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What is a MERV rating?  What does MERV stand for?  Why is it important to understand MERV ratings?

What is a MERV rating? What does MERV stand for? Why is it important to understand MERV ratings?

Posted by Caty on Nov 19th 2019

MERV ratings - you see them associated with air filters all the time, no matter where you shop. But what is a MERV rating? What does MERV stand for? Why is it important to understand MERV ratings? We’re here to answer those questions.

MERV stands for Minimum Efficiency Reporting Value, a measurement scale designed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to rate the effectiveness of air filters. This scale allows for improved health, reduced cost and energy efficiency in heating, ventilation and air conditioning design. In fact, according to the Environmental Protection Agency, medium-efficiency filters of MERV 7 to 13 are nearly as effective as true HEPA filters at removing allergens. MERV rated filters are much more practical in central HVAC systems, and are also associated with much lower system and operating costs.

The MERV rating scale is designed to represent the worst-case performance of a filter when dealing with particles ranging in size from 0.3 to 10 micrometers. What is worst case performance? In simple terms, it refers to the filter’s performance in testing. Tests are completed at each particle size, measuring particles in the air before and after it is filtered. The worst result for each particle, meaning the result with the lowest percentage of particles filtered, is used in determining the MERV rating.

MERV Ratings can be as low as 1, and as high as 16. You may see MERV ratings as high as 20, but those ratings are not part of the official standard specification. You would mostly find MERV 16 filters in hospitals and manufacturing clean rooms, rather than standard households and businesses. Filters with a MERV Rating of 1-4 typically remove less than 20% of the largest particles (sized from 3 to 10 micrometers). Because of this poor performance, you won’t see those ratings available anywhere in our online shop. In fact, we only sell filters with a MERV rating of 8 or higher, and so we’ll focus on those ratings for the remainder of this article. But before we continue, let’s review two of the questions we’ve answered so far:

What is MERV and what does it stand for?

MERV, or Minimum Efficiency Reporting Value, is a measurement scale used to rate the effectiveness of air filters. The rating assigned to each filter determines what is effectively filtered out of the air in its use. This brings us to the answer to our final question - why is understanding MERV ratings important?

Understanding MERV ratings allows you to make the best decisions about air quality in your home. Understanding what your filter is removing from the air can promote the health of all of your home’s inhabitants, and knowing whether you need a MERV 13 or can probably get by with a MERV 8 can help save on costs. So let’s take a look at what each MERV rating filter available at our online store actually filters from the air.

MERV 8 Filters: These filter out the basics, like lint, household dust, dust mites, pollen and mold spores. If you are a pet free household with generally healthy inhabitants, filters with a MERV 8 rating will generally suffice.

MERV 11 Filters: These filters catch all the things a MERV 8 filter does, plus pet dander, smoke, smog and other things that might make you cough or sneeze. These filters are recommended for pet owners, smokers, anyone who has mild allergies, and those who are looking for a bit more filtration.

MERV 13 Filters: As before, these filters catch all the things both a MERV 8 and MERV 11 filter will catch. They also give added protection by filtering bacteria and virus carriers. These filters are great for anyone with multiple pets, or severe allergies. They are also helpful in more densely populated areas, especially those with poor air quality.

So, to summarize! MERV, or Minimum Efficiency Reporting Value, is a measurement scale used to rate the effectiveness of air filters. The rating assigned to each filter determines what is effectively filtered out of the air in its use. Understanding MERV ratings allows you to make the best decisions about air quality in your home. Whether you just need a basic MERV 8, a step up MERV 11 for your pets and mild allergies, or a strong MERV 13 for your multiple pets or severe allergies, knowing which works best for you makes shopping all the easier? Why stop there? Add another layer of convenience with our filter subscription service! Check out our online store today, and take control of the air quality in your home, without ever leaving it!