Not only is Fargo cold for six months of the year but once inside the air is dry. I can feel my skin dry up and start to itch. We make sure our humidifiers are working. They’re almost as important as our furnace. But my shins aren’t the only reason to humidify the air. Machines work better, wood doesn’t shrink or crack, and optimal humidity will even keep the doctor away. Gary L. Berlin in the February issue of Engineered Systems, writes on the topic in his article, “Restoring The Low Limit For Indoor Relative Humidity.”
Berlin describes the research history into humidity and health. He covers the what the industry has done to through its ASHRAE established standards to keep humidity at recommended level. And how more work needs to be done to keep indoor relative humidity from falling too low.
See this Sterling Humidity Chart. A decrease in bar width indicates decrease in effect.
Source: ASHRAE, adapted from Sterling et al., 1985. Lennox.com
Sterling Chart (Optimum relative humidity range to minimize harmful contaminants)
In the early 1980s, Elia Sterling of the University of Vancouver did an extensive study of previously published research concerning indoor relative humidity and its effect on the occupants of an indoor space. This study established that both high and low relative humidity levels had a deleterious and costly effect on the health and productivity of the occupants of a facility as related to bacteria, viruses, fungi, dust mites, respiratory infections, allergies, asthma, and ozone in the workplace, schools, and home.