My house is the cleanest I know of...I vacuum, mop the floor, clean my kitchen & bathroom sink, clean my shower stall, make my bed DAILY before I go to work. (it's a small house) I kicked it up by washing walls & my cupboarRAB, my curtains, doilys changed my 1250 furnance fitler and it still took 3 wks to rid my house of cat dander. I got a HPEA air filter; but the fan blow the air out so forcefully that I don't think it sucked an dander because it didn't help.:dizzy: