Vertical Discharge Air Exhausters are ideal for "spot" ventilation of specific problem areas where rapid air removal is neccesary or for general plant ventilation. Hi-Ex Axial Fans are commonly used for general ventilation, however, when equipped with Heat and Smoke option this series of fans incorporates features exclusively designed to exhaust heat and smoke in the event of fire. Hi-Ex ventilators are available in three standard drive arrangements models HC, HF, and HX.