Healthy indoor air quality
How to keep wildfire smoke out of Homes with mechanical ventilation systems?
...Filtering can also help control air pollutants, but only if the filter is adequate. According to the US EPA, a HRV or ERV unit filter must have a Minimum Efficiency Reporting Value (MERV) of 13 to provide effective protection against particulate matter in the air we're going to breath inside a home or office building i...