Ventilation - requirement, function and system

From the view point of working conditions & comfortable living, the good and efficient ventilation system should meet the following functional requirements.

Strategies for ventilation

The first strategy for ventilation is to eliminate the pollutant source. Because the source control is the most effective and preferred method of providing good indoor quality for people in most cases.

And this is usually done via ventilation, i.e. usually increasing ventilation rates.

Rate of supply of fresh air

The quantity of fresh air to be supplied to a room depending on the use of a building.

The rate of supplying fresh air is decided by considering several factors such as a number of occupants, type of work, period of working, the age of occupants, etc.

Air movement (or air changes)

Air has to be moved or changed to cause proper ventilation of the space.

The rate of air change depends on the number of persons inside, room temperature, nature of the work, different room categories, and activities, etc.

Temperature of air

It is desirable that the incoming air for ventilation should be cool in summer and be warm in winter - before it enters the room.

Also the velocity of air is very important, including ventilation strategy, distribution pattern, etc.


The air contains certain amount of humidity.

Air quality

It plays a significant role in the comfort of people affected by a ventilation system.