What is the Highest MERV Rating for Air Filters?

In general, a MERV rating between 6 and 13 is suitable for most homes. This range provides 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. The Minimum Efficiency Reporting Value (MERV) rating measures how well the filter prevents dust and other contaminants from entering the air stream.

MERV indices range from 1 to 16, with higher indices trapping small particles more effectively than lower indices. Each MERV classification was created for a different application; the highest filtration rates (MERV 13 to 20) are typically used in sterile environments such as hospitals or laboratories, as they need to filter bacteria, pathogens, and other microscopic contaminants. The Environmental Protection Agency (EPA) states that MERV 16 can remove up to 99.97% of particulate matter from the air. A higher MERV rating often means lower airflow, which can cause the system to work harder and consume more energy. It is important to select the right type of air filter to avoid putting extra pressure on the oven.

If you need a visual breakdown of MERV air filter ratings, check out these comparison tables. When used in a multi-filter system, prefilters trap dirt and large particles before the air reaches the final filters downstream, which remove the smallest particles. The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) recommends MERV 13; however, this may not be the most efficient option for some residential air conditioning systems. Researchers from India compiled a series of studies that analyzed the effect of air filtration on indoor air quality and the resulting positive health outcomes. Air filters with the highest MERV ratings are designed to trap the smallest particles and tend to be coarser.

The denser and denser the fibers of an air filter, the more difficult it will be to push air through them. These studies found that filtering recirculated air improved microvascular function in healthy older people, improved other types of vascular function in healthy adults, and improved lung function in indigenous communities, among other benefits. MERV 13 air filters cause a slight strain on the operation of the air conditioning system since less air can pass through. It is important to select an appropriate filter for your home or business in order to ensure optimal performance and energy efficiency.