Although a pellet stove does not need a traditional chimney, it does require an exhaust pipe to the exterior of the building. This keeps potentially toxic gases from building up inside.
Pellet stoves burn compressed pellets that contain wood shavings and sawdust. The pellets burn hotter than wood burns in a traditional wood stove and produce less ash, creosote and smoke with fewer pollutants than wood-fire smoke. A fan blows the pellet stove’s exhaust smoke out of the unit through a narrow pipe. Many users vent the pipe through an existing chimney, but this is not essential. It is possible to vent the pipe directly outside at a slight vertical angle.