Investing in HEPA filters can be a great way to reduce allergens and airborne contaminants in the home. Few things are as important as the air we breathe, and HEPA filters are one of the most popular products available to help improve air quality. To understand if these filters are worth the money, it is important to understand what they can (and can't) do, as well as what to consider when buying a HEPA air purifier. The Department of Energy (DOE) specifies that HEPA filters used by DOE contractors must be able to remove 99.7 percent of airborne particles of 0.3 microns or larger.
Manufacturers of high-quality HEPA filters voluntarily test and certify their filters to meet DOE standards, labeling them “absolute HEPA” or “true HEPA”. Those that do not meet DOE specifications are often labeled as “HEPA-type”, HEPA-type, or “HEPA-type”. In order to control COVID-19 and reduce airborne transmission rates, air purifiers equipped with HEPA filters can play a role when used in homes and public environments, such as waiting rooms. However, users should not assume that an air purifier equipped with a HEPA filter will fully protect them against infection.
Along with other precautions, such as wearing masks, washing hands frequently and maintaining social distancing, air purifiers equipped with HEPA can help reduce the risk of infection. If someone in your household has allergies or asthma, investing in a household HEPA filter will help reduce and eliminate airborne particles that cause or may worsen symptoms. To understand that HEPA filters are effective in keeping homes safe, you need to understand how they are designed. A HEPA filter must be able to remove up to 99.97 percent of contaminants with a size of 0.3 microns.
A filter labeled “True HEPA” or “Absolute HEPA” has been tested and complies with high efficiency criteria. A whole-house HEPA air purifier connects to the main trunk of a home's HVAC intake duct and filters harmful contaminants every time the oven or air conditioner is in operation. It is important to note that frequent replacement of filters is essential, as allergens and other toxic materials accumulate in the filter. MERV-13 air filters are generally the best filter upgrade for residential use for typical HVAC systems.
While most allergenic particles are large enough to be trapped by a HEPA filter, very small fragments can penetrate the filter and remain in the air. Fortunately, the airborne particles that trigger allergy symptoms are relatively large in size and are easily trapped by a HEPA filter. Residential and home HVAC systems will most likely have to be modernized with new ductwork and equipment, perhaps even with an updated HVAC system that is powerful enough to work with and pass through a dense HEPA air filter. Activated carbon is almost always included as part of the HEPA filters sold today, which can help eliminate VOCs and ozone, but it has its own limitations.
Overall, investing in HEPA filters is worth it for those who want to improve their indoor air quality and reduce allergens and other airborne contaminants in their home. It is important to understand what these filters can (and cannot) do before making a purchase decision, as well as what type of HVAC system is needed for optimal performance. Additionally, it is important to remember that while these filters can help reduce the risk of infection from COVID-19, they should not be relied upon as the only form of protection against the virus.
