Workers have to clean them and I am not sure there is any evidence to show that such areas actually prevent smoke escaping.

The smoke escaped through a hole above it, near the center pole.

Very little smoke escapes from this unit while in operation.

The smoke would escape through a hole in the roof that was about half a foot wide.

After a long moment of silence, he let the smoke escape his parted lips.

The smoke from the fire escaped through a hole in the top of the tipi.

Moisture and smoke escaped from small vents in the top for six to eight days.

Any sign of smoke escaping can be considered a possible site for sewer gas to escape.

The settlers then directed their steps towards the place from which the smoke escaped.

A fire burned constantly to combat the cold mountain air, and smoke escaped through an open window.