Design help needed

[Cbb1900]

Wow, I never expected to find so much wood stove info, being from texas I guess it isn't really a part of my culture or heritage like it is in a lot of places lol..

Anyway, being a bit over whelmed with info, I figure I'll just outright ask for help.

I found a couple of pieces of concrete drainage culvert//pipe, it's dimensions are 4ft x 1ft about 1 and 1/2 Inch thick, and I have 2. I decided to use one to make a wood heater for my little outside area, which consists of a poorly built, super drafty garage//work area. Well little did I know there's a science to building one that actually works, I thought I could pop a chimney on that badboy and be warm n cozy. Not the case. I can stack the tubes if need be or add a fan, which I've already been toying with, I rounded up some old power supply fans, and accidently heat tested a couple.. Turns out they don't pull the air very well, but they do fine pushing it lol.. I could add vents etc, currently I only have a 2inch chimney hole about 1ft from the end of one of the tubes, anything to get this thing to quit smoking me out lol..

Thanks in advance 🙂

 

[armanidog]

"concrete drainage culvert//pipe"
I would worry about any high heat cracking the pipe. If you have a decent fire, temps could go up to over 800-900 degrees F.




A barbeque would put out less heat.

 

[Cbb1900]

"concrete drainage culvert//pipe"
I would worry about any high heat cracking the pipe. If you have a decent fire, temps could go up to over 800-900 degrees F.




A barbeque would put out less heat.

Well that was not helpful at all lol... I mentioned being smoked out, right? So yea.. Ive already burned a few logs.. It'll be fine,, thanks for your input though....

What I'm looking for is maybe someone to draw me a Pic of how I could make it work lol.. Something like this

 

[Cbb1900]

Problem with using this design is not enough inner diameter, so I was hoping there was another way, like maybe if I did the chimney and flu a certain way with one cylindor, maybe it would be "good enough"?? I dunno..., just thought I'd see if anyone had any ideas really..

 

[Easy Livin’ 3000]

Don't bother. It's going to disintegrate in short order. Spoken from direct experience. That concrete is not engineered for heating and cooling. Just because it hasn't happened yet doesn't mean it won't. Go ahead and waste your time and energy on this bad idea, and see for yourself.

 

[Corey]

Yes, normal concrete will crack, spall, or worst case explode in the intense heat of an actual fire. Might get away with it for a barbecue pit, but an actual wood stove with secondary combustion could pretty easily get up to 1000-1300F or higher. The water you mix to make the concrete doesn't 'dry out', it gets incorporated into the chemical structure of the cement. The heat converts that back to water and the internal steam pressure results in big problems. Nature of the beast... not something you can work around. Possibly if you completely lined with a bunch of insulation and firebrick, but in that case, you're just building a second stove already.

You'd likely be much better off to buy an old wood stove, or start with some form of steel container, then build your stove from that.

Also, the design pictured above is not really good for secondary combustion. The idea is to bring in the fresh air, heat it extremely hot, then inject the air right at the hottest point of the fire. Ideally, a super insulated firebox, have the main combustion, inject air for secondary combustion and even more heat, THEN all the combustion/exhaust gas spills into a heat exchanger to get your heat out. The way the plan shows injecting air into the top burn chamber, it will already be too cold to do much good.