Model 720A is the highest capacity AprilAire evaporative humidifier at 21 gpd and includes an automatic digital control

A cross-axial fan on the Model 720A humidifier pulls heat directly from the furnace. The model 720A is the highest capacity AprilAire evaporative humidifier. Easy to install, it's the best choice for systems with low or variable speed air handlers. The 720A includes an automatic digital control that delivers the correct level of humidity based on indoor and outdoor temperatures.
Features • Highest capacity AprilAire evaporative humidifier • HydroCoreTM Technology recirculates water to maximize panel saturation with a 60% reduction in wastewater* • Reconfigurable fan design allows for increased installation options on vertical or horizontal systems • Fast and easy installation for every application with +/- 3 degree level tolerance • Variable speed fan provides low speed option for reduced noise • One-piece HydroCoreTM Water Panel cartridge simplifies annual maintenance • Best choice for systems with low or variable speed air handlers • Pulls heat directly from the plenum • Designed for tightly constructed homes up to 6,250 ft2 total *Compared to AprilAire 700 Humidifier Principle of Operation The AprilAire 720 Fan-Powered Evaporative Humidifier delivers maximum moisture output with superior water efficiency for ducted HVAC systems. When the humidifier control signals that humidity is low, water and air flow into the HydroCoreTM where natural evaporation occurs. Increased output and water conservation are realized with water recirculation technology. The humidifier fan returns humidified air back to the duct where your HVAC system can distribute humidity throughout the home. The 720 Humidifier utilizes water for both evaporation and the removal of solids left behind during the evaporation process. Installing on softened water is recommended. Water may or may not be noticed in the drain line due to the improved efficiency. Once humidity levels are reached, unused water is sent down the drain to prevent standing water from being retained. It is normal to notice a small surge of water in the drain line for this brief event. This is crucial to help flush away trouble-causing mineral deposits and prolong time between service intervals.