Received the breathe smart this evening. Can’t believe that I could tell a difference in the air within an hour. Has been 2 hours now and the difference is remarkable. Just set it up in less than 10 minutes, turn to auto and let it do it’s thing. We have two English Bulldogs, one was added about 2 months ago, that have really had an impact on the air quality. In just these two initial hours I think I can live with two dogs now. BTW, I love my dogs & would not have thought about doing anything but keeping them.