Good indoor air quality is important to help you feel comfortable at home. Airflow and airborne particles both impact air quality, and both these things are impacted by the air filter used in your HVAC system. While replacing it every few months is important, so too is the type of air filter you choose. The easiest way to compare different air filters is through the MERV rating system.

By comparing the different MERV ratings, you’ll have a much better idea of what type of filter is right for you. A trusted service company like Lakeside Heating & Air Conditioning can provide suggestions if they offer indoor air quality services. Indoor air quality experts can help you avoid picking an air filter that’s more than what you need for your home.

What Is a MERV Rating?

Designed by the American Society of Heating, Refrigerating and Air Conditioning Engineers (or ASHRAE), MERV stands for Minimum Efficiency Reporting Value. These ratings measure a specific filter’s ability to capture airborne particles like dust, pollen and mold spores. The rating system was developed partly because the contaminants are too small for traditional units of measurement like millimeters. The MERV system instead uses microns. The higher the MERV rating, the smaller micron size a given filter is capable of trapping.

What MERV Rating Is Best?

Modern designs for air filters have led to serious improvements in their overall effectiveness at capturing microscopic pollutants. In fact, some ratings are so high that they’re reserved for specialized facilities, like hospitals or for pharmaceutical manufacturing. Residential filters’ MERV ratings typically max out at 16. ASHRAE as well as the US Department of Energy generally recommend filters with a MERV rating of 13 or above, particularly if someone in your household has allergies or respiratory problems.

That being said, you don’t necessarily need to track down a filter with the highest available MERV rating. A higher capacity for trapping contaminants can also affect airflow, which in turn impacts your HVAC system’s energy efficiency.

What MERV Rating Do I Need?

The ideal MERV rating for your home’s air filter depends on a number of factors, like your local climate and the size of your family or home. An easy way to identify a quality air filter is to look for a HEPA filter. High Efficiency Particulate Air filters are rated to capture up to 99%+ of airborne particles, including viruses and bacteria below .3 microns in size.

Additionally, many effective air filters are included in dedicated air filtration systems, which can be integrated into the rest of your HVAC system. This equipment often combines different air purification technology like UV germicidal light, which is particularly useful for deactivating microorganisms like mold and mildew spores.

Comparing Some of the Most Popular MERV Ratings for Air Filters

MERV RatingHow Much Do These Filters Cost?What Contaminants Can It Trap?Where Are These Filters Used?Type of Filter
1-4$Pollen, dust, cloth and carpet fibersResidential, window AC unitsDisposable Electrostatic
5-8$$Mold and mildew spores, animal dander, Volatile Organic Compounds (VOCs)Residential, commercial, industrialPleated Filters Cartridge Filters Electrostatic
9-12$$$Some bacteria and emission particlesSuperior residential and commercial, hospital labsPleated Filters Cartridge Filters
13-16$$$Bacteria, smoke particlesGeneral surgery or inpatient careBag Filters

Box Filters


(Generally unavailable for residential use)

Viruses, bacteria, smoke particlesClean rooms, storage for radioactive and carcinogenic materialsHEPA Filters Specialized Filters