The dual duct variable air volume (VAV) system is a type of air conditioning system that uses two air streams to regulate the temperature of a space. It is commonly used in commercial buildings and is known for its energy efficiency. The dual duct VAV system works by having two separate air streams, one for cooling and one for heating. The two streams are mixed in a mixing box and then sent to the space. The temperature of the space is then regulated by the amount of air sent from each stream. The system is designed to reduce energy consumption by only providing the amount of air needed to maintain the desired temperature. The dual duct VAV system is also beneficial in that it allows for greater control over the air flow, allowing for better air quality and temperature control. Additionally, the dual duct VAV system is often more cost effective than other types of air conditioning systems.