Ever noticed the MERV rating on air filters and wondered what it meant? Read on to learn more about MERV ratings and which filter rating you should be using for your home or business.

What Does MERV Rating Mean?

MERV stands for Minimum Efficiency Reporting Value and is a system used to evaluate the efficiency of an air filter based on how effective it is at catching particles of varying sizes. This system was developed in the 1980s by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE).

Essentially, the higher the rating, the more efficient a filter will be at removing particles from the air passing through it. Some of the highest-rating filters can stop particles as small as 0.3 microns from getting into the air. This is all to say the right air filter can be a game-changer for your indoor air quality, but most people don’t think about the filter rating they use.

MERV Rating Scale

So, how does the rating scale work? The MERV ratings range from 1 to 20, with 1 being the lowest level of filtration and 20 being the highest. Let’s go over the ratings and what they mean:

  • MERV 1-4 – these filters are commonly used for industrial workplaces and pre-filtering commercial buildings. They can remove pollen, dust mites, sawdust, textile fibers, and cockroach debris. While they do filter out particles, these filters are not recommended for home use.
  • MERV 5-8 – filters in this range are typically used for commercial and residential buildings. They can filter out pollen, dust mites, textile fibers, mold spores, household dust and lint, and concrete dust.
  • MERV 9-12 – hospital labs are where you’ll most likely find these air filters, but they can also be used in residential homes for those who need above-average air quality. These filters will capture additional particles, including coal/lead dust, pet dander, legionella, and humidifier dust.
  • MERV 13-16 – these are commonly used for spaces that require superb air filtration, such as general surgery facilities, inpatient care hospitals, etc. These will filter out all the previously listed contaminants, as well as sneeze particles, fumes, cosmetic dust, and smoke.
  • MERV 17-20 – the highest-rated filters are used in orthopedic surgery rooms, pharmaceutical manufacturing facilities, and carcinogenic housing buildings. They remove everything previously listed, as well as virus carriers, carbon dust, sea salt, combustion smoke, and microscopic allergens.
What is a Good Rating?

So now that you know what a MERV rating is, you probably want to know what the “good” or “best” rating is. But just because a filter has a higher rating does not mean that it is necessarily right for your home or needs. There are a few factors that should be considered when it comes to determining a “good” MERV rating for each individual home and business.

What You Should Consider

For one, you should take into consideration the needs of your family and/or employees. If there are people in the home or business that suffer from allergies, asthma, or some other raspatory ailment, a filter with a higher rating might be necessary. Shedding pets may also mean you need an air filter with a higher rating.

You should also consider the power of your HVAC system. An air conditioner or furnace filter with a MERV rating on the higher end has more resistance, so it needs a powerful HVAC fan to successfully push air through that filter. This is because air filters with higher ratings are typically created with more compact filtration materials to catch the smallest particles. If you choose a filter with a rating too high for your HVAC unit, you could end up impairing the system’s performance and potentially lead to the need for frequent repairs or maintenance.

Last but not least, your location can also make all the difference in choosing a filter rating. A home in a suburb won’t need the same air filter rating as a downtown apartment overlooking busy streets. That’s because a populated city produces higher levels of air pollution than the outskirts, where homes are more spread out. A home in the suburbs probably won’t need an air filter higher than a MERV 8 (depending on pets and allergies). For homes more central to the city, a higher rating, like MERV 13, will help to filter out the increased levels of pollutants,

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Find the Filter Rating that’s Best for You

Choosing the right air filter for your space promotes a healthy, clean living environment. But with so many variables, how do you know which MERV rating is right for you, your loved ones, your home, and your HVAC unit?

If you need help deciding which air filter is right for you, Comfort World Air Conditioning & Heating is here to help you. Our professional team can also provide HVAC maintenance, repair, and AC installation services. We’ve been bringing comfort to the valley for over 30 years, so you can count on us to get the job done right. Our highly trained technicians in Scottsdale, Arizona, want to bring a little more comfort to your world!