When it comes to air quality, those who prioritize it and may have to deal with asthma, severe allergies, and other similar conditions should opt for air filters with a MERV rating of 13 and above. Generally speaking, anything below a MERV 13 air filter should provide efficient air purification in a home without affecting airflow. On the other hand, air filters with a MERV 14 rating or higher are designed for commercial HVAC systems that can handle the coarsest filter material. The Minimum Efficiency Report Value (MERV) rating of an air filter is a good indicator of its effectiveness in your central HVAC split system. The higher the rating, the better the filter.
As the MERV rating increases, fewer pollutants and dust particles can pass through the filter, resulting in better quality incoming airflow. However, it should be noted that higher MERV ratings also mean greater resistance, which translates to less airflow. When researching HVAC systems, airflow is an important factor to consider. It is essential for the performance and longevity of your oven or air handler, as well as for providing a comfortable home. Generally speaking, our recommended MERV rating for oven filters ranges from 6 to 8 to achieve a great balance between maximum oven efficiency and home comfort. For instance, if an air filter can capture at least 20% of E1, 65% of E2, and 85% of E3 particulates, it will earn a MERV 11 rating.
With the lowest MERV rating (1-), the filter will still be able to capture pollen, dust mites, cockroach debris, sanding dust, spray paint dust, textile fibers and carpet fibers. A MERV rating is used to ensure that incoming vented air meets area-specific air quality standards. It should also be noted that filters at the lower end of the MERV scale are not even tested for efficiency in capturing E1 and E2 particulate matter. If the air filter is on the return grille inside the house, it should point towards the wall or ceiling. Air filters with higher MERV ratings may filter more particles but their thicker filter material may restrict airflow. According to ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers), this filtration helps provide healthier indoor air quality.
However, you may not get the air velocity needed to reach all parts of your house, leaving inconsistencies in temperature.