How Do Air Filters Trap Pollutants?

Excessive air pollutants in the home or workplace can create a hazardous environment and harm the health of everyone exposed to the pollutants. A high quality air filter is the best weapon against air pollutants as it traps the offending particles deep within the filter, removing them from the air we breathe. The effectiveness of the air filter at trapping pollutants depends on several different factors, including the kinds of pollutants present and the type of air filter purchased.

There are two main categories of air pollutants that can be removed from the air by air filters: particulate pollutants and gaseous pollutants. Particulate pollutants include small particles that are lightweight enough to float on the air, such as dust, pollen, animal dander, and mold. Gaseous pollutants typically generate from combustion processes and the use of products such as adhesives, cleaning products, paints, and pesticides. Some air filters are effective for both types of pollutants.

As the air flows through the filter, it removes the pollutants from the air by trapping them on the filter materials located within the filter housing. Gaseous pollutants are removed by using an adsorbent material – one that causes particles to adhere to a surface – such as activated carbon. The adsorbent property of carbon keeps these polluting molecules from passing through the filter with the air.

Different filter styles are designed to be effective for different types of pollutants so it is important to review what types of pollutants the filter is designed for before purchasing. Some filters are ineffective at reducing the concentration of pollutants for which they were not designed. No air filter is 100% effective at removing air pollutants from the home or workplace, but some air filters come close to that percentage for specific pollutants that they are designed to remove.

The effectiveness of an air conditioner filter is measured by the amount of the pollutant the filter is able to trap from the air stream moving through it. Most air filters are effective at capturing large airborne particles, but capturing small particles and/or gaseous pollutants may require a specific type or style of high quality air filter. The minimum efficiency reporting value (MERV) is the common measurement method used for rating the efficiency of air filters, allowing different styles and brands to be compared accurately.

A higher MERV indicates a higher percentage of smaller air pollutants removed from the air by the filter. An air filter with a MERV of 8 is much more effective at removing airborne particles than an air filter with a MERV of 3. Choosing a high quality air filter for your home or business is the best way to clear air pollutants out of the air and having a standard unit of measurement for all air conditioner filters helps.