There are a variety of different types of filters available for filtered centrifugal supply ventilators, including: - MERV filters: MERV filters are rated on a scale of 1 to 16, with higher numbers indicating better filtration. MERV filters are effective at removing dust, pollen, and other particles from the air. - HEPA filters: HEPA filters are the most effective type of filter available for centrifugal supply ventilators, and they are capable of removing 99.97% of particles from the air.