We purchased this to improve the air quality in our home.. We have a dog and a cat (they both shed quite a bit) and we also both suffer with seasonal allergies. Generally we keep it in our living room / kitchen area but it is small enough that you could easily move it into different rooms throughout the week. On the lowest setting the sound is almost undetectable, great for a bedroom! Level 2 & 3 do have a sound of the air flow but it doesn't disturb us. We typically turn it up to the highest level (3) when we leave for the day and then keep it at level 2 while we are home. The internal filter is supposed to last an entire year and the outer filter layer can be cleaned as needed. So far we love it and we can see in the filter that it is working! I will update this later if our experience changes.