Toshiba Air Purifier up to 198sqft

I have to update my review. This thing works amazingly. I love all the features including the digital readout on the air quality monitor. Everything works great from the air output to how quiet it is to how it does automatically increase the fan speed when it detects any air quality problem. I love this, it was a great purchase. Seems to have very high quality engineering and materials, including compared to one from another brand I also tried. ‐-------- Incidentally, arrived lightning-fast in under two days, with regular shipping. Features, including timer seem to work. Reasonably quiet. I don't know how to measure its functioning as an air purifier. Recently, I have used a DIY box-fan homemade 'air purifier' with high-quality furnace filters, in a larger room - understandably, something of that size and nature made a more immediately noticeable difference in the air. But so far this seems like it has been a good purchase.