole close by the 3" intake, air wash from holes by legs air wash and secondary air feeds uncontroled, only the 3" intake is controlled by the damper rod below the ash lip.
 
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