Aprilaire Automatic Digital Modulating Control Package for Model 801

The Aprilaire 63 Automatic Digital Modulating Control Package provides precise, responsive humidity control when paired with the Aprilaire 801 Steam Humidifier. This all-in-one control kit includes a digital wall-mounted humidistat, outdoor temperature sensor, duct humidity sensor, and blower activation relay. Together, they allow accurate monitoring, proportional output control, and automatic adjustments to maintain consistent indoor humidity levels throughout the home.

Advanced Digital Wall-Mounted Control

The wall-mounted humidistat features a microcomputer-based design with a large backlit digital LCD screen. It includes both humidification and dehumidification indicators and offers adjustable settings from 0–100% relative humidity. Users can choose between Celsius and Fahrenheit for display flexibility.

Key capabilities include:

• On/off or proportional output signals for precise humidification and dehumidification control

• 0–10Vdc or 2–10Vdc modulating output to provide proportional control to the humidifier

• Remote duct sensing compatibility for improved application flexibility

• Programmable proportional band to adjust sensitivity of control responses

• Outdoor temperature–based humidity reset to reduce condensation risks in colder climates

• 24Vac on/off signal with dry contact supporting up to 1 amp

• Proportional high-limit override to prevent excess humidity in ductwork

• Multi-level lockable menus to prevent accidental changes

Additional System Features

The complete control package includes components that enhance accuracy, safety, and overall system performance:

• Outdoor Temperature Sensor: Automatically adjusts the humidity set point based on the difference between indoor and outdoor temperatures to help prevent window condensation.

• Proportional Duct Humidity Sensor: Measures humidity directly in the duct for primary control or high-limit override protection, reducing the risk of duct condensation and moisture damage.

• Blower Activation Relay: Allows the humidistat to activate the HVAC blower during a humidity call, even when the heating or cooling system is not running, ensuring consistent steam distribution.