Other things to consider: the output of the IQAir is redirected horizontally in a circle around the machine by a flat cover. The air that comes out is turbulent. Turbulence is bad because it mixes filtered and dirty air so it takes longer for dust to be brought to the filter. I described in another post how another air purifier I tried was more effective in reducing the particle counts in the room. By removing the top cover on the IQAir, particle counts in the room came down much faster because the air then wasn't turbulent. Also note that IQAir accessories are ridiculously priced, with little pieces of plastic selling for more than half of the price of the already very expensive whole unit. Recommendations for the IQAir by people selling it could be tainted by profit motives (although I respect BE's opinion). The top of the IQAir unit isn't flat so you can't put anything on it (such as a CPAP machine so it would send you filtered air). There's a little animated light that has an annoying hypnotic effect on the ceiling at night -- I had to cover it with black electrical tape. It takes a lot of room. I rarely ever use it anymore -- it's intolerably noisy at the speeds needed for it to be effective. Overall I think the IQAir is not a good value. I'd sell my unit with the set of extra filters (still new in their box) I bought if I could be bothered to find a buyer.