The Aprilaire Ventilation Control System eliminates uncontrolled ventilation and ensures the correct amount of ventilation for the needs of the home, states the manufacturer. The system consists of a 6-inch damper, controller, and transformer. The system has time-based control with outdoor temperature and indoor relative humidity operating limits. The control opens a damper with a fan or equipment call to meet a desired ventilation requirement that is set by the installer with a knob (0 to 60 minutes) and cycle timing (1, 2, 3, or 4 hours). Once the ventilation need is met, the controller closes.
Aprilaire, P.O. Box 1467, Madison, WI 53701-1467; 608-257-8801; www.aprilairecontractor.com.