Rocketstoves in all their forms are very interesting.

I built a RocketStove Grill this summer. Fun to cook on.

A local energy group is currently building a "gasirockifier" - it is a combination of rocketstove and gasifier to be used as a boiler. The fire to water heat exchange area is double-walled, welded steel tubes, one inside the other. Essentially, it's a big water jacket.

I would think a drum-within-a-drum would be a simple way to create a rocketstove with water-heating capabilities.

Isn't a natural gas water heater just a big drum with a tube up the middle? I wonder if an old gas water heat COULD be easily modified into a rocket boiler?

I did a websearch for "gasirockifier" and couldn't find it.

Is this project on the web anywhere? What's the current status? I'm interested in a rocket stove boiler, for heating water for use in my in-floor heat tubing.

No, the "gasirockifier" isn't on the web anywhere that I know of. It's more a group of hard-core, hands-on kind of guys, but other than taking some digital still photos, none of them are great with blogging about the projects.

Next time I am over there, I will have to take some photos and maybe do some video interviews.

I did recently post my Rocket Grill over on Instructables if anyone is interested.

Thanks, that would be much appreciated.

I've already printed off a copy, and put it on my todo list.

Are round burn tubes a lot better than square or rectangular burn tubes? The cuts would be a lot simpler for the feed-tube-burn-tube connection with rectangular or square tubing.

I hadn't even thought about using square tube. I guess it's just that I have access to a fair amount of round tube, old water heaters and that sort of thing.

Some square tube would be special order and cost money.

I would imagine that round would be SLIGHTLY better than square in terms of airlflow going through with less turbulence.

The other thing is that if you want to wrap soft copper pipe around the outside of a tube, square wouldn't work so well.

I got the idea when I saw the Heavy Duty Grover Stove on the Internet:

Heavy Duty Grover Rocket Stove

With a square tube the pipe could be placed in the tube filling the corners making it more of a round shape but a small heat shield might need to be placed just below the bottom corners of the pipe so the elbows or bent pipe is not getting over heated.

This is cool - a mini rocket stove made from soup cans, concrete, and perlite. He designed it to be portable and use in his fireplace. It is still in progress, but it looks like it will be a pretty sweet little setup. With such a small burn chamber he could easily connect it to a 3" flue. With the firebox heating water, it may be a viable water heater.