Using a Dragon Heater Shippable Core for your rocket mass heater makes construction faster, easier, and your heater's performance will be superior to what you can achieve using traditional approaches. A Dragon Burner will outperform a traditional rocket heater, because it is made of superior materials, has an optimized (patent pending) burn tunnel, and utilizes secondary air channels for complete combustion.
Countless people of have put days of labor into their rocket heater project only to have it fail. This happens because the rules for sizing the various parts in relation to each other have been difficult to understand and unsuitable materials have been substituted for the proper ones. By using a Dragon Heater, you are assured the engineering is right and it will last. You don’t want a heater to fail when you need it most.
The dragon burner comes in a few pieces that are quickly assembled. Add a steel drum, a base for it, and a bench or bell, and you're done.
With a shippable rocket heater core, or Dragon Heater, it is now easy to build rocket heaters without cob. The exterior shell for your heater can be made of steel, or masonry material which can be tiled or rock faced to suit any decor. This means you can easily build rocket heaters where clay may be harder to find or transport. Moreover, your finished unit will probably weigh a lot less than it would constructed mostly from cob.
The plans and kit section shows you how to build a complete rocket heater in only a few hours, or build a complete Rocket Heater with your choice of tile in less than a day.
Traditional rocket mass heater combustion chambers are built with antique red bricks or fire bricks. To have a clean and efficient burn, the combustion chamber (burn tunnel) should be as hot as possible. In other words, the burn tunnel should be constructed of insulating material. Heat retention materials, such as fire bricks or red bricks pull heat from the combustion process. Fire bricks are suggested because they are readily available and withstand the very hot temperatures of a burn tunnel, but they, unfortunately, rob the combustion process of heat, making it inherently less efficient. The Dragon Heaters shippable core is made from special insulative cast refractory material which will hold up to the high temperatures without robbing heat from the combustion process.
This burn tunnel, developed by Peter Van den Berg has a number of unique elements that make its performance superior to tunnels constructed of bricks. (You can read more about its development here.)
When combustion begins the gases traveling down the burn tunnel are invariably slowed by friction along the side walls (called laminar flow). The Dragon rocket heater core has two specially designed wedges which disrupt laminar flow. The gases are forced to return to the combustion flow, insuring a good mix and (virtually) complete combustion.
Further turbulence is induced, without electricity, by a pair of vortex spiral shapes at the end of the burn tunnel.
A secondary air intake is included just after the feed tube. This channel is essential for more complete combustion as well as preventing back smoking. Although most of rocket mass heaters do not include such a secondary air intake, it has been shown to greatly improve the performance of any rocket heater. The air is preheated by the metal feed tube so as to not rob the combustion process from the introduction of cold air.