Rocket Mass Heaters
A custom-made, efficient way to heat your home sustainably
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Based in Andalucía, Spain
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Please contact through RocketMassHeaters@gmail.com
for a quote for your custom heating solution.
The fire has been the center of family life and a source of comfort, security and community for thousands of years.
This fascination for wood fired stoves and the need for a sustainable, efficient heating source led me to
Rocket Mass Heaters.
What is a Rocket Mass Heater?
A Rocket Mass Heater (RMH) is a modern, super-efficient take on the masonry heater. It was developed to be fairly easy to build, with affordable and on-site material while still being safe and easy to operate. It will bring comfortable warmth into your home at a fraction of the wood-use of a normal stove.
If you have access to a small piece of land, as many in the countryside do, the chances are high you can provide a large portion of your own firewood needs from trimmings.
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The RMH core is an insulated burn chamber where complete combustion is achieved by high temperature, turbulence and ample air supply.
This leads to a clean burn (no smoke, less particles) and efficient use of the fuel (it’s burned completely instead of leaving as smoke).
When the RMH has reached temperature it sucks in air and a “rocket” sound can be heard, hence the name.
The hot exhaust gases (almost exclusively CO2 and water vapor from the combustion) are then channeled into a large mass, which often has the form of a bench. Here the hot exhaust transmits the heat to the heavy materials, which in turn slowly release the heat over the course of a couple of hours, even after the fire has gone out.
Because of the complete combustion there's no creosote and the exhaust can be cooled down without danger, allowing us to run it through the mass instead of out of the house as quickly as possible.
A RMH is always built according to the space that needs to be heated. It can be built in a variety of styles and with a large range of materials, catering to personal taste and the specific needs of the space. It will provide constant, comfortable heat with a fraction of the wood used by a normal stove.
Contact me at rocketmassheaters@gmail.com for further consultation and a quote for your specific heating needs!
Types of Rockets
J-tube Rocket Mass Heater with Bench
The J-tube is the traditional, true and tested engine for a RMH.
The insulated core provides the temperature and turbulence to achieve complete combustion. A metal barrel sheds some immediate warmth while the connected bench stores warmth for hours, extracting a maximum of heat from the exhaust gases, and providing a cozy hang out spot.
We build the core (feed tube, burn tunnel, and foundation of the riser) from sturdy, long lasting refractory brick. The bench can be built from a lot of different materials, including on site sourced earth and clay,weaving together the home with the surrounding. The design of the bench is very varied, matching the style of the house whose integral part and warm center of coziness it will become.
Batch Box Rocket Mass Heater
The Batch Box Rocket Mass Heater design, in short BBR, goes back to Peter van den Berg. The main advantage of the design is a larger, more conventional and horizontal wood feed. That means a lot of wood can be loaded at a time, a batch, thus producing more heat with less frequent refueling. Another upside is that a window can be integrated in the front door. But custom metal work, high performance insulation and a more complex geometry raise the cost of a BBR compared to a J-tube rocket.
The heat transfer can also be realized with a bench. But more often BBRs are integrated into a larger brick bell, where the exhaust gases stratify and give off the heat to the room, similar in aspect to a masonry heater.
Cottage Rocket
RMH can also provide heat for small spaces, like tiny houses, small apartments or a sauna. The Cottage Rocket design is based on the work of Chris McClellan. A Cottage Rocket fits a small J-Tube rocket inside an oil barrel. This very smart and innovative design allows for a RMH even in very small spaces. Depending on the use, more or less mass is also introduced into the barrel. The more mass the less direct the heat, which is important in a tiny house for example. For a sauna model almost no mass would be added, freeing all the heat to the room as quickly as possible.
Pizza/Bread Rocket
Rocket technology can also be used to provide the heat to an oven. Combining the beauty of traditional cob ovens with the efficiency of a rocket lets you enjoy a wood fired oven at a tiny fraction of the firewood usually needed.
The first rocket I ever built powers an outdoor oven for baking in summer. The flavour of food that comes out of a wood fired oven is unique and the whole process very satisfying.
The size and design of the oven will be fit to your oven needs. A small, outside oven for the occasional pizza party? Or an oven big enough to bake 10 loaves of bread every week?