Overall, a MERV rating between 6 and 13 is the ideal choice for most residences. This range offers a good balance between air filtration, airflow and affordability. An air filter with a MERV 13 rating can last up to six months before needing to be replaced. MERV stands for Minimum Efficiency Reporting Value and indicates a score of 1 to 16 for residential air filters sold in the United States and 17 to 20 for commercial air filters.
The scale shows how well a filter removes fine particles from the incoming air. The higher the MERV rating, the more particles the filter removes. Generally, it is recommended that most homes and commercial spaces have a filter with a MERV rating of at least 5 and 12 in the high-end. For those with respiratory problems, a specialist might recommend a different filter.
Hospitals use air filters with a MERV rating of 13 to 16. A MERV 8 is considered to be superior filtration compared to air filters with a lower MERV rating. But is filtration enough? In many cases, a MERV 8 air filter is more than adequate. If you're concerned about outdoor air pollution, family members with respiratory problems, or the presence of pets at home, then opting for a higher MERV rating might be a good idea. A MERV rating of 13 to 16 is considered to be hospital-grade air quality, so it's unlikely that your home will need more than that rating.
According to the United States Environmental Protection Agency, filters in the 7-13 range usually have little difference from the highest MERV ratings, but they will allow the system to operate much more efficiently. Air filters used in hospitals and homes generally have a MERV rating of 9 to 12. Just make sure your HVAC system is compatible. Some air conditioning systems cannot withstand a high rating, which could interrupt air movement. While the highest MERV ratings are the most effective for air quality, they can damage your HVAC system.
MERV ratings are determined through tests performed by the American Society of Heating, Refrigerating and Air Conditioning Engineers. These ratings are appropriate for buildings that are only looking to filter out dust particles or a low level of airborne particles. Generally speaking, everything underneath a MERV 13 air filter should provide very efficient air purification in a home without affecting airflow. A MERV rating of 5 to 8 effectively captures pollen and other particles ranging in size from 3.0 to 10.0 microns.
MERV 11 air filters are slightly more expensive than standard filters, but it's usually worth paying extra for their added efficiency. In 1987, the American Society of Heating, Refrigerating and Air Conditioning Engineers designed the MERV rating scale to provide an accurate picture of an air filter's capabilities. It can reduce the effectiveness of your heating, ventilation and air conditioning system and lower the air quality in your home or building. MERV 8 air filters are almost as affordable as less efficient products, making them good value for money.
It's also worth noting that a higher MERV rating isn't always better, especially in homes. Choosing the right MERV rating is an important decision in terms of total cost, air quality and product durability.