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Skuttle Under Duct Humidifiers are real workhorses that perform well on heat pumps and high-efficiency heating systems. In fact, they are superior to plenum-mount flow-thrus on today’s 90-plus furnaces.

Both the Flow-Thru and Drum Under Duct units handle more air volume than their plenum-mount counterparts because air flows directly through the ductwork rather than through a 6 in. (15.24 cm) bypass tube.

With normal maintenance, they cause no airflow resistance. The humidifiers’ efficient design actually increases airflow around the evaporator pads. The unique mounting frames allow fast, simple removal from the duct for easy cleaning and servicing.

Environmental Facts

Because Model 55UD employs the flow-through principle of humidification, it uses more water than other types of humidifiers. However, Skuttle engineers have reduced water consumption to the minimum necessary for effective humidification. Electrical consumption is minimal—about the same as a 25-watt light bulb.

How it Operates The Skuttle 55-UD Under Duct Humidifier works with your furnace to distribute humidified air throughout your home. It is designed to mimic nature's process of warm air evaporation with the help of a porous evaporator pad. As warm air from your furnace passes over the evaporator pad, water evaporates evenly into the warm air stream. Your heating system then circulates the humidified air throughout your home. Using Skuttle 55-UD regularly can restore your home's humidity to a healthier and more comfortable 30 to 45 percent.

Performance The Skuttle 55-UD Humidifier can humidify homes up to 4,762 square feet, depending on your home's insulation level. Use the guidelines below to determine whether or not this model will work for your home.

  • Tight House - Tight houses have insulated walls and ceilings, vapor barriers, weather stripping on doors and windows, snug doors, snug windows, and a fireplace damper. One-half air change per hour.
  • Average House - Average houses have insulated walls and ceilings, vapor barriers, loose doors, loose windows, and a fireplace damper. One air change per hour.
  • Loose House - Loose houses have no insulation, storm doors, storm windows, weather stripping, or vapor barriers. Two air changes per hour.
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