We can suffer quite a few discomforts from dry air: cracked lips, dry itchy skin, bloody noses, irritated vocal cords, etc. But dry air can trigger more serious conditions such as asthma attacks, respiratory infections, and allergic reactions.
According to the website Allergy Be Gone, humidity levels below 35% can have negative effects on your health. Insufficient moisture in the air makes the mucous membranes inside your nose and throat - your body's first barrier against airborne infections - dry and more susceptible to diseases like cold and flu. Dry air is also dangerous for allergy and asthma sufferers, since it can aggravate their symptoms. (1)
So, what is an ideal humidity level? My internet research revealed a lack of consensus. For example, the Mayo Clinic says "humidity in your home should be between 30 and 50 percent". Comparatively, the National Institutes of Health says that "the majority of adverse health effects caused by relative humidity would be minimized by maintaining indoor levels between 40 and 60%". I agree with the NIH. My personal experience is that even 35% is too low. At 35% I still experience static electricity, and so do my poor kitties!
Humidifiers can make a big difference in your comfort and health in the winter. There are different types of humidifiers on the market. The NIH recommends evaporative or steam humidifiers, as cool mist humidifiers can disseminate aerosols contaminated with allergens. (2)
Humidifiers require maintenance; dirty humidifiers can breed mold or bacteria that can make you sick.
Here are two links (to the Mayo Clinic) for some good basic information on humidifiers: types of humidifiers and humidifier maintenance.
Hygrometers are devices that look like thermometers and measure the amount of moisture in the air. They can be purchased in hardware and home improvement stores for about $20. Some humidifiers have a built in hygrometer (called a humidistat).
Low humidity and your home
The following effects of low humidity is derived from allergybegone (1):
- Hardwood floors, wooden furniture and expensive musical instruments can develop cracks and wood flooring can separate at the seams.
- Static electricity can damage computers and other electronic equipment.
- Houseplants suffer from dryness caused by low humidity.
- Wallpaper may peel at the edges
- Low humidity can make you feel as if the air temperature is lower than it actually is. Maintaining a proper humidity level can even save you a bit on heating bills!