The aims of smoke ventilators are:
- To extract smoke and gas in order to make emergency exits accessible for the evacuation of people
- To maintain visibility in the building to facilitate the work of the emergency services
- To prevent flashover (combustion of all gas in the building).

There are a number of devices which combine smoke and heat extraction with roof access, but these access ways are designed for people who need to move about on the roofs (to maintain vents, for example).