Answer:

flues

Answer	Crossword Clue
FLUES	Where there's smoke
FLUES	Smoky places
FLUES	They're often full of hot air

FLUES	Chimney channels
FLUES	Sooty sites
FLUES	Soot collectors
FLUES	Chimney parts
FLUES	Passageways for Santa
FLUES	Smoke pipes.
FLUES	Passages for air, gases, etc.
FLUES	Shafts.

FLUES	Chimneys.
FLUES	Ducts.
FLUES	Vents.
FLUES	Smoke carriers
FLUES	Chimney passages
FLUES	Windways
FLUES	They may be full of hot air
FLUES	Draft raisers

FLUES	Smoky passages
FLUES	Chimney pipes
FLUES	Fireplace smoke escapes through them