What Is the Difference Between MERV 13 and HEPA?

Good air quality has always been important but is even more so today as COVID-19 and its mutations continue to affect the nation, flu season is upon us, and "sick building syndrome" threatens health and safety. It is now critical that gathering spaces, such as businesses, organizations, and schools, maintain a higher level of air quality to prevent the spread of bacteria and viruses and keep people safe and healthy. 

When adding or making improvements to your existing air purifiers, you need to understand the various technologies to determine what is available, what will work, and what will fall short. One of the primary issues to address is filtration and the difference between MERV 13 and HEPA filters.

Not all filters are the same. Each has its own sets of pros and cons, which ultimately make a difference in which you choose. Learning more about both filters and understanding their differences will help you make a well-informed decision to determine the best-suited solution for your business.

What Is A HEPA Filter?

HEPA, or high-efficiency particulate air, is a pleated mechanical air filter that traps particles and cleans the air. A HEPA filter is a mechanical filter that effectively removes 99% of particulate matter (PM) when air passes through it. It is typically made with borosilicate glass fibers, plastic fibers, or fiberglass.

HEPA is an air quality cleanliness measurement defined by the US Environmental Protection Agency (EPA). You can also purchase True HEPA or Absolute HEPA: While most filters are labeled "HEPA," only True HEPA and Absolute HEPA, which ensure air filtration efficiency at a higher level, are individually evaluated and verified. 

HEPA is a popular choice because it can capture particles as small as 0.3 micrometers in size, considered one of the most penetrating particle sizes (MPPS). MPPS can range from 0.3 to 10 micrometers. 

Most heating, ventilation, and air conditioning (HVAC) systems have a HEPA filter at one end of the air duct. The HVAC system circulates air; larger particles, like hair, dander, moisture, dust, and pollen, are filtered out as air moves through the HEPA filter. 

However, a HEPA cannot capture contaminants that are not particulate matter, such as volatile organic compounds (VOCs). While a HEPA filter attached to your ventilation system will help improve air quality, you will not get the best results with a HEPA filter alone. 

What Is The MERV Rating System? And What Is MERV 13?

A Minimum Efficiency Reporting Value (MERV) is another rating of how effective a filter is in stopping particles, dust, and contaminants based on a percentage of the time. [GS2] 

The MERV scale, which runs from 1–20, was developed by leading air quality experts at the American Society of Heating Refrigerating and Air Conditioning Engineers (ASHRAE)  and is a useful way to compare the performance between different filters. In general, the higher the MERV rating, the more effective the filter is in stopping smaller particles. 

However, higher is not always better; it depends on your HVAC system and its requirements. For instance, higher-rated MERV filters may have smaller pores that can cause airflow restrictions that lower your HVAC system's efficiency. Additionally, some HVAC systems are outdated and simply cannot handle MERV 13 filters.

For commercial buildings, MERV 13 is recommended by the EPA to ensure clean air and proper filtration. MERV 13 can capture smaller particles, including dust, pollen, mold, bacteria, and viruses. They have become increasingly popular since the start of the COVID pandemic because they can capture SARS-CoV-2 particles. The SARS-CoV-2 particle is only 0.1 micrometer in size, but it latches on to the larger particles (0.3 micrometers) caught by the MERV 13 filter. 

Adding an activated carbon pre-filter to a MERV or HEPA filter can help remove contaminants such as VOCs, odors, smoke, formaldehyde, and gaseous fumes.

FPR And MPR Filter Rating Systems

When addressing air quality technology and HVAC filters, facilities managers often encounter these rating systems. Read on to learn the difference between the FPR and MPR rating systems.

What Is The Filter Performance Rating?

The Filter Performance Rating (FPR) refers to a rating scale developed by The Home Depot to measure the air quality efficiency of the brands sold in its stores. The FPR rating scale ranges from 4 to 10 rate effectiveness and is color-coded to signify Good (4–5), Better (6–7), Best (8–9), and Premium (10). 

FPR is specific to The Home Depot. While it is like MERV 13, it has a wider range when ranking filters: FPR goes from 4–10, while MERV runs from 1–20. FPR 10 strength is comparable to MERV 20, as it is the highest level of filtration. However, MERV 1 doesn't correspond to FPR 1. FPR rating 4–5 traps larger particles like household dust and lint, dust mites, pollen, and pet dander. That level of filtration is achieved by MERV 1–4.

Additionally, MERV rates a filter's ability to trap microscopic and macroscopic particles; FPR ratings only look at the filter's ability to capture or remove particles from 0.3 to 1 micron. For reference, a typical dust particle is usually sized between 0.2 and 0.8 microns. Pollen is around 7 microns and can get up to 70 microns.

What Is The Micro-particle Performance Rating System?

The Micro-particle Performance Rating (MPR) is a rating system developed by 3M that applies only to 3M filters. Like Home Depot's FPR system, the MPR rates filters based on the ability to capture tiny particles between 0.3 and 1 micron in size. 

MPR ranges from 600 to 2800 and is divided into Good (600), Better (800–1200D), and Best (1500–2800). Like MERV, the higher the MPR, the more microparticles the filter will capture. 3M is a large industrial brand, so it is fitting that they would have a proprietary rating system to help consumers understand the effectiveness of the filter they are purchasing in the context of 3M products. 

While the rating scales cannot be directly compared, each measures air filter effectiveness from least to most. Also, FPR and MPR ratings cannot be applied to other filters because they are used only by The Home Depot and 3M. 

What Is The Difference Between HEPA vs. MERV 13?

HEPA and MERV 13 are two very different rating systems. The MERV 13 rating system is continually assessed and monitored by ASHRAE, and filters that claim to be rated based on MERV can be tested for their effectiveness. 

HEPA is an air efficiency indicator based on a test method developed by the Department of Defense around the time of the development of the atomic bomb. The military and other high-cleanliness areas still follow HEPA standards (through the Department of Defense test method). 

Which is Best for My Business—HEPA or MERV 13?

The answer is both. While different filters efficiently filter out different substances, you do not have to compromise by using only one for air filtration in your office, school, or business. Instead, you can use multiple filters in one portable air purifier and get the benefit of all of them.

For starters, make sure that your HVAC has a HEPA filter, and it is either True HEPA or Absolute HEPA. Depending on the setting, the age of your system, and the space's size, you could also consider additional upgrades, such as HVAC induct ActivePure technologies. 

Your HVAC system should also have a MERV 13 filter. You can also get MERV 13 filters in portable filtration systems to support an HVAC with HEPA filtration. 

How To Incorporate Air Quality Controls in My Facility

Whether you are implementing air quality controls for a 2,000 or a 50,000 square foot facility Sanalife has the right solution. Let our team of experts work with you to determine the optimal combination of portable air purifier systems and HVAC Induct solutions. Sanalife's air purifier solutions combine multiple stages of filtration with active coverage to ensure optimal protection against airborne pathogens and contaminants. In addition, the range of models and equipment available ensure there is a system that best meets your specific needs. With a wide range of other portable filtration technologies, you have many choices and unlimited possibilities for cleaner air!