What is the maximum runtime and room coverage of the UHE-CMTF91?

The humidifier can run up to 70 hours, based on the mist level set to the lowest setting. The unit is designed to cover rooms up to 426 ft² / 39.5 m², based on AHAM HU-1-2016 measurement as shown by independent laboratory testing. Runtime may vary depending on the natural humidity level in your home, water temperature, and mist-level setting. (Page 11)