Thank you for your feedback on our humidifier. We're glad to hear you like its design, quiet operation, and easy top filling. We understand your concern about the frequent refills. The runtime can vary based on humidity levels and settings. For the best performance, we recommend placing the humidifier in a room up to 500 sq. ft, adjusting your preferred target humidity level, and setting the humidifier to Auto mode. This allows the device to react to changing humidity and adjust to meet your target level. Initially, it will consume more water to increase the humidity, but once the target is reached, it will use less water to maintain it. If you have any further questions or need assistance, please don't hesitate to reach out. We're here to help!,Blueair,Blueair Team,clientresponse