When it comes to protecting yourself and your family from the novel coronavirus, air and HVAC filters can be a great help. Canadian public health guidelines related to COVID-19 have been updated as our understanding of the virus has improved. We continually review tests and work with partners across the country and around the world to ensure that we are using the most current and highest quality information available. Research has shown that upgrading to a filter with a higher MERV rating can help reduce the amount of small particles in the air.
It is important to consult your forced air system manual or an HVAC professional to check which filter is suitable for your home system. HEPA filters are designed to improve indoor air quality by physically removing small particles of matter, such as dust, pollen, and pet dander. Surprisingly, a team of researchers did not find many viral particles in the ICU room air, even when the filter was turned off. However, when they turned on two HEPA air purifiers that met the Environmental Protection Agency (EPA) recommended Clean Air Delivery Rate (CADR), overall exposure to simulated exhaled aerosol particles was reduced by up to 65% without universal masking.
The researchers collected air samples from the rooms for a week when the air filters were on and two weeks when they were turned off. In the general room, they found SARS-CoV-2 particles in the air when the filter was turned off, but not when it was turned on. This suggests that air filters could be used to reduce the risk of patients and medical staff contracting SARS-CoV-2 in hospitals. It is important to make sure your home's forced air system filter is properly sized to prevent air leaks around the filter.
By itself, cleaning or filtering the air is not enough to protect people from COVID-19, but when used correctly, it can help reduce airborne contaminants, including viruses, in a small building or space.