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Mechanical / HVACaka: VAVaka: VAV systemaka: VAV box

Variable Air Volume

In Plain English

An HVAC system that saves energy by delivering more or less air to each zone depending on how much heating or cooling is needed.

Definition

An HVAC distribution system that varies the volume of conditioned air delivered to each zone based on the zone's current heating or cooling load, while maintaining a constant supply air temperature. VAV boxes modulate their damper position in response to the zone thermostat, reducing airflow when the load decreases. VAV systems are more energy-efficient than constant-volume systems because they reduce fan energy at part load.

Example

The 200-zone VAV system reduces supply fan speed from 100 percent to 40 percent during overnight periods, saving over $40,000 per year in energy costs.

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