100mm BatchRocket Mass Heater

Our smallest but still powerful heater. We found that for old portuguese houses this heater would often be sufficient to comfortbly heat a space. It gives you more control than one of our larger models because it heats up more quickly and cools down more quickly, and sometimes that is what you want. Portuguese winters can be cold, especially in the evening but then in the day when the sun comes out, temperatures rise and room temperatures become comfortable to a point where heating is not needed anymore. Find out below if this heater is big enough for your space.

100 mm BatchRocket mass Heater 

Our project started with this design. Developing it was our attempt to bring rocket stove technology to the people. Our main goal was to make it as cheap as possible by standardizing the design and fabrication process and looking for the best and cheapest materials. 


The 100mm BatchRocket mass heater has a dimension of 58x58x130 cm. It weighs about 600 KG.  It uses about 3 KG’s of wood per batch which gives off enough heat for 2 to 6 hours depending on the space you are heating.

The materials used are: 

  • Firebricks
  • Sand and clay to form firecob (which is cob without straw)
  • HTC (High Temperature Cement) for gluing the firebricks to create the core of the heater
  • Firecord and ceramic fibre blanket for insulation
  • A few steel parts: the door, the secondary air channel and the top plate


Whether this BatchRocket Heater is powerful enough to heat your space depends on many factors, but it is found that taking only the following aspects into account is often sufficient in determining the needed heater, and whether this one is sufficiently powerful:

  • How big the space is in cubic meters (m3)
  • How warm you would like it to be in the space compared to the outside temperature
  • How well is the place insulated.

If you provide these details to us we can calculate whether the stove is suitable for your space.

Purchase includes:

  • All the materials
  • Us building the heater in your place in two days time
  • User manuals on
    • drying the heater
    • maintenance of your heater
    • daily use of your heater
  • Free support while you become accustomed with your stove  

    Does not include:

    • Flue pipe installation
    • Any preparation work that needs doing before we can start installation
    • Applying any form of finish, such as plastering
    • Transportation fees

    100mm BatchRocket mass heater

    Get In Touch

    Send us a message with the properties of your space and your personal requirements and we can advise you on what size Heater is most suitable for the space you want to heat. Also any questions are welcome.

    Reach out to us

    Share your ideas, ask your questions. We are here to help.


    Rua Principal 563
    3305-033 Benfeita

    Call Us

    (+351) 967 651 904
    for calls or WhatsApp


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    Our designs derive from the Batch Box Rocket concept by Peter van den Berg.
    Everything is published under the Creative Commons Attribution-ShareAlike 4.0 International license.

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