Indoor air quality (IAQ) can significantly impact health and well-being, affecting how we live, work, and sleep. Numerous studies have indicated a strong correlation between IAQ and serious diseases, such as asthma, cardiovascular diseases, and cancer. Updated WHO guidelines for IAQ, coupled with recent research related to the COVID-19 pandemic and the transmission of airborne viruses, have greatly increased IAQ awareness. Room air purifiers are a simple and effective solution for improving IAQ in homes, offices, hotels, hospitals, restaurants, and commercial spaces.

What Is the Role of Filters and Filter Media in Room Air Purifiers?

Filters are the heart of room air purifiers as they capture airborne contaminants. Generally, manufacturers recommend air purifiers based on the room size. Room air purifiers are often tested against AHAM’s CADR standard or GB/T 18801, where a higher score represents a higher level of filtration. These standards are also used in combination with EN1822 or similar variants to state the level of particulate filtration (e.g., HEPA). 

Many room air purifiers are also designed to remove odors, VOCs, formaldehyde, and other gases. Electrostatic and ionizer filters are primarily used to remove particles. For molecular filtration, pleated filters with adsorptive filter media are recommended over loose-fill carbon cassettes to achieve proper filtration.

How Do Room Air Purifier Filtration Systems Work?

The filtration system in room air purifiers removes particulates, odors, and gases from the air. They use a fan to pull the air through the filter media and recirculate it back into the room. The level of air cleanliness is a function of the filter efficiency and the airflow rate. High efficiency, low pressure drop filters enable the highest air purifier performance.  

What Types of Filters and Filter Media Are Used in Room Air Purifiers?

Room air filters can be designed to filter particulates and gases (including VOCs and odors).


Particulate-only room air purifiers use a particulate filter to remove particulates from the air. The types of particulate filters used are: 

  • Mechanical filters. Mechanical filters use mechanical media, which utilize filter forces (diffusion, interception, and inertial impaction) to filter out particulates. The most common filter media used in mechanical filters is HEPA, which can be micro-fiberglass or synthetic Nanoweb® media. 
  • Electret filters. Electret filters use electrostatically charged synthetic filter media, such as H&V’s AlphaPerm® or Technostat®, in addition to mechanical filter forces. These filter media technologies utilize enhanced electrostatic charges to increase particulate capture with lower pressure drop.

Particulate, VOC, Gas, and Odor

Particulate, VOC, gas, and odor room air purifiers use a particulate filter and a molecular filter, usually made from activated carbon, to remove particulates, VOCs, gases, and odors from the air. The filters can be integrated in two ways: 

  • Two-stage. In the two-stage approach, the two filters remain distinct elements. The particulate filter is either a mechanical or electret filter in the sub-HEPA to HEPA range, while the molecular filter is a pleated media containing activated carbon.
  • Combined. Combi-filters combine particulate and gas-phase filtration media into a single filter. One composite filter media solution is used to serve both filter functions. 

Why Choose H&V’s Room Air Purifier Filter Media Solutions?

Hollingsworth & Vose manufactures a variety of highly engineered materials suitable for use in the filtration systems of room air purifiers. Products include sub-HEPA and HEPA particulate filter media and molecular filter media. Combi-media is also available for single filters that remove particulates, odors, and gases. Our differentiated air filtration media solutions ensure high removal of particulates and gases while keeping the pressure drop low, allowing for high flow rates with reduced energy consumption and noise levels. 

H&V products for room air purifiers include:

  • AlphaPerm®. AlphaPerm is a synthetic electrostatically charged composite media that offers low pressure drop in the efficiency ranges from H11-H13.
  • PerForm. H&V’s premium microfiber glass media offers best-in-class mechanical HEPA performance.
  • Nanoweb®. Nanoweb is a multi-layer synthetic composite with mechanical HEPA efficiency and the lowest pressure drop.
  • MFM. H&V’s molecular filter media can be combined with synthetic particulate filter media to offer both particulate and VOC, gas, and odor filtration or as a standalone filter. The media can be targeted to remove formaldehyde, ammonia, and acid gases, in addition to VOCs.
  • Technostat®. Technostat is a highly charged, high-efficiency media with a low pressure drop. It is often used in smaller air purifiers where space and flow rates are constraints.

H&V is a global leader in filtration. We provide advanced materials for creating a cleaner, healthier, and more sustainable world. For high-performance filters in room air purifiers, we provide sub-HEPA and HEPA particulate media to advanced molecular filtration combi-media. If you’re looking for innovative filter solutions that offer high efficiency, long life, and low energy consumption, contact us today. 

Product Search

View All Products