Secondary Air Distribution System

I should point out mine is not a Clayton/Hotblast but an old box stove from the 70's. But I thought I'd add what I did for an adjustable air inlet as that will work on any stove wanting an adjustable inlet. You could certainly make a better looking cap and I think a teardrop cover like the Chubby stove uses would look good.

franco b wrote:

Stoker6268 wrote:I thought with Clayton/Hotblasts it was good to block the secondary air by putting insulation between the liners thus more air through coal bed. Why then are you adding secondary air back in via the tubes? Forgive me, im confused...

The first instance is bleeding off primary air. By adding the pipe the secondary air is independently controlled and added at a better place.

Yes, exactly.. With the air passages between the liners (on the Clayton), primary air would reroute itself around the coal bed later in the burn (because of ash build up) which resulted in more secondary than primary air feeding the fuel bed. This is backasswards as to how it should be done. With this arrangement, we can add more secondary air during the volatile bake off and then trim it back later in the burn when there isn't as much needed.

It's all about having independent control of each, primary and secondary air.

I totally agree, and I hate to bring mine into this cuz I know it's going to turn things up, but my over fire air is wide open, and comes in from the ash area, but my liners do not have gaps to begin with they are tight, I think it is a more even spread of over fire air, and even after asking up after 24 hour burns I do not see any problem with the way mine is fabricated, I did it this way so that I did not have to drill holes in my stove, and I believe it is preheated because it is all inside the stove.

hotblast1357 wrote:I totally agree, and I hate to bring mine into this cuz I know it's going to turn things up, but my over fire air is wide open, and comes in from the ash area, but my liners do not have gaps to begin with they are tight, I think it is a more even spread of over fire air, and even after asking up after 24 hour burns I do not see any problem with the way mine is fabricated, I did it this way so that I did not have to drill holes in my stove, and I believe it is preheated because it is all inside the stove.

I think this works for you because the holes in your pipes control the amount of secondary air borrowed from under the fire. The liners in my unit have huge gaps between the liner and firebox wall that pretty much allow any amount I could have coming thru the primary opening to bypass the coal bed.

Your arrangement still forces air up thru the fuel bed because of the limiting of air by the small holes in your secondary air pipes. The only drawback is not having independent control of it. But that's ok, its working.

I agree

Lightning wrote:

hotblast1357 wrote:I totally agree, and I hate to bring mine into this cuz I know it's going to turn things up, but my over fire air is wide open, and comes in from the ash area, but my liners do not have gaps to begin with they are tight, I think it is a more even spread of over fire air, and even after asking up after 24 hour burns I do not see any problem with the way mine is fabricated, I did it this way so that I did not have to drill holes in my stove, and I believe it is preheated because it is all inside the stove.

I think this works for you because the holes in your pipes control the amount of secondary air borrowed from under the fire. The liners in my unit have huge gaps between the liner and firebox wall that pretty much allow any amount I could have coming thru the primary opening to bypass the coal bed.

Your arrangement still forces air up thru the fuel bed because of the limiting of air by the small holes in your secondary air pipes. The only drawback is not having independent control of it. But that's ok, its working.

i think what HB1357 has achieved is the same as what was done with the DS Circulator stoves. a self regulating, preheated, fixed secondary system.

as we have discussed before, and i'm still not sure HOW it works, it works and works well.

steve

Yes it does, it works the same as ANY modern woodstove, they have non controllable secondary air, except this is from outside the stove body, mine just takes the primary air and divides it, weird thing also is that I don't have to run more primary air than before this mod too achieve the same temp.

hotblast1357 wrote:Yes it does, it works the same as ANY modern woodstove, they have non controllable secondary air, except this is from outside the stove body, mine just takes the primary air and divides it, weird thing also is that I don't have to run more primary air than before this mod too achieve the same temp.

I like your setup. It makes sense. No way I could pull it off on mine or I'd have done it.

Thank you, is your stove not firebrick lined?

Yes, fully lined, the bricks sit on top of the grates in front and back. I would have had to cut the grate corners to run pipes down thru so thats not going to happen. However mine decides to work will have to be good enough I guess. I do plan on running wood and soft coal some, and know that the pipes will really help with that. My efel has a cracked grate so had to come up with a heating fix, at least for this winter. My Jr isnt big enough to do it alone in this location, but heats well. I use both stoves when it gets real cold, like now.

I fired the beast up last night and got quite the fire show. It looked like 10 acetylene torches blazing away when the gases hit the 10 holes on each side. I had more flame on one side because that sides firebricks are an inch or so lower than the other. Hard to get a pic thru a 2 1/2" round mica window, but this was the best I got. The firebrick above the flame you see is one of two that are a heat baffle, so when it gets past that it is half way across the stove. The temp shot up 150 degrees very fast when this happened, and the whole stove was blue above the brick. I was wishing I had a bigger window. The pic is not of the fire, but of the air pipe holes above the fire, and they were more blue in color.

Brilliant !! love seeing all the progressive re-engineering efforts around here showing positive results.

With this old technology, maybe we should call it regressive, lol.

That's great, congratulations on the new and improved stove. Have you noticed any differences in comfort or coal consumption?

Very interesting. keep on posting results.
Thanks