Bottom vent holes allow oxygen to the feed the fire from below while simultaneously channeling warm oxygen up between the walls of the stove and back into the fire. A MORE EFFICIENT BURN: A more complete chiminea for garden burn means the little particles that would have been smoke are burned up by the top vents. It also means no more half burned logs to deal with. NO MORE SHUFFLING FROM SMOKE: Since the Bonfire burns with almost no smoke, you'll spend less time dodging smoke and your clothes won't smell like outdoor heater. You'll have more backyard or camping memories around the spectacular Solo Stove portable fire pit.