Improving your indoor air is especially important. But how can you do that? How can you remove or at least reduce the sources of air pollutants, viruses, and germs? 

This is where air filters come in. But the thing is, some air filters work great while others are not so efficient. For this reason, it is also essential that you look into the ratings. We will be focusing primarily on MERV vs HEPA air filters to get a better understanding of your air filter needs.

If you have been looking up air filters and their ratings, you probably have come across MERV and HEPA. What are they? What are the differences? In this post, we will focus on MERV vs HEPA air filters to better understand your air filter needs.

MERV, HEPA, and Coronavirus

It has been shown through research that adding filtration to your ventilation system can produce positive results. Since the coronavirus outbreak, more and more people have started looking for better ways to protect themselves, including the airborne transmission of viruses. Therefore, various products have been introduced, each claiming to be the best in making a residence or a business establishment healthier and safer. 

who says coronavirus can be airborne image merv vs hepa air filtersIt is believed that the coronavirus is usually spread when an infected person coughs or sneezes. If you get in contact with respiratory secretions, you will most likely get infected. However, that is not the only way in which you can get the virus. The World Health Organization (WHO) said that airborne transmission is also very much possible. 

This is when tiny droplets from an infected individual’s respiratory secretions get suspended and stay in the air for quite some time. ASHRAE has then come up with an excellent way to help prevent the airborne transmission of the coronavirus. One of them is air filters, not just any air filter but with superior ratings!

MERV and HEPA are air filter ratings systems. But what is the difference between MERV and HEPA ratings? Read on as this article will describe MERV vs HEPA air filter ratings. 

What is MERV?

What does MERV stand for? MERV or Minimum Efficiency Reporting Value is a scale used to measure an air filter’s efficiency as determined by ASHRAE. The rating is from 1 to 16. The higher the rating is, the more efficient an air filter is at capturing small particles suspended in the air. In short, you must aim to get something that has high ratings. 

Here is a summary of the different MERV ratings:


  • 1-4 = Average arrestance: 60-80% / Particle Size Range: >10 microns / Applications: Small homes and establishments
  • 5-8 = Average arrestance: 80-95% / Particle Size Range: 3 to 10 microns / Applications: Industrial work environment and commercial buildings
  • 9-12 = Average arrestance: 90-98% / Particle Size Range: 1 – 3 microns / Applications: Huge residential buildings, industrial workplaces, and commercial buildings
  • 13-16 = Average arrestance: 95-99% / Particle Size Range:0.3-1.0 microns / Applications: Hospital in-patient care, and superior commercial buildings.
How is a MERV Rating Determined?

The MERV rating for air filters is determined through laboratory tests that utilize an aerosol generator as well as synthetic dust. Take note, though, that a filter can only be effective when there is the movement of air. That is why increasing the operating schedules of ventilations, 24 hours 7 days a week if possible, is highly recommended. More foreign articles will then be captured as the air moves through the filter.

A MERV 13 or higher-rated filter is recommended, but how would you know if the MERV filter will satisfy your needs? A MERV 13 filter can trap about 75 percent of air particles that are 0.3 to 1 micron in size at its minimum efficiency. The bigger the air particle is, the more efficient this group of filters becomes. Are they the best?

lab testing forced air image in merv vs hepa air filter test
How do HEPA Filters Compare to MERV?

A HEPA (high efficiency particulate air)  filter generally is equal to  a rating of MERV 17. It can trap 99.97% of air particles of .3 to 1 micron in size. As for air particles 3 to 10 microns in size, 99 percent can be trapped.

HEPA filters are very efficient. So why doesn’t everyone simply use HEPA filters and forget the rest. Well, like anything, people have to weigh the pros and cons along with the cost and convenience to make a choice. And there then becomes a market full of a wide range of air filters.

Should everyone use HEPA filters?
merv vs hepa air filter closeup view of particles on filter

With HEPA filters, one needs to consider that they are not universal. This means that systems may need replacement or significant upgrading to work with HEPA air filters. Some companies provide add on units designed to use HEPA with your existing air handers, but these are also quite expensive.

In addition, because of the size particles and gas molecules being trapped in the filter, these filters present much more resistance to air flow. That means that the blower on your HVAC unit has to work much harder to push the air through. And if you are serious enough about your air (like perhaps a hospital might be) to use this kind of filter, then you are probably running your blower 24/7, or at least more often than normal.

A blower working harder and more often means using significantly more energy. This in turn means significantly higher cost to you. And then one needs to ask if the HVAC units will last as long if they are working harder and longer. It is likely that it will need to be replaced more often also – which is a considerable expense.

The good news is that these filters are available for use with portable air cleaners. COVID-19 can be easily spread, and the right filter helping to circulate air can significantly help reduce the risks. These infection droplets typically range around 5 microns in size and are thus much easier to catch by a HEPA. This group can filter super tiny particles in the air.

Here are the different classes of HEPA filters as used in the European Union: 


  • E10 – Retention (average): 85% Retention (spot): –
  • E11 – 95% / –
  • E12 – 99.9% / –
  • H13 – 99.95% / 99.75%
  • H14 – 99.995% / 99.975%
  • U15 – 99.9996% / 99.9975%
  • U16 – 99.99995% / 99.99975%
  • U17 – 99.999995% / 99.9999%
MERV vs. HEPA Air Filters – Which is Recommended?

The answer needs to come from consideration of all aspects and conditions. HEPA filters have been proven to be highly effective air filters. But at what cost? Thus, consider your uses in places like isolation or quarantine facilities, wards, and patients’ rooms. Or do you have a typical business and/or home?

Final Thoughts on Air Filters

Be it for residential or commercial use MERV 13 air filters are very efficient but not the same as HEPA filters. Whatever filter you use, though, you must consider your ventilation system’s capacity.

If your ventilation system is not designed for a high-efficiency filter like HEPA, you might as well use a portable air cleaner with the highest possible efficiency rating. Or another option is to upgrade the ventilation system itself, but that could be very expensive.

Now you should have a better idea of MERV vs HEPA air filters and can now make an informed decision on which one is right for your home or commercial building. Of course, choosing a highly trained professional to help guide you is also a plus. So reach out to NanoAir Solutions trained professionals.

merv vs hepa air filters showing merv 13 filter from nanoair solutions

NanoAir Solutions believes in MERV 13 rated filters as the best choice. In addition, NanoAir filters have additional features that make them more desirable that the average reseller filters. Check out our filter selections of 1 in., 2 in., and 4 in., in a huge variety of sizes. If you need help or even need custom sizes give us a call at 844-NAN-0-AIR [(844) 626-0247] or reach us at