While rated for a medium-sized room, this machine will handle larger spaces if left running continuously - even at the lowest speed. That assumes normal living habits. I am a smoker and will not give up my cigars for anything. Wife and kids do object. However, with the machine running and filter in good condition those objections are few and far between, Upon bringing it home I was bothered by a drone emanating from the cleaner. On close inspection with a flashlight I could see the (turbine) fan wobble. The wobble coincided with the fluctuating drone. First thoughts were to go in for warranty service. Then, I figured I'd take things in my own hands: - Dis-assembled the cleaner - three screws visible on top plus another 4 screws buried behind the filters. Noticed the fan was plastic and of pretty flimsy construction. Removed the fan; -Re-installed/re-seated fan with the fixing nut not too tight. Factory had the fan tightened down to an extent where the plastic got distorted. That resolved the subtle, haunting, fluctuating hum that was distracting me. Now, it is the way it should have been - with a consistent sound of air-flow. Frankly, this machine operates on exacly the same principle as utilized by some costlier units I have owned. Efficiency is at par. Ion function is useless - a carry over sales 'feature' from fads of the past One last thing: when the carbon filter is clogged it has also lost its innate ability to purify air. No amount of vacuuming will help. When its worn, it is dunn. Replacement sheets of similar carbon element can be purchased on the cheap, off the web. Just cut them to size, ensuring proper fitment and total coverage. Oh, I do miss a remote. Purchased a $10 plugin receiver that turns the machine on and off remotely - available at the local hardware store.
Cancelled my online order when I hadn't received my two air purifiers after eight days. Called local Sears store and they were no help. No wonder Sears is going under.
Has an ion button. Nice.