The types of air distribution systems used in textile mills are mixed air, displacement, and upward displacement systems. The mixed air system involves supplying air at a high momentum and turbulence above the machinery. An air outlet quickly equalizes temperatures, lower the momentum of the supply air, and mixes the supply air with the existing air. The displacement system involves supplying air that displaces the existing air. The upward displacement system involves supplying air at a low momentum at the level of the machiery. Removal of exhaust air is above the machinery. Optimizing the operations of these systems involves achieving correct air conditions for both machinery and personnel. Additionally, the air distribution system should decrease the quantity of pollutants, dust, and fly. 8 refs.