The features that integrate with your phone including clean cool or heated air, design and ease of maintenance are why this is my 4th fan unit from Dyson.  Not 4th due to breakdowns; 4 units in different rooms. When you consider the cost to purchase a Hepa type filter system for your home, the Dyson products make it an easy decision; Hepa filtration plus Heat, plus Cool all packaged in one.  Once you own one, you will know.