Double wall wood stove pipe is used when there is less clearance from the back of the wood stove to the wall or to the ceiling. It allows wood stoves to be installed in smaller rooms without taking up as much floor space.
A single wall stove pipe must have 18 inches of clearance from any wall or ceiling. The double walled variety needs 8 inches from the ceiling and 6 inches from a wall. The clearance requirements are usually stamped on the pipe itself. After these are met, the pipe still needs connected to a class A chimney pipe for venting to the outside.
Another advantage of double wall stove pipes is that they come in longer sections. Since most wood stoves vent from the top, this allows for a longer stretch of pipe before it is angled towards the wall for venting. This is particularly beneficial for wood stoves installed in homes with high ceilings, such as split level or loft designs.
It is not only more visually appealing in these architectural styles, as the longer pipe radiates more heat into the home. At the same time, the layer of insulation, usually air, or in some cases, a ceramic inlay, keeps the pipe from being too hot to the touch.