When it comes to protecting your family from airborne contaminants, it's important to understand the differences between Merv 13 and HEPA filters. MERV stands for Minimum Efficiency Reporting Value, and it is a rating system used to measure the effectiveness of air filters. A MERV 13 filter is designed to capture particles between 0.3 and 1.0 microns in size, while a HEPA filter can capture particles as small as 0.3 microns. This makes HEPA filters more effective at capturing small virus-sized particles, such as those found in the coronavirus. On average, many installations are limited to one type of MERV 8 or MERV 9 filter.
However, with the recommendation of a Merv 13 or higher, does a MERV 13 filter meet your needs? A MERV 13 filter is a step in the right direction and captures more particles than a typical MERV 8 filter. Unfortunately, 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). It is also difficult for many existing HVAC (HVAC) systems to adopt a MERV 13 because of the increased fan load from 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. MERV filters 9-12 provide excellent filtration for homeowners, but can be costly if you need to change filters frequently.
Merv 13 air filters even provide additional filtration power against fine particles compared to MERV 11 filters. The MERV rating of an oven filter represents its ability to filter air pollutants; a filter with a lower MERV rating could trap fewer particles and contaminants compared to one with a higher rating. In general, filters with a MERV 16 rating or lower are considered HVAC system grade filters for residential, commercial, and general hospital use. MERV 17 to MERV 20 filters are commonly used in operating rooms, cleanrooms and other settings that require absolute cleanliness. A MERV 8 filter can still handle lint, dust and pollen when spring comes, but you won't have to worry about dust mites or mold in your home. In standard cases, a MERV 8 air filter is considered a more than adequate option, but it may not be enough when it comes to combating increased outdoor air pollution, pet fur and dander, or asthma and allergy triggers. Considering the threat posed by the spread of COVID-19 and other germs, upgrading a building's air filter to a HEPA is a much more effective step than just a MERV 13 considering the small size of a virus (0.06-0.12 microns); the more efficient the filter, the better.
A MERV 11 filter traps all that, plus pet dander, smoke, smog, and air from coughs and sneezes. When choosing an air filter for your home or business, it's important to consider both cost and effectiveness. While available, a MERV 20 filter is best suited for cleanrooms and commercial use where maximum filtration is required, not necessarily for your home. Ultimately, understanding the differences between Merv 13 and HEPA filters will help you make an informed decision about which type of air filter best suits your needs.