Medical institutions often use filters with a MERV 13 rating, which can effectively capture bacteria, mold spores, pet dander, smoke, vehicle fumes, viruses and other microallergens of 1 millimeter or more. According to this table, “if the entire indoor air quality spectrum of commercial buildings is taken into account, the preferred product should be a filter with an efficiency of MERV 13 or higher”, as advised by Thornburg. This greater efficiency will also serve to combat mold spores present in the air.MERV 13-16 filters are the highest possible ratings for average residential filters and can capture particles as small as 0.3 microns. These filters can capture mold, smoke, and smaller contaminating allergens, as well as particles of bacteria and viruses.
MERV 13-16 filters rank higher because they are more effective at capturing and filtering larger particles.The MERV 13 air filter is one of the best filters on the market. These traps all of the typical air contaminants, including several more. While a MERV 13 filter can trap dust, pollen, mold, and bacteria, it can also filter smoke, pollution, and even virus carriers. In fact, there aren't many particles suspended in the air that a MERV 13 air filter can't trap.
It would also be very effective against bacteria since “98% of all bacteria known to man measure more than 1 micron and MERV 13” is more than 85% effective on particles of 1 micron.For common household airborne particles such as pet dander and mold spores, the MERV 13 air filter is an excellent choice for many homeowners. A value higher than MERV 13 will severely restrict air flow to the air conditioning system and could damage the system. However, air filters with such a high rating from MERV 16 to MERV 20 are usually only found in hospitals and nuclear power plants where air filtration is essential.A MERV 13 filter with six air changes per hour would be “practically 100%” efficient when it came to capturing all the molds indicated in the graph according to Seyffer. If you are still not sure if you want to change to a MERV 13 air filter, know that it is the official filter recommended by ASHRAE.
If you have allergies, pets or live near smoke pollution, choosing a MERV 13 filter is the ideal choice.