Following our friend’s advice from Canada, we have decided to give it a try to this new stove. Rok is currently writing his thesis on this subject. In the General Hospital in Bukavu, the team decided to build one of these stoves as a sample.

Our first burning attempt was promising, although we need a much longer fuel briquette (at least 3 times longer than its normal size) to make it burn properly. Because our briquette is used in a different stove (our own metal bucket version), it kept falling down. We are now pressing some jumbo briquettes to specifically test it with this model of stove. The only problem is it will take many days to get the fuel briquette completely dry.

As Rok explained to me on his e-mail:

“I’ve just started with briquettes here in Vancouver, paper & sawdust, so i can do some simple testing. I’ll be heading down to Aprovecho and Richard to do more extensive testing, soon I hope.

The key benefit with this process of vertical position of the briquette is the draft generated that provides a great burning. Cos the briquette is in vertical position, the draft changes from vertical to horizontal, so the stove does not need to be so high. And yes, you feed the new briquette just with pushing the previous one inside, so they get burned just from the inside.

To explain it from a different view, the most efficient stoves are the ones with fast draft, but as little air coming in as possible. Its contradictory to some extent but manageable with this ‘knee’ type of the rocket stove. Philips stove works like magic using this principle with additional electric fan, but its more than $100 to produce..

I’d like the principle to be applied to metal or clay stoves, but clay would be easier as you can make the dimensions as desired. Are there any local brick-makers where you’ve been? Clay insulators are so much more efficient and you need to burn them to get the lightness and durability.”