When it comes to air filters, the Merv 13 is one of the best on the market. It is capable of trapping all typical airborne contaminants, including smoke, smog, and even virus carriers. It is electrostatically charged and constructed of materials that are more efficient than standard polycotton pleated filters or fiberglass filters. In fact, it is so effective that it can filter particles that are less than one micron in size.
The MERV rating system was developed by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) to fairly evaluate different quality air filters. A MERV 13 filter will trap dust, pollen, mold and bacteria at a rate between 84.9% and 90%. It is also able to capture 65% to 79% of the smallest particles that a MERV 11 or MERV 8 can't. However, it's not as good at capturing small virus-sized particles as a HEPA can.
A MERV 13 will trap less than 75% of air particles that are 0.3-1.0 microns in size (coronavirus is 0.1 microns). Therefore, if your household includes someone older than 65, younger than 5, or anyone with a compromised immune system, you should get the MERV 13 filter to get the extra protection it will give you. It is also difficult for many existing HVAC (HVAC) systems to adopt a MERV 13 because of the increased fan load of finer filter media, which can actually cause more harm than good and reduce airflow if your system is not designed to handle that type of filter. On average, many installations are limited to one type of MERV 8 or MERV 9 filter. Good MERV sorting efficiency will improve indoor air quality and reduce the spread of virus particles. If your home's HVAC system is unable to handle MERV 13, opt for a filter with the next highest possible rating.
Read the EPA “Home Air Purifier Guide” for information on how to place and operate a portable air purifier.
