“In the aftermath of a disaster, purifying drinking water may be a priority. The quickest, safest method could be boiling. This biomass stove only requires four concrete blocks, a tin can with both ends cut out and a gas stove eyelet top. The completed stove is sturdy enough to hold a several-gallon container of water, stew or a heavy cast iron Dutch oven.”
As numerous readers point out in the YouTube comments, cinder blocks are not the most durable option for rocket stoves. The blocks will crack eventually. Here, this gentleman is demonstrating how to boil water in an emergency situation such as a tornado. Clay chimney blocks or firebrick would be more durable options if you plan on cooking on the stove long term.
It’s very interesting to see so many variations of this basic rocket stove concept. Useful adaptations include raising the stove to a comfortable cooking height, adding a squashed can or screen to improve air flow under the sticks, adding a brick in front to better support the sticks, and using a grill grate on top that allows the pot or skillet to sit closer to the stove and conserve heat. There are lots of other useful tips such as facing the front of the stove towards the wind to improve air flow and using Vaseline coated cotton balls or other fire starters to start the fire more easily.
YouTube
There are lots of similar stoves on YouTube. Here are four different versions that look practical. I like the fact that they can be assembled in minutes with no special skills. There are hundreds of similar videos on YouTube if you want to get even more ideas.
DIY Rocket Stove – Simple Homemade Rocket Stove
How I built my rocket stove, grill, oven all in one
How to build a better brick rocket stove for $10
Brick Box Rocket Stove using firebrick
A primary design principle of a rocket stove is to use low mass to increase heat transfer and reduce fuel use and emissions. Cinder blocks, masonry rock stoves, and Dakota trenches are energy thieves, meaning the high mass is stealing energy into the pot. A well designed rocket stove utilizes low mass insulation and may include even secondary combustion, heat shields, cast iron tops and other design improvements for boiling large pots of water with minimal fuel that a DIY cinder block rocket stove is incapable of performing.
There are lots of other stove designs, such as TLUD stoves too, that have more advanced combustion principles that can perform these tasks without having to monitor and feed the stove continuously as well.
Regards, SilverFire Stoves (www.silverfire.us)
Yes, this is true. We’ve covered many other rocket stoves in previous blog posts. The link in my previous comment explains many of these things in detail. The cinder block/brick design is primarily for emergencies. It’s low cost and simplicity helps encourage people to jump in and start experimenting. All too often people read about this stuff but never do anything.
Watch this video if you want to learn how to build a more efficient stove:
Principles of Rocket Stove Design Simplified https://www.youtube.com/watch?v=92mrPwNhjYQ
This stove is so easy to do I might make one just for fun with some leftover firebricks. Some people in hot climates cook with these stoves to keep heat out of the house. They’re perfect for backyard get-togethers, backyard camping and canning garden produce. I saw a video of a lady who cooks this way all the time to save money and keep cooking messes outside. She gradually feeds really long branches into the stove so she doesn’t have to cut the wood. Rocket stoves work great with thin branches so you don’t have to buy firewood.