AprilAire introduced the first evaporative humidifier for forced air furnace systems back in 1954. Since that time, AprilAire continues to lead the industry in whole home humidification systems. Our evaporative humidifiers work by piping water into the distribution tray located at the top of the humidifier. The water is uniformly distributed across the width of the tray and through a scientifically designed system of outlets. It flows by gravity over the Water Panel evaporator. Dry, hot air from the HVAC system is moved through the moisture-laden Water Panel evaporator. Natural evaporation takes place, the water is turned to vapor, and the humidified air is circulated throughout your home. This unit is uniquely designed to evaporate 100% of the water going into the humidifier. It incorporates a special two-stage float system to maintain the optimal amount of water and protect against overflow. In the unlikely event the float system fails, it is recommended an overflow tube (1/2 inch inside diameter) be installed to the base of the humidifier and run to a condensate pump, a sink, or a floor drain. Follow the required maintenance instructions. INCLUDED IN THE BOX: Installation instructions and template, humidifier with built-in bypass damper, 24 VAC transformer, automatic digital humidifier control with sensor, outdoor temperature sensor, saddle valve, solenoid valve, and Model # 45 Water Panel

Features & details

The Model 400A bypass humidifier is a high-capacity, water-conserving humidifier (0.70 gallons evaporated per hour) incorporating a water recirculation system for use where drain facilities are not accessible or available. It uses 100% of the water that goes into the unit. Automatically adjust humidity levels based upon outside air temperature with Automatic Digital Control and remote sensing bulb. Humidifies up to 4,000 square feet if your home is tight in construction. The Model 400A is also a good choice for homes with heat pumps. Due to lower plenum temperatures the unit should be connected to your hot water supply line. This humidifier can be installed on the supply or return air ductwork. It is also left or right side reversible. Includes automatic digital control humidistat, sensing bulb, water pad, 110v to 24v transformer and manufacturer's special instructional DVD.

BUY WITH CONFIDENCE This humidifier was designed and manufactured in the U.S.A. by AprilAire – the inventor of the whole home evaporative humidifier, and the leader in indoor air quality solutions

FULL COVERAGE up to 5,000 square feet in tightly built homes with a capacity of 17 gallons per day

AUTOMATIC HUMIDIFIER with dual sensors to monitor and respond to both outdoor temperature and indoor relative humidity to deliver optimum humidity 24/7 throughout the home – simply set it and forget it

CONSERVES WATER using a unique process that evaporates 100% of the water flowing into the water panel

HUMIDITY FOR HEALTH AprilAire Humidifiers can help you maintain optimal humidity in your home of 40% – 60% which has been shown to reduce the incidence of respiratory infections and symptoms related to allergies and asthma by minimizing the formation of bacteria and viruses, fungi, and dust mites. In addition, you’ll feel more comfortable while also preserving items in your home susceptible to damage from changing humidity or dry conditions.

Automatic Digital Control Features

Shows that the humidifier is operating

Allows you to check relative humidity level

Tells you when it's time to change the water panel

Gives you service alerts

***********items needed for installation*************

Items needed for the installation that are not included: 1/4" copper tubing for water line, 6" round ducting and elbow for bypass air, 2-conductor 18 to 22 gauge wire. These items are available in our