Minimum Efficiency Reporting Values, or MERV, reports a filter’s ability to capture particles. Filters with MERV-13 or higher ratings can trap smaller particles, including viruses. Many home HVAC systems will have a MERV-8 filter installed as the default. Upgrading to a MERV-13 rated filter, or the highest-rated filter that your HVAC system fan and filter slot can accommodate, could improve the system’s efficacy in removing viruses from circulated air. Before making any changes to the air filter in an HVAC system, users should consult their HVAC manual or an HVAC professional.