Ventilation

Ventilation is used to remove unpleasant smells , excessive moisture , introduce fresh air to the building interior to prevent stagnation. This can be achieved by the use of mechanical equipment and ducting .
Fans

(a) Vortices
(b) Expelair
(c) Breezax
(d) Angram
(e) Elicent
(f) Wood
(g) Whirlly Birds