As the season changes, it’s likely time for a furnace filter change as well. One reason for a furnace filter is to protect the blower fan from dust and other gunk the return air duct pulls into the furnace unit. More important is that the filter manages the air quality inside your home as it removes contaminants from the air to be circulated.
As important as changing a furnace filter regularly, is putting In a quality filter. Furnace filters come in a variety of types. At the inexpensive end are disposable fiberglass filters that only trap large dust particles. On the other side are HEPA (High-Efficiency Particulate Air) filters that are rated 99.97% successful at trapping minute particles.
Furnace filters are rated using the Minimum Efficiency Reporting Value (MERV). MERV ratings range from 1 to 16. The higher the rating the finer the particles the filter should remove.
Filters with very high MERV ratings tend to be more expensive and are a good investment for allergy sufferers. A MERV rating between 5 and 11 is adequate for most homes.
Filters with a higher MERV rating also allow less air to flow through forcing a furnace to work harder. Check what the furnace manufacturer recommends as the maximum MERV rating for your model of furnace.
TIP: When installing a filler look for the arrow which shows the direction of airflow. Also mark the date of installation on the filter.