What does a variable air volume system do?

A variable air volume (VAV) system is designed to adjust the volume of conditioned air delivered to different spaces based on the individual heating and cooling requirements of those spaces. This system operates by varying the flow of air in response to changes in the temperature demands of occupied areas.

When the temperature in a particular space rises above or falls below the set point, the VAV system modulates the amount of air supplied to that space to maintain comfort. By doing so, it efficiently manages energy use while ensuring that the spaces are adequately heated or cooled. This ability to respond to varying conditions is what distinguishes a VAV system from other types, such as constant air volume systems, which maintain a steady flow of air regardless of temperature changes.

The other choices do not align with the primary function of a VAV system. For example, increasing air pressure or maintaining a constant volume does not accurately reflect the system's purpose. Likewise, reducing air quality is counterproductive to the intended goal of any HVAC system and particularly misrepresents the function of a VAV system, which aims to improve indoor air quality by adequately conditioning the air supplied to a space.