I absolutely love our filter,I can smell,and see the difference in the quality of clean air in our apt,when our filter has not been used in days. It helps my son sleep better due to allergies, and my apt does not smell like puppies even though we have 2 dogs.I own 3 filters one for each room and the bigger one for the living room. I purchased the filters 2 years ago and I am very pleased with my purchase.