ASHRAE states: “MERV 13 filters are efficient at trapping viruses, including COVID-19”. Upgrade your MERV 8 prefilters to MERV 13 without changing your fan or redesigning your filter rack! Our MERV 13 pleats are high capacity with minimum restriction to airflow and has a 30% higher dust holding capacity, provides exceptional MERV 13 efficiency and peace of mind. Each MERV 13 pleat is antimicrobial and will not promote biological growth.