I bought a CIMR 2000 little over a month ago. I have a chronic cough from asthma and allergies. Once I turned on the unit it was about a day and could feel a major difference. My cough was almost gone and I felt as the air in my home was much easier to breathe. I watch my grand daughter and she has bad indoor and outdoor allergies. She always has a runny nose. While she is at my house she has no runny nose. This unit has helped my allergies and asthma to the point that I don't need to use my inhaler on a regular basis. This has been a life saver for myself and my grand daughter!!!!