Duane Hylton

A 6000 square foot shop is more than likely going to need a lot more than a radiant heat supply. Radiant heat works well in a well insulated fairly confined space. Radiant heat transfers at the rate of the fourth power of the difference in the two temperatures. That's the good news. Unfortunately it diminishes at the square of the distance. That means unless there is an extreme difference in the temperatures the distance becomes the more important factor.  The room sized Liberator will do little to affect the comfort level in your shop. I recommend you look up Eric Hroboni's massive rocket furnace, I think he calls it huge, that heats a 3000 square foot uninsulated greenhouse in a cold part of New York.

CJ welcome to Permies.

Check out this thread: Green house rocket stove thread

Sounds like the same sort of application that Eric has. You can PM me if you want more background, though I only check in a couple of times a week. Eric is too busy with his business at the moment. Be patient and you can get help. Eric also posted a couple of videos to youtube so you can search his name there as well to see it in action.

Mike Haasl wrote:Cool, so you're sucking air and blowing it at the same end of the greenhouse.  That probably gives you a nice gradient of heat so it's warmer on that end and cooler on the other end of the greenhouse.  Running one of those ducts to the other end might even the gradient out (for better or worse)...

Yeah, But this way he's preheating the combustion air. But you are right about a full run to the other end would probably help.

Here's the new video

It's a hand.

Another question, (I know I'm a pest), if you've had the bell open since you started using this stove in a big way, did you find much ash on the floor of the bell?

I'm totally fascinated by your stove because it is the first one I've seen that can heat almost 3000 sq ft and with marginal insulation by typical home building standards. I wish some engineer out there would calculate the energy required for that many cubic feet. Also, yours isn't really a Rocket Mass Heater but just a Rocket Furnace because you don't really attempt to store any of the heat in a mass but rather are heating the entire envelope. But still you don't waste much because the stack temps on the chimney are very reasonable, not much escaping to the outside.

Question for you Eric, it looks like you have a short but significant burn tunnel between the firebox port and the riser. What are the dimensions of the tunnel and why did you build it this way? Ok, so that is two questions.

That would make one awesome pizza oven, perfect arch style. I haven't looked but a furnace door from one of those outdoor hydronic furnaces might fit the bill as they are made to take quite large logs. And if the air intake is relocated higher you won't need the grate in the bottom either. Simple is better, especially if you have so many to make and feed. Your summer is going to be busy, but fun.

Eric, That video is great at showing the size and scope of your ROCKET stove heater. That's like the Saturn V compared to the Atlas II that the rest of us work with. The thermometer pics I assume are the sides of the bell, but the small window could use some explanation. It looks really hot wherever it is.

You certainly have your work cut out to run a producing farm and build several more HUGE rocket stove heaters. I hope you have plenty of help. I'd be there but I'm allergic to NY, old, and fairly busy myself. But I'll be cheering you on from Northern AL.

I would think that a side door may work better than a front door because it would be easier to toss the wood in inline with the long direction of both the fire box and the logs/slabs rather than the short one. The door could be smaller and you might even find a wood stove door or fireplace insert door that would work saving a lot of effort to build one.

I'd also look into putting the primary air inlet above the normal fire height like Peter recommended just so ash doesn't get in the way if you are going to run it for a couple of days at a time if you get the feed design worked out.

A full width ash pan might be in order as well so cleanout can be trivial. I made mine out of 1/16 galvanized and Kast-O-lite 30 LI Insulating Castable Refractory: with a 2"  lip and then just built up the edges leaving the center 1" thick to form like a burmed pond to hold the ash. Just make it so the sides of the pan extend to the exterior walls and are under the insulated portion of the walls so the metal is not exposed to the fire itself. Yours would need to be scaled up to be deep enough to hold enough ash of course. I've been running my stove hard for two winters and the ash pan looks like new even being the floor of the 1700*F  firebox/burn tunnel for up to 5 hours at a time. A couple of handles welded to the front and you'd be able to clean the ash in less than 5 minutes.

You might look at the way they light TLUDs to make start up a little easier. Top lighting of fires is done extensively in places like India and can be quite efficient. Just requires a slightly different technique. As for me, I'm a big fan of charcoal briquets saturated with Kingston lighter fluid; easy and fool proof.

Please keep us up to date on your progress. And thank your wife for the taping of the video.

It sounds like you guys had a great time and learned a lot. Thanks for taking the time to get with Solomon and bringing us up to speed. Your new tool sounds awesome, good luck getting familiar enough to be one of the "experts".