Is there a good way to add whole-house humidification in winter?

Asked by Diane
Palmyra, PA

We currently use a room-size humidifier, which is a pain, but we can turn the thermostat down several degrees. and feel noticeably warmer/more comfortable. We have: hot water baseboard heat/oil boiler; central air (so already have ductwork); split-level with fairly open floor plan (probably the only reason the room-size humidifier works ok).


Stillman Jordan

Answered by Stillman Jordan

Stratford, CT


October 10, 2013

Hi Diane,

Humidification is often a concern for homes in the winter time.

As you alluded in your question, there are lots of ways to humidify your home. The easiest way is to do what you are doing now which is have a room by room humidifier.

If you are not happy with this solution, there are humidifiers that are designed to work with most central air conditioning units. My personal favorite is the Nortec RH humidifier because it operates pretty efficiently and has the controls you need to protect your existing central AC system.

The way these humidifiers typically work is there is a steam generation unit that has a steam hose that connects to a steam nozzle inside of the ductwork of your existing central air system. This system then relies on the fan in your central AC system to blow the steam humidified air throughout the entire house.

I have to warn you that whole house humidification systems can cause problems if they are not installed and operated correctly. Here is a list of things that you should make sure that your mechanical contractor does to protect your central AC system:

  • Modify the controls on the central AC unit so it will operate the fan when there is a call for humidification in your house. Remember that most central humidification systems need a separate fan to blow the humidified air around the house.
  • Install a high humidity limit sensor in the ductwork downstream of the steam diffuser. This sensor will shut the humidifier off if the humidity in the ductwork gets too high. This will prevent water from building up inside of your ductwork and wreaking havoc on your ductwork system.
  • Install a fan proving switch in the ductwork system. This will ensure that the humidifier will only run when the fan is operating. This also will help prevent water from building up inside of your ductwork.
  • Be sure that the placement of the steam diffuser in the ductwork complies with the manufacturer's recommendations. The steam nozzles often require that the ductwork go straight for a certain length so the steam has an opportunity to fully absorb into the air before it changes direction. If your ductwork has an elbow right after the steam nozzle then momentum could cause the water particles to hit the walls of your ductwork.

All of this being said, whole house humidification is effective and very convenient when it is installed and operated correctly. Hopefully this helps you to make your home more comfortable!


For more information:

Read "How can I humidify my home naturally?" a Q&A answered by Michael Holcomb.

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