American Aldes patented* Zone Register Terminals (ZRT®) are designed to introduce flexibility and dynamic control of central ventilation systems. Used in both large and small systems, the ZRT-IL controls ventilation without the need for individual fans. Each ZRT-IL is a combination register box, control damper, removable access plate, and optional flow regulator(s). This unique combination provides up to three different control schemes without the need for expensive pneumatic, electronic, or DDC control systems.
The ZRT-IL-1 model provides on-off control for on-demand ventilation. A CAR-II Constant Airflow Regulator in the ZRT-IL-1’s extended duct collar places a maximum flow limit on each terminal.
The ZRT-IL-2 model can be used for combination low-flow indoor air quality ventilation and on-demand high-flow spot ventilation, such as bathroom exhaust fans, using the same central fan system. This is achieved by integrating a CAR-II minimum airflow controller directly into the damper sub-assembly. With the damper completely closed, the factory calibrated CAR-II will still allow steady, low-continuous ventilation during fan operation. When other ZRT-IL terminals are opened for on-demand control of spot ventilation, the closed ZRT-IL-2s will maintain the specified low continuous rate through the CAR-II minimum flow control. By opening the ZRT-IL-2’s control damper, the low-flow regulator is removed from the air stream, allowing either controlled (optional using a second CAR-II) or full maximum-boost ventilation.