The answer to 'how often to replace humidifier' is that most residential humidifiers should be replaced every 1-2 years, depending on usage and water quality. Humidifiers work by adding moisture to the air, and over time the internal components can become clogged with mineral deposits, mold, and other contaminants that reduce their efficiency and can even release unhealthy particles into the air.
To ensure your humidifier is working properly and providing clean, healthy moisture, it's recommended to replace the entire unit every 12-24 months. This will prevent buildup, maintain optimal performance, and protect your indoor air quality. Be sure to follow the manufacturer's instructions for proper maintenance and replacement intervals.