There have been a number of rocket stoves featured on various social media websites including different configurations using concrete blocks. One particular configuration used only four blocks that made it a very simple and inexpensive project so I decided to assemble one for myself.
This project called for three standard two-hole blocks and one mid-hole block with the single hole in the middle with open holes on each end. I went to a local hardware superstore and was surprised that they did not have the mid-hole block that I sought so I decided to buy four blocks and I would remove the outer end of one of the blocks in order to make it work. The total cost of the material was $7.03.