Cleaner indoor air can be yours even if you don’t have an HVAC system. The Filtrete Room Air Purifier device and its filter help reduce airborne particles in the air you breathe. This energy star-certified stand-alone unit works well in medium-sized rooms and includes a Filtrete True HEPA Filter that captures 99.97% of particles you can’t see, such as mold spores, pollen, pet dander, and more. As small as 0.3 microns from the air passing through the filter media. Initial efficiency value.