What is the purpose of a VAV system in HVAC?

A Variable Air Volume (VAV) system in HVAC is designed specifically to enhance energy efficiency and comfort by regulating airflow and temperature across different zones within a building. The primary function of this system is to shift the volume of air supplied to a space based on the heating or cooling requirements of that particular area.

In a VAV system, airflow is varied to meet the changing demands of the space, which is particularly beneficial in buildings where occupancy and thermal loads fluctuate throughout the day. By decreasing or increasing the flow of conditioned air, a VAV system can maintain a consistent temperature while minimizing energy consumption. This flexibility allows for precise control, leading to improved occupant comfort and reduced operational costs.

For instance, in a conference room that is frequently occupied, the VAV system might increase airflow to cool or heat the room quickly when occupants enter. Conversely, in areas that are less frequently used, the system can decrease airflow, thus saving energy.

The other options do not capture the main purpose of a VAV system. While filtering air pollutants, maintaining constant air pressure, and providing emergency ventilation are important functions in HVAC systems, they do not specifically pertain to the primary operation and benefits of a VAV system.