High-efficiency air filters
High-efficiency air filters are typically installed in HVAC systems to trap particles in the air that are being sucked into the system. High-end HEPA filters can successfully remove 99.97% of airborne particles, including virus particles.
The main complication of adding HEPA filters to existing HVAC systems is, ironically, because of their efficiency. They collect so many small particles that they require regular maintenance and replacement. Additionally, HEPA filters can also cause changes in air pressure, depending on your particular HVAC setup.
Electronic air filters
Electronic air filters can use a variety of methods to help remove particles from air or render pollutants incapable of causing harm.
Some HEPA filters can be installed in portable units, but to be effective, they must be appropriately sized for the room and airflow must be designed to ensure all air in the room passes through the filter regularly.
Air scrubbers and ionizers
Some electronic air filters are called air scrubbers and use PCO UV lights: ultraviolet lights are shone inside a titanium-coated system to help clean the air. Other electronic air cleaners are called ionizers and work by encouraging the particles to attach themselves to a filter substance.
Ozone
A by-product of both air scrubbers and ionizers is ozone, which can also be an air cleaner. However, the amounts of ozone required to be effective are themselves considered a pollutant.
