There are basically three types of air scrubber filters, air purifier filters and dehumidifier filters.
HEPA Filters
High-Efficiency Particulate Air (HEPA) filters remove 99.97% of particles. These particles are 0.3 microns and larger. This makes quiet HEPA air purifiers ideal for removing small pet dander particles. They also do a great job with dust mite residue and pollen from your air.
HyperHEPA units are certified to work very effectively. They are far better than traditional HEPA air purifiers. They are known for the cleanest residential air possible.
Carbon Filters
Using activated carbon, carbon filters remove odors and chemicals from your indoor air. These odors and chemicals include cigarette smoke, fireplace fumes, and formaldehyde. Other smells include volatile organic compounds, pet odors, and kitchen odors.
The more carbon in each filter, the more odors they will remove.
Pre-Filters
These filters are a great benefit. They help extend the time between filter changes. They maintain the air purifier's functionality and efficiency. Pre-filters do this by trapping large particles. They never reach the primary filters of the air purifier.