The Aldes CER3-S Constant Exhaust Register incorporates a pressure independent balancing damper that automatically regulates airflow in duct systems to constant levels. The passive control element in the CER3-S requires no electric or pneumatic power or sensors, and works solely off system pressure.

The CER3-S compensates for changes in duct pressure caused by stack effect, operable windows and doors, wind, loading filters, etc. The CER3-S provides a low-cost solution to maintaining the correct airflow balance of ventilation systems, improving system performance and indoor air quality, which can provide significant savings on annual operating costs.