The unique design of the Solo Stove is what enables it to burn so hot and so cleanly, without the smoke and smell of a regular campfire.
Vent holes at the bottom of the stove suck air in. As the air enters the vents, it does two things.
First, it delivers oxygen to the base of the fire helping it to grow and spread. Secondly, it travels up, between the double walls of the stove, increasing in temperature as it goes. By the time it exits the vent holes at the top of the stove, it is super-heated.
This super heated air feeds the top side of the fire, helping it to combust more completely and efficiently, thereby eliminating most of the smoke and turning it into heat instead.