An indoor hygrometer, sometimes called an indoor humidity meter, is a device that measures the amount of moisture in the air inside a building. It is used in both residential and commercial spaces to monitor the humidity level for various purposes, for example to ensure a comfortable environment and to make sure that certain kinds of equipment, like air conditioning systems, work effectively. In residential settings, an indoor hygrometer is commonly used to avoid problems caused by too much moisture, such as condensation, mold, and allergies. Too little moisture can lead to other problems, like static electricity, itchy skin, and breathing difficulties. An indoor hygrometer can also be used in specialized storage areas, such as cigar humidors and museums, where items can be damaged by the wrong humidity level.
Depending on its temperature, air can hold different amounts of moisture. The measurement used by an indoor hygrometer is called relative humidity (RH). Relative humidity indicates the percentage of moisture in the air at a specific temperature, compared to the maximum amount of moisture the air could hold at that temperature. A RH percentage of 30-50% is usually recommended for indoor living spaces. If the RH percentage is over 100%, condensation occurs.
An indoor hygrometer can be used to avoid problems caused by too high or too low relative humidity. Too much moisture in indoor air can promote the growth of mold and mildew, causing allergies, and can also lead to other problems like condensation on windows, musty smells, and wet stains on walls and ceilings. A dehumidifier can be used to decrease the relative humidity if an indoor hygrometer indicates that the RH percentage is too high. Air that is too dry can cause chapped, itchy skin, breathing difficulties, problems with electrical equipment, and can also damage wooden furniture. A humidifier can be used to increase the indoor relative humidity level.
Certain wooden instruments, like guitars and violins, can crack if the relative humidity is too low. A small, portable hygrometer, sometimes called a guitar hygrometer, can be used to make sure such items are stored safely. Indoor hygrometers can also be used to maintain the right environment in areas where items like old books, cigars, and food are stored. In saunas, an indoor hygrometer is used together with an indoor thermometer so that heat and humidity can be monitored. Indoor hygrometers can also be used to ensure that activities that are affected by humidity levels, like painting, can be performed under optimal conditions.