{"id":5579,"date":"2026-09-16T10:55:21","date_gmt":"2026-09-16T15:55:21","guid":{"rendered":"https:\/\/atipure.com\/store\/?post_type=avada_portfolio&p=5579"},"modified":"2026-09-23T14:45:08","modified_gmt":"2026-09-23T19:45:08","slug":"indoor-air-should-not-be-too-humid","status":"publish","type":"avada_portfolio","link":"https:\/\/atipure.com\/store\/portfolio-items\/indoor-air-should-not-be-too-humid\/","title":{"rendered":"Indoor Air Should Not be Too Humid"},"content":{"rendered":"

Dry indoor air can cause or worsen symptoms such as dry skin, irritated eyes, a dry throat, and irritation of the nasal passages. These problems are particularly common during winter in cold climates because heating indoor air lowers its relative humidity. Low humidity can also contribute to static electricity and the drying or cracking of some wood products and building materials.<\/p>\n

Many households use humidifiers to increase indoor humidity. However, adding moisture to indoor air must be done carefully. The U.S. Environmental Protection Agency (EPA) generally recommends maintaining indoor relative humidity between 30% and 50%. Keeping humidity within this range can help avoid both excessively dry conditions and the excessive moisture that encourages mold and other biological growth.<\/p>\n

Excessive humidity can create its own indoor-air-quality problems. Condensation on windows and other cold surfaces can provide moisture for mold growth, while persistently damp conditions can encourage dust mites and other biological contaminants. Mold and dust mites can aggravate allergy and asthma symptoms in susceptible individuals.<\/p>\n

Different types of humidifiers work in different ways. Common residential types include ultrasonic humidifiers, impeller or cool-mist humidifiers, evaporative humidifiers, and steam vaporizers. Their effects on indoor air quality can differ significantly.<\/p>\n

Ultrasonic and impeller humidifiers can disperse minerals present in tap water into the air along with the water droplets. Depending on the water supply and the device, this can produce a visible mineral dust and increase concentrations of particulate matter indoors. These devices can also disperse microorganisms if the water reservoir is contaminated. The EPA recommends using low-mineral or distilled water in ultrasonic and impeller humidifiers and cleaning the units regularly.<\/p>\n

Evaporative humidifiers use a fan to draw air through a wetted wick, filter, or other evaporative material. Because minerals and other impurities are less readily carried into the air during evaporation, these units generally produce less mineral aerosol than ultrasonic or impeller humidifiers. The wick or evaporative material nevertheless needs regular maintenance and replacement according to the manufacturer’s instructions.<\/p>\n

Steam vaporizers and other steam humidifiers heat water to produce steam. Because most minerals remain behind when water is boiled, they generally release fewer minerals into the air than ultrasonic or impeller models. However, hot water and steam can cause serious burns, so these devices should be kept away from children and other people who could accidentally come into contact with hot water or steam.<\/p>\n

Regardless of the technology used, no humidifier should be considered maintenance-free. Standing water can provide an environment for microorganisms to grow, and a poorly maintained humidifier can therefore make indoor air quality worse rather than better. Humidifiers should be emptied, cleaned, and dried regularly according to the manufacturer’s instructions. Water should not be allowed to remain stagnant in the unit between uses.<\/p>\n

A humidity monitor, or hygrometer, can help determine whether a humidifier is actually needed and prevent excessive humidification. Rather than operating a humidifier continuously, users should monitor the relative humidity and adjust the device accordingly. If condensation begins appearing on windows, walls, or other surfaces, the humidity level may be too high.<\/p>\n

People who develop new or worsening respiratory symptoms while using a humidifier should stop using the device and investigate whether it is contributing to the problem. Persistent or severe respiratory symptoms should be discussed with a healthcare professional.<\/p>\n

A humidifier can be useful when indoor air is excessively dry, but adding moisture is not automatically beneficial. The goal should be to maintain a moderate relative humidity while keeping the humidifier itself clean and preventing moisture accumulation in the building.<\/p>\n

By Michael Chiu, MWS, CI
Previously published in Ming Pao Daily News – Updated and Revised in 2026<\/span><\/i><\/p>\n<\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"portfolio_category":[211],"portfolio_skills":[],"portfolio_tags":[],"class_list":["post-5579","avada_portfolio","type-avada_portfolio","status-publish","format-standard","hentry","portfolio_category-knowledge-center"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t