The mixing box section is equipped with opposed action dampers of various sizes for the fresh air, return air and exhaust air, that can be linked together or operate independently.

The damper system permits the use of 100% fresh air with 100% exhaust air or, any other percentage combination of fresh / exhaust air.

Dampers are opposed action, activated by means of special tooth-gear, made of glass-reinforced nylon, having high mechanical strength and limitless life duration. Blade bearings are of the same material and no lubrication is required.

Operation is simple, smooth and precise, permitting linear regulation.