The Hunter QuietFlo Air Purifier is great for cleaning the air in single rooms. It's really powerful and fast. Within minutes after turning it on you can breathe the results. It cleans the air as it suppose to. If you are looking to clean the air in multiple rooms then this will not work for you. While cleaning the air it also gives off cool air which is great to use alone or in addition to a portable air conditioner. My cat does not seem annoyed of bothered when it's running. Considering the size of this unit it does freshen the air really well. I like it and I often use it to help me sleep. Ease of Maintenance Filters are really easy to change and last a long time even in really dusty places. Dust/Allergen Removal Within minutes the air smells fresh and fells cooler. Filter Availability I usually find my filters on Ebay without any problems. Durability It's well made and will last for years. Effectiveness It works for a single room. It does not work for multiple rooms. Design It takes up little space and fits on a table easily.