I purchased two PureZone 3-in-1 True Hepa Air Purifiers on 11/30/2022...one for each of my tiny school nurse offices. I needed something small and with a low profile to filter the air where ALL the sick students come to visit in my under-ventilated tiny office. They have worked well in the short time that I have been using them. The high mode definitely puts out good circulation and provides quite a bit of white noise. The medium and low cycles are almost silent, but I can definitely feel increased air circulation in high mode! I am happy with them, especially if they last the duration of the 5 year warranty! I am hoping that they help with better air quality and less respiratory infection transmission:)