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Home  /  Blog  /  Air Purifier Filters & What They Do
Levoit Blog
Air Purifier Filters & What They Do
October 03, 2022   |    3 min read
Home  /  Blog  /  Air Purifier Filters & What They Do

Since their invention, air purifiers have become one of America’s favorite household essentials. People can cozy up in their homes, regardless of outdoor pollution levels, and know their personal air supply is clean.  


To shed light on how they work, we've compiled a few key points about our 3-stage H13 True HEPA filtration process.


What do pre-filters do? 

Pre-filters are the first layer of defense. They catch large airborne particles, such as: 

  • Hair 
  • Pet fur 
  • Fibers 
  • Lint 


This helps protect and extend the life of the HEPA filter, since HEPA filters are made to trap very fine allergens and would quickly get clogged or damaged by these larger particles. Pre-filters are made with a variety of materials, including nylon, material containing activated carbon, and fine woven fabric.  

What do HEPA filters do? 

HEPA filters are the second layer in our 3-stage filtration process. HEPA stands for High Efficiency Particulate Air (filter). To be classified as H13 True HEPA by the U.S. Department of Energy, the filter must trap at least 99.97% of airborne particles 0.3 microns in size. Particles such as: 

  • Fine dust 
  • Pollen 
  • Pet dander 
  • Smoke particles 
  • Mold spores 
  • Bacteria 
  • Viruses 


When enhanced with HEPASmart™ Technology, our H13 True HEPA Filters use statically charged fibers to help capture: 

  • 99.9% of viruses 
  • 99.99% of bacteria & mold 


HEPA filters are typically made of fiberglass or plastic polypropylene. The air purifier pushes air through the filter where very fine particles get caught and trapped. Those with health conditions such as asthma or allergies, can especially benefit from an H13 True HEPA filter.  


What do activated carbon filters do? 

Activated carbon is a highly porous material, making it an excellent filter for the final stage. The adsorption process is like crumpling up sticky tape and blowing air through it—as the air passes through, gases stick to the carbon and don’t get released back into your air. Activated carbon filters help neutralize pollutants such as: 

  • Smoke 
  • Household & pet odors 
  • Volatile organic compounds (VOCs) 
  • Fumes 
  • Formaldehyde  
  • Benzene 
  • Ammonia 
  • Hydrogen sulfide 


This carbon typically comes from burnt coconut shell, which has been put into a mesh filter. An activated carbon filter is classified as “high-efficiency" based on the weight of the carbon. The more carbon (the heavier the filter is), the better the filtration and the longer the filter will last. This filter is especially useful for those in areas with lots of car exhaust fumes, wildfire smoke, and other kinds of airborne pollution. 


Levoit’s exclusive ARC Formula® is a treatment for our Custom High-Efficiency Activated Carbon Filters. It is especially helpful for pet and cooking odors, chemically decomposing molecules trapped within the filter to prevent oversaturation and secondhand pollution. 


Which filtration system do you need? 

From our Levoit Core® series, pick the replacement filter that best matches your unique preferences.