Four fire engines and around 25 firefighters were called to a fire at a shop with flats above on North Hyde Lane in Southall.
Half of the extraction system from the ground floor to the second floor of the building was damaged by fire. Ten people left the building before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 1749 and the fire was under control by 1906. Fire crews from Hayes, Heston, Feltham and Southall fire stations attended the scene.
The fire is believed to have been accidental, but the exact cause is still under investigation.