HVAC - Ventilation

Building ventilation

The process of bringing outside air into a building, circulating it, and later purging it to the environment is known as Building ventilation. The purpose behind ventilation is to provide adequate indoor air quality by diluting and removing contaminants from the indoor air. This can be achieved either by natural or mechanical means, or by a combination of both.

Natural ventilation

Natural ventilation is done by using air pressure differences existing between the inside of a building relative to the outside of it, across the building envelope. Natural forces such as wind and temperature create these air pressure differences. In naturally ventilated buildings air moves through windows, doors, vents and other openings built-in into the building design and via infiltration/exfiltration.

Mechanical ventilation

Mechanical ventilation is done by utilizing mechanical air handling systems which are commonly referred to as heating, ventilation, and air conditioning i.e. HVAC systems. Mechanical ventilation is more controllable and responsive as compared to natural ventilation in providing adequate indoor air quality hence employed in mainly commercial buildings. An HVAC system provides adequate indoor air quality by:

• Conditioning the air in the occupied space of a building

• Diluting and removing contaminants from indoor air through ventilation

• Providing proper building pressurization.