Obnoxious fan noise.  Low CFM.  By default no ozone for better or for worse.  Some light leakage.
I actually got this for the intent of possibly gutting it and using it in another application, but first before doing that I've been using it in its intended manner.<br /><br />First, it does use a UV light and could potentially eliminate some of the *CAUSES* of odors like certain bacteria by k killing germs in any air that cycles through it.  But that UV light is, at least by default, one that only produces 254.3nm so does not produce ozone.  This means it won't really directly eliminate odors by actually binding with the particles in the air that cause them but can only do so indirectly by killing things.  There do seem to be some bulbs that can fit it that do produce ozone however, just these are third party and not official with the official ones not offering such an option.  On one hand, it is worth remembering that ozone can be as bad for you as it is to other things, but on the other hand, a 3.5W lamp wouldn't produce very much and should dissipate very quickly unless you're pretty much right on the thing (which you shouldn't be anyway!)  Since this is third party only (with most options not even shipping within the same country) I'm a little disappointed given the intended purpose of this (which is largely to clean the air -- especially of odors -- where ozone+UV would be much more effective than UV alone.)<br /><br />I definitely have to make a major complaint about its fan though.  I almost wonder if I got a unit with a bad fan or something because it makes a fairly awful noise.  It's not even so much that it's loud as that the noise is very obnoxious.  I think maybe the fan must vibrate too much or something, but I'm not really sure what exactly the cause of the noise is.  The fan doesn't seem to push as much air through as it really should (especially to be truly effective in even a relatively small room) so I'm definitely not happy with this part of its design at all.  Perhaps a "blower" type fan would be better for this sort of task.  One thing that can definitely be said though is that it doesn't push enough air to cover even a relatively small space very well and I wouldn't expect it to be terribly effective in anything bigger than a closet.  Perhaps if placed right over the sources of odors (like in the case of a litterbox for example) it might still be useful, but otherwise it probably isn't.  Of course, such a dinky fan has very little static pressure and they couldn't put any sort of filter over it, so it will pick up dust fast and tear up fairly quickly if placed too near to a litterbox anyway.  As obnoxious as its noise is, it might make a cat decide not to use the litterbox if it were there anyway.<br /><br />I also wonder a bit about the light leakage.  Near to the top it has plastic which carries some of the light intentionally and may be opaque to UV ranges so perhaps ok, but the holes at the top do not filter the light at all and nothing particularly blocks it, so the top lets the light through unfiltered.  Perhaps at this level it is not enough to matter.  I really can't be sure and so I may just be nit-picking here, but I do think they should have angled the output so the air could go around but the light would not given the potential for harm from the UV light.<br /><br />EDIT:  The more I use it the more I think it doesn't even work stock.  I've been sniff-testing it and get nothing really.  253.7nm light seems to produce something in the air that has a bit of a smell.  Not ozone (officially it breaks down ozone in fact) like 185nm light does, but all my real 253.7nm lamps produce a very strong and not very pleasant smell (which, if anything, is actually worse than the smell of ozone IMO.)  This, however, does not seem to.  I temporarily swapped in a bulb being used by a sterilizer that matched the specifications of this thing and suddenly could smell something obvious.  So I think the bulb that comes with it may just simply not be very good.  Most likely it requires one of those third party bulbs even to really do the job it claims to do.<br /><br />The incredibly obnoxious noise the thing produces is enough reason not to like it however.  The more I try to use it the more it begins to drive me crazy.
Rating: 2 stars