This rocket stove is for a greenhouse. Rocket stove will burn outside air. Burning inside air and exhausting it causes cold outside air to come in to replace the exhausted air. Lighting: small pile of DRY wood varying in size from minute twigs to 1/2 inch splinters (kindling). Fill bottom of the fire box with crumpled paper/cardboard. Light, blow hard toward the J tube. After flames steadily head that direction, drop mixed size kindling in. The draft is better with cold air.