Using air filters alone cannot guarantee adequate air quality, especially when there are significant sources of pollutants and insufficient ventilation. You can purchase approved air purification systems that are specifically designed to remove dust, mold, bacteria, and viruses from the air. When used correctly, air and HVAC filters can help reduce airborne contaminants, including viruses, in a small building or space. Therefore, implementing an air filtration system or air purifier can help these community service facilities reopen to the public during the ongoing pandemic.
The Environmental Protection Agency (EPA), American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and Centers for Disease Control and Prevention (CDC) recommend upgrading air filters to the highest possible efficiency that is compatible with the system and verify filter fit to minimize filter air bypass. Heat Recovery Ventilation (HRV) systems exchange stale indoor air for outdoor air while transferring heat between exhausted indoor air and incoming outdoor air. Many manufacturers use the Clean Air Supply Rate (CADR) rating system to evaluate air filter performance. Always consult your forced air system manual or an HVAC professional to check which filter can handle your home system.
Use protection when changing the filter, as particles inside the filter may contain live viruses. It's important to note that Minimum Efficiency Reporting Value (MERV) and High Efficiency Particulate Air (HEPA) are two different types of air filters, although you've probably seen both related to air filtration. Upgrading to a filter with a higher MERV rating can help reduce the amount of small particles in the air. For the European standard, a True HEPA filter will filter the air and capture at least 99.95% of particles 0.3 microns in size.
The only way to effectively remove particles from the air is with a system that circulates air continuously. DIY air purifiers can provide some benefits for reducing concentrations of viruses and other indoor air pollutants, but research is limited and there are several important considerations explained below. Before making any changes to the air filter of an HVAC system, users should consult their HVAC manual or an HVAC professional. When it comes to protecting yourself from Covid-19, it is important to understand how an effective furnace filter can help reduce airborne contaminants in your home or office space.
The best furnace filter for Covid-19 is one that has a high MERV rating and is compatible with your HVAC system. A True HEPA filter is also recommended for European standards as it can capture at least 99.95% of particles 0.3 microns in size. It is also important to consult your HVAC manual or an HVAC professional before making any changes to your furnace filter.