The Kon-Tiki was developed by Hans-Peter Schmidt in Switzerland with the Ithaka Institute> based on the MOKI Cone Kiln from Japan.
There is a nice description in the video of air currents around the cone kilns. The Ton Tiki and The Tasmanian version developed by Frank Strie called the Kon-Tiki-Tas. Are both large - vinyard scale cone kilns.
Information about smaller kilns and backyard scale variations can be found at: http://backyardbiochar.net/