In less than two minutes, you can learn how to build a rocket stove using only cement blocks. Just watch this brief video, "The 6-Block Rocket Stove," for the easy instructions.
The video's clever design for a dual-burner DIY rocket stove uses only six concrete masonry units (CMU), also known as cement blocks or foundation blocks. By stacking the blocks as demonstrated, you'll be able to channel enough heat from a small fire to cook food in two separate pots.
If you've not familiar with the concept of rocket stoves, these efficient cooking (and heating) devices are typically compact and simply designed. A rocket stove generates heat with substantially less environmental impact than an open fire, burning up about half the flammable material. Fires can be built and maintained inside rocket stoves using small twigs, branches and even grasses — making the devices especially suited to places where wood is scarce. This type of stove is valuable in off-the-grid living and rural applications where gas or electricity isn't available. Rocket stoves can be used to cook food or heat small spaces; some rocket stove plans incorporate heat exchangers for heating large quantities of water.
To build the rocket stove featured in this video, you'll need 3 standard cement blocks, 2 half-blocks and one stretcher unit. As the video demonstrates, the blocks can be arranged quickly, and your rocket stove will be fully operational in a matter of minutes. Start by placing one standard block lengthwise, with its solid surface down, and topping it with the stretcher unit having its openings facing skyward. Flank this arrangement on each end with one standard block, openings turned out to the sides (the side-facing openings will function as fuel magazines into which you'll feed the flames). Place the half-blocks on top to create two vertical chimneys, over which you can place recycled burner grates to support cooking pots and to allow for a draught. And that's it: Now you know how to build a rocket stove for cooking.
The video also includes instructions to build a more compact, single-burner rocket stove using just four cement blocks.
Rebecca Martin is an Associate Editor at MOTHER EARTH NEWS magazine, where her beats include DIY and Green Transportation. She's an avid cyclist and has never met a vegetable she didn't like. You can find her on Google+.