You can measure the humidity level in your house with a hygrometer, an inexpensive device that can be purchased at discount stores and hardware stores. Humidity is the amount of water vapour in the air, and keeping indoor humidity between certain levels is beneficial for your home.
Normal House Humidity
Normal house humidity is between 30 and 50 per cent. Lower and higher levels can cause various problems.
Humidity tends to fall below 30 per cent in very dry climates, and in houses where a furnace or wood stove runs a lot during the winter. A portable or whole-house humidifier keeps humidity in the normal range.
Low Humidity Problems
Houses that are too dry can cause people to have dry throats and noses, resulting in respiratory problems. Low humidity also causes dry skin. Wood can shrink, resulting in loose furniture joints. Additionally, you'll notice static electricity in clothing and carpeting giving you small shocks.
Humidity rises over 50 per cent in humid climates, especially during warm temperatures. Central air conditioning is the best solution, but room air conditioners and dehumidifiers also can help.
High Humidity Problems
High levels of humidity in a house can result in mould and mildew, problems with dust mites causing allergic reactions, infestation by other bugs, flaking paint and peeling wallpaper.