Section 2(122) in Tamil Nadu Combined Development and Building Rules, 2019
(122)"Ventilation" means supply of outside air into, or the removal of inside air from an enclosed space, which includes -(i)Natural Ventilation - Supply of outside air into a building through window or other openings due to wind outside and convection effects arising from temperature or vapor pressure differences (or both) between inside and outside of the building.(ii)Positive Ventilation - the supply of outside air by means of a mechanical device, such as a fan.(iii)Mechanical Ventilation - Supply of outside air either by positive ventilation or by infiltration by reduction of pressure inside due to exhaust of air, or by a combination of positive ventilation and exhaust of air.
