We haven't noticed much change in our room.
We purchased this product to clean the air in our bedroom.  Both dogs sleep on the floor in our carpeted bedroom.  I really haven't noticed much of a change in the smell.  We also placed it by our laundry hamper.<br /><br />There are no filters to clean and so it is hard to think of it doing it's job.  It's kind of like the bagless vacuums.  I love them because I can see the dirt it picks up.  I can quantitatively see the dirt and feel good about how well my vacuum is working.  With this device, unless there was a smell that went away, it's hard to determine how well it's working.
Rating: 4 stars