Bought a Breathsmart with a HEPA FreshPlus Filter for our bedroom when the smoke was thick from California wildfires last year. An investment to be sure, but one year later I could not be happier. Ordered a replacement BF35-VOC filter with a pre-filter pack of 4 today. The prefilter gets very very dirty, so I now plan to change then quarterly. Saving for a second filter for downstairs.