I just started research for purchasing an air purifier and it is confusing. The ionic ones are more controversial and all the more legit resourse lean towards HEPA. And, I ordered a cheapo one off ebay -just to check it out before I spend more money. I would have been better off going to Wallyworld - easier to retirn. I haven't gotten the purifier yet, but I can post back. My guess is that I'm getting what I paid for (cheap). Here's a link to one that I thought seemed good - and I wanted to hit the local stores to compare pricing, etc. [ please do not post commercial websites - use brand names only ] Good luck -Pam