AprilAire Model 400 Water Saver Evaporative Humidifier

Whole-House Humidifier



AprilAire Model 400 Water Saver Evaporative Humidifier uses 100% of the water that goes into the system by capturing excess water in a reservoir. Water is heated into a vapor and dispersed throughout the home before more water is added, helping save money on water and utility costs. 


Balanced Humidity Improves Your Body's Natural Defenses

Model 400 with Automatic Digital Humidifier Control Features:





HUMIDITY FOR HEALTH AprilAire Humidifiers can help you maintain optimal humidity in your home 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.



HUMIDITY FOR COMFORT Balance your humidity to preserve your home and protect its occupants from dry air issues like static shock and chapped skin. 



BUY WITH CONFIDENCE This humidifier was designed and manufactured in the U.S.A. by AprilAire—the inventor of the whole-house evaporative humidifier, and the leader in Indoor Air Quality since 1954. 









ONBOARD SENSOR Automatically turns on the HVAC fan to measure the relative humidity inside the ductwork and from all parts of the home. Turns on the humidifier whenever the measured humidity drops below the set point.



WHOLE-HOUSE HUMIDIFICATION For Homes With Ducted Heating and Cooling Systems. 



FULL COVERAGE For tightly constructed homes up to 5,000 square feet, with a capacity of 17 gallons per day.







Humidity Plays a Key Role in Wellness

Benefit Icon   Health

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.

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Benefit Icon   Comfort

Whether your home is in a dry region of the country, or in an area with seasonal dryness, maintaining the right level of humidity can make all the difference in how comfortable you feel in your home.

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Benefit Icon   Preservation

Help preserve the natural beauty of wood floors, cabinetry, furnishings, and anything else in your home susceptible to warping, cracking, or other permanent damage due to dry air.

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Healthy Humidity Icon

Breathe Healthy Air, no matter when or where with the AprilAire Healthy Air Systemâ„¢. Find out how balancing your humidity benefits your health.

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Installation instructions

Saddle valve

Automatic Digital Humidifier Control

Outdoor Temperature Sensor

24V Transformer

#45 Water Panel



*Model 400M available with manual humidistat. Product features will differ.







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Healthy Air Professionals Who Care

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