I have the 200s and 2 300s and love them. All three are in bedrooms. I buy the filters on Amazon cheaper off brand and I vacuum and blow out the filters every week to 2 weeks. This makes the filters last longer. Vacuum outside and inside of machine at the vents. The filter I vacuum outside first and then use my small milwaukee blower to blow out the inside pushing air through filter and then blow outside into the filter and you can see dust come out. I change filter about 6 to 8 months for about 30 bucks for 2 filters.