What Is a MERV Rating, and Which One Should You Choose?

The MERV rating was originally designed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) to rate air filters by effectiveness. It is an abbreviation for Minimum Efficiency Reporting Value, which is calculated by comparing a filter’s efficiency to the particle size it can capture. 

On a scale of 1 to 20, the higher the MERV rating, the more efficient a filter will be at capturing airborne particles such as dust, pollen, and mold. It’s crucial to understand what MERV ratings mean so that you can select the proper filter for your building. 

Though filters with a higher MERV rating are more efficient at capturing airborne particles and contaminants, a filter within MERV 7 to MERV 13 is actually good enough to maintain healthy air quality in commercial and residential buildings. However, in environments such as the hospital or in homes of people with respiratory conditions, using filters with ratings higher than MERV 13 is more beneficial to the residents.

However, it is important to note that the filter with the highest MERV rating doesn’t always mean it’s the best option for a home. To efficiently filter out tiny airborne particles, a filter with a high MERV rating tends to have smaller pores in order to prevent particles from passing through. As a result, there is more resistance in airflow and an increase in pressure on the fan of an AC system or furnace. 

Before choosing an HVAC filter that is most suitable for you, it is worth doing some research and figuring out what MERV-rated air filters are most efficient at bettering air quality while maintaining sufficient airflow. 
 

While MERV 13 and MERV 14 are currently recommended by the ASHRAE, you should also take into consideration the capabilities of your HVAC system. If a filter with a MERV rating of 13 or higher could not be accommodated in the system without causing increased resistance, it is best to use the highest MERV rating possible that wouldn’t compromise the HVAC system’s functionality. 

MERV 1-4

These filters have little impact on airflow, which allows air to circulate without much resistance. However, since the filters are extremely porous and ineffective at filtering, air quality is often compromised as a result. 

• Filters down to 10 micron particle size.
• Controls contaminants such as pollen, dust mites, and carpet fibers.
• Commonly used in window air conditioning units and residential furnaces.

MERV 5-8

Filters with MERV ratings between 5 and 8 are often considered medium-quality, which is sufficient for most homes. However, they need to be replaced more frequently than high-quality filters. 

• Filters down to 3 - 10 micron particle size.
• Controls contaminants such as mold, dust lint, cement dust, and textile fibers.
• Commonly used in commercial buildings, industrial workplaces, and paint booth inlets. 

MERV 9-12

These filters are effective when it comes to removing particles from indoor air that are hazardous to your health, which makes them great options for residents who have allergies and other respiratory conditions. 

• Filters down to 1 - 3 micron particle size.
• Controls contaminants such as humidifier dust, Legionella, and nebulizer dust.
• Commonly used in hospital laboratories, or as pre-filters or final filters. 

MERV 12-16

Filters with MERV ratings between 12 and 16 provide highly efficient and effective residential air filtration. They are especially suitable for people who live with pets who often need more help maintaining indoor air quality. 

• Filters down to 0.3 - 1 micron particle size.
• Controls contaminants such as auto fumes, sneeze nuclei, and insecticide dust particles.
• Commonly used in hospital inpatient care areas, general surgery rooms, and smoking lounges. 

MERV 16-20

These high-quality filters are designed to capture extremely tiny particles that can pose a threat to the human body. They are often used in commercial HVAC systems in industrial facilities, manufacturing plants, or hospitals. 

• Filters down to smaller than 0.3 micron particle size. 
• Controls contaminants such as virus carriers, carbon dust, and microscopic allergens. 
• Commonly used in pharmaceutical manufacturing facilities, orthopedic surgery rooms, and environments with radioactive materials. 
   

MERV, MPR, and FPR rating systems differ in range and are developed by different organizations. MPR, which stands for Microparticle Performance Rating, was originally created by 3M and measures ratings based on particle sizes between 0.3 and 1 micron. Whereas FPR, which is an abbreviation of Filter Performance Rating, was designed by The Home Depot and rates filters on a scale of 4 to 10. 

Currently, MERV Rating is the primary rating system being used in the industry domestically and internationally. However, despite some differences, these systems all show a filter’s ability to capture particulate matter in the air. In addition, it doesn’t matter which rating system you choose, it is still important to install replacements frequently and dispose of old filters on a regular basis.

Choosing the most suitable MERV-rated filter for your HVAC system not only ensures better air quality, but also helps reduce unnecessary energy consumption while saving on electricity costs. Ready to improve the air quality in a residential or commercial building? Head over to Zoro to check out all the air filters you might need. 

Sources: ASHRAE

 

 

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.