<P> Variable Air Volume (VAV) is a type of heating, ventilating, and / or air - conditioning (HVAC) system . Unlike constant air volume (CAV) systems, which supply a constant airflow at a variable temperature, VAV systems vary the airflow at a constant temperature . The advantages of VAV systems over constant - volume systems include more precise temperature control, reduced compressor wear, lower energy consumption by system fans, less fan noise, and additional passive dehumidification . </P> <P> The simplest VAV system incorporates one supply duct that, when in cooling mode, distributes supply air at a constant temperature of approximately 55 ° F (13 ° C). Because the supply air temperature is constant, the air flow rate must vary to meet the rising and falling heat gains or losses within the thermal zone served . </P>

What is the difference between vav and cav
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