Easy to replacement and does play an important part in asthma. I can breathe cleaner air when I'm relaxing n sleep in the bedroom, so that means less coughing.
I have endured a cough since 2019, particularly at night. I bought my machine and placed it the night stand. NO coughing ALL night. My husband could not believe the quiet night’s sleep. It took 3 nights before I finally realized this really works. I have used it nightly for over 3 months. I highly recommend it. Try it. What have you got to lose?