Overall, the best MERV rating for a home is between 8 and 10. These filters will capture a large portion of the particles in the air and improve indoor air quality without significantly increasing energy costs. In most cases, a MERV 11 air filter is suitable for residential use. Generally speaking, any filter with a MERV rating of 13 or lower should provide effective air purification in a home without affecting airflow. Meanwhile, air filters with a MERV 14 rating or higher are designed for commercial HVAC systems that can handle the coarsest filter material.
A MERV rating of between 6 and 13 typically meets the needs of most residences. This range offers a good balance between air filtration, airflow, and affordability. If you select an air filter with a MERV 13 rating, it can last up to six months before needing to be replaced. Overall, our recommended MERV rating for home filters ranges from 6 to 8 to achieve an ideal balance between maximum efficiency and home comfort.
We have the best options for portable air conditioners if a window unit or central air doesn't work for you. The air cleaner acts as a barrier between the HVAC system and the ventilation grilles, reducing the amount of air that can pass through the vents into the actual system. When removing the old filter, be sure to pay attention to the direction of the arrows on the filter to know which way the air cleaner should go in. Manufacturers' concerns are likely somewhat cautious, partly because recent innovations in air filters allow for high MERV ratings (11 to 1) with low pressure drop.
Air filters with higher MERV ratings can filter more particles, but the thickness of the filter material can restrict airflow. ASHRAE 52.2 describes methods and procedures for evaluating the performance of air filters based on particle size. Activities such as renovating the house, leaving outside doors open, and having children play around the house can speed up the buildup of dust and particles in the air cleaner. Since a high MERV rating means more particles will be removed from the air, you may first think about using only air filters with the highest MERV rating.
Obtaining filters with the correct MERV ratings is essential to ensuring that the air is well filtered without overloading the HVAC system. When an AC fan is started, air movement can cause the filter to crash into the interior of the unit if it is not properly secured. Most air cleaners have an arrow marked to indicate which direction the air should flow. When an air filter is dirty, less air can travel through the HVAC system, increasing operating times and reducing efficiency. Based on these characteristics, a MERV 8 is considered superior filtration compared to filters with lower MERV ratings.
It was established by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE). These are installed on wall-mounted return air grilles (more common in southern states) or on an air handler (more common in Mid-Atlantic and North Atlantic states where an air handler is often placed in a basement near an oven). The MERV rating tells you how efficient an air filter is at filtering particles of certain sizes.