Review on ✨ Optimized for SEO: PureGuardian H4810AR Ultrasonic Warm & Cool Mist Humidifier, 120 Hours Runtime, 2 Gallon Tank, 600 Sq. Ft. Coverage, Large Room – Silent, Filter-Free, SilverClean Treated Tank, Essential Oil Tray by Ashley Santiago

This Guardian Model H3810 humidifier was purchased in March 2018 for use in a large room measuring 14 x 12 x 10 ft H with two open corridors connecting to the room. Without humidification, the humidity in the room is 25%. The humidifier has 3 speeds and runs at high speed with cool mist. A full 2 gallon tank will last approximately 22 hours when run at high power in the space described. As a result, the humidity is around 36%. As mentioned in other reviews, a filled tank is difficult to manage and install properly on the base of the humidifier. Also, the tank cover must not be too tight, otherwise the water may not flow properly to the base of the humidifier, causing the full indicator to light up and the humidifier to stop.