I needed something for my basement air quality.  I did a lot of research an I found this Shark with a true hepa filter capturing 99% of harmful air particles.  It also has a heater which can heat a 1000sq ft room.  The controls are easy to used and it is very quiet.  I can also just put it on the fan mode just for air circulation.  The filter will last a long time 6-12 months.  Excellant product and comes with a 2 year warranty.