The system is designed to maintain the desired purity, temperature and over-pressure in the department. The supply air quantities are estimated based on heat load, air leakages and amb. Air quality. Ventilation systems can be with or without air washer. The exhaust system can be either mechanical or through gravity release dampers.

Beside axial flow and centrifugal ventilation fans, Draft-Air offers special purpose centrifugal fans for high temperature, fume/vapour exhaust, dust handling, material, conveying, induced draft and forced draft applications.