Re: huh? buy tanks of O2?

 May I ask your opinion on this kind of unit?

http://cgi.ebay.com/Air-Purifier-IONIC-Filter-OZONE-Machine-Negative-IONS_W0Q...

That is a hot corona system, which I am not fond of but that is all you are going to find for a higher output air purification unit. I have seen some UV units for air, but these are very weak compared to corona discharge and do not have adjustable outputs. I have never seen a true cold corona unit for air purification although I have seen plenty of companies claims their air purification units are cold corona when they are actually hot corona. The main difference is that hot corona devices generate acids when air is used as where cold corona does not. I have made a few prototypes for a cold corona air purification unit and they work great. So I am hoping one day to find a company with the means to have these made commercially.

As for the unit you linked they are pretty much the same as the other air purification units I have seen in concept, just shaped differently. Again cold corona would be my first choice, but since these are not available to my knowledge for air purification this kind of unit is better than nothing. The trick to using these kind of units  is to keep them up high as you can. Ozone is heavier than air and will sink. You want the ozone to blow out then sink down. As it sinks the ozone will react with particles and gases in the air breaking a lot of it down before reaching face level.