ICC Commercial Mechanical Practice Exam

A Variable Air Volume (VAV) system is primarily designed to vary the amount of air supplied to different zones within a building to maintain the desired temperature. This functionality allows it to efficiently respond to the varying thermal loads in different areas, ensuring that occupants remain comfortable without overcooling or overheating specific spaces. By adjusting the volume of air, the VAV system can optimize energy use while ensuring adequate heating or cooling.

In commercial buildings, where different rooms may have different occupancy levels or heat-generating equipment, the ability to modulate airflow becomes essential. The VAV system accomplishes this by using dampers that adjust the volume of air delivered based on the temperature set points and the current conditions in each zone. This zoned approach to airflow is more energy-efficient compared to systems that provide a constant airflow throughout the building.

The other options do not capture the primary function of a VAV system. While maintaining constant ventilation rates, providing exhaust air, and filtering air are important aspects of HVAC systems, they do not specifically represent the unique capability of VAV systems to vary air volume for temperature control in different building zones.