Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good Buy

So far I like this unit. I have not had to clean the filter yet and I am submitting this review 3 months after I bought it. It is not too loud, at least don't think so.I use it in my bedroom and have noticed that my nagging cough has disappeared and the air in the room appears to be actually cleaner to breathe in.This is my first air purifier/cleaner but I am very happy with my purchase. I did research long and hard before buying one and the need to not replace expensive filters was very high on my list.