In heating-dominated winter conditions, what is a common issue if humidification is not provided?

• A. Indoor relative humidity can be unacceptably low.
• B. Indoor relative humidity can be too high.
• C. There will be condensation on windows.
• D. The system will overcool rooms.

Answer: (B)

In winter’s heating-dominated conditions, indoor air tends to become very dry if you don’t add moisture. Heating outdoor air lowers its relative humidity, and without humidification the indoor relative humidity can drift into uncomfortable, unacceptably low levels. That dryness shows up as dry skin and eyes, throat irritation, and more static electricity, and it can actually make the air feel cooler than it really is, prompting people to feel chilly even at the same temperature. Condensation on windows would require higher humidity, not the low humidity you get without humidification, and overcooling isn’t a direct result of missing humidification because it’s about the temperature control, not the moisture content. So the common issue is that indoor humidity becomes too low.