Noticed a difference right away

We have two cats and alot of never-ending dust in our townhouse. My husband was waking up sneezing one too many times and so I suggested we get an air purifier. We work at a University and so I asked an Environmental Safety guy at our institution which one he recommended. He recommended the Whirlpool Whispure 510. We love it. The very first day we brought it home we put it in the bedroom and turned it on high for about three hours and then when we went to bed we turned it to low. Wow! What a difference! You could really tell that the air smelled and just "felt" cleaner. No more sneezing at night. And, oddly enough, the cats love it too...they just sit on the bed in front of it...breathing. I know that sounds weird but it's true.