At a minimum, a MERV 13 filter traps less than 75% of air particles that are 0.3 to 1.0 microns in size. Its efficiency is at least 90% when the particles increase from 3 to 10 microns in size. This economical option works to prevent contaminants from spreading throughout the building. But is it enough to provide complete protection?The MERV 13 filter has thick, high-quality folds that filter out almost all harmful particles, while minimizing system backpressure and allowing indoor air to flow smoothly.
It also uses an electrostatic charge to remove fine particles, such as those that can carry viruses. However, many existing air conditioning (heating, ventilation and air conditioning) systems find it difficult to adopt a MERV 13 due to the greater load on the fan caused by the finer filter media, which can reduce airflow if the system is not designed to withstand this type of filter. 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 simply to a MERV 13, considering the small size of the virus (0.06 to 0.12 microns). A HEPA filter traps the smallest particles at a faster rate than even MERV 16 and are typically used in surgical operating rooms, clean rooms, and other settings that require absolute cleaning. In addition, due to logistical problems and the high cost of installing a higher MERV filter (such as MERV 1) in the existing HVAC system, both the CDC and ASHRAE recommend adding commercial quality portable HEPA air purifiers with the ACH (hourly air change) appropriate for the space. In conclusion, while a MERV 13 filter offers some protection against airborne contaminants, it is not enough for complete protection against viruses like COVID-19. For this reason, it is recommended that you upgrade your air filter to a HEPA filter for maximum protection.
