We recently got a dog, we have 3 kids, and our house isn't huge. We set this up in our dining room which is open with the kitchen. It kicks on every time we cook using the stovetop. It's amazing how much goes into the air! We were a little disappointed to find that in general, our house isn't really that bad when it comes to "stuff" in the air. It's actually a good thing. We'll see though when all the windows are shut during the winter. It does not take long for the filter to clear the air, it goes into the red and then within a couple minutes it's down again. We just set it to auto and let it run which it great. It's super quite, I've never noticed it, sometime I put my hand over it just to make sure it's still moving air.