This allergen air purifier is exaclty what I needed for some of the rooms in my house. You don't wan't to have to deal with buying new filters every few months, and with this filter you don't have to. It is a hepa-like filter which means it reduces allergens at least by 99% I believe.
There are 3 speed settings, and the highest one is loud, if you like soft noise when you are sleeping this works. The quiet setting is pretty quiet, if you are in a very quiet room then you could probably hear it, but its quiet.
This is perfect for someone with pets as you can see how it sucks in the dander, hair and dust which only needs to be vacuumed every few months.

I highly recommend this allergen reducer!