A displacement ventilation, low noise level, mixed air, HVAC system for ventilating a commercial or educational facility. The system includes a central HVAC air handling unit containing first and second duct works for receiving and transmitting conditioned air to rooms of the facility. Additionally, the system includes at least one air displacement terminal housing for delivering conditioned air to the room, where the air is delivered through an outlet in proximity to the floor of the room in a displacement manner.