An HVAC system has two variable-air-volume (VAV) systems, a first VAV
system for moving fresh air and a second VAV system for moving recycled
air. Both the fresh air and recycled air are cooled and dehumidified by a
single heat-exchanging coil. The fresh and recycled air streams travel
independently in separate ducts until the air streams reach a remotely
located mixing box where the air streams mix and ventilate into a room or
zone of a building. The HVAC system uses carbon dioxide and temperature
sensors in order to regulate the flow of fresh and recycled air to
various mixing boxes throughout the building.