Pollen is everywhere. We got so much in the house from just a day of having the sliders open that my husband could barely breath that night. So we ordered a fancy air filter, which wasn't cheap, but it's hard to put a price on breathing without pain or a good night's sleep. Anyway, the weirdest thing about it is that since I have no allergies, I can't actually detect that it's working. I feel like I'm lacking a sense when my sweetheart talks about the air quality being good or bad, the air filter doing its job etc, because to me there's absolutely no difference. I'll be interested to try this thing out when friends with pet allergies visit! Oh and if you're wondering, we got this one.