The Importance of MERV Ratings

How Air Filters Work and MERV RatingsWhile we are still in the midst of the Covid-19 pandemic, it seemed to be a good time to revisit the importance of MERV ratings when it comes to the filtration in your home. MERV stands for Minimum Efficiency Reporting Value. The ASHRAE (the American Society of Heating, Refrigeration, and Air Conditioning) developed the MERV system in 1987 as a scale used to measure the effectiveness of air filters. The MERV ratings system makes it easier for consumers to compare the effectiveness of all the different air filters available.  The material used, quality and construction of air filters may differ; however, the MERV system sets expectations for the level of filtration provided from an air filter with a specific MERV rating. In simpler terms, this means that any MERV 8 rated air filter will have the same level of filtration another filter with a MERV 8 rating, no matter the material, quality, or construction.

Ranging from 1-16, MERV ratings score the performance level of a filter related to the removal of airborne particles from 0.3-10 microns in size. Microns are used as the measurement for airborne particles and a micron is 1/1000th mm…equal to 1/25,000ths of an inch. The human eye can see particles beginning around 20 microns but in the right conditions, it is sometimes possible to see particles as small as 10 microns. To put that into perspective, a dot (.) is just about 600 microns.

Comparing MERV Ratings

The table below shows a low-level comparison of MERV ratings. Check out our MERV Rating Comparison chart for a more in depth look at the differences.

System Protection Level Dust Control Level Allergy Concern Level
MERV 8 Good Good Mild
MERV 11 Better Better Moderate
MERV 13 Best Best Severe

MERV Ratings and COVID-19

What filter is best to protect your home from COVID-19?  The National Air Filtration Association reports that there is no straight forward answer to this question due to all the unknowns regarding the nature of SARS-CoV-19 containing particles and droplets.  What is known is that low-efficiency filters (less than MERV 8) are highly unlikely to make a difference.  Properly installed higher efficiency filters can remove particles of a relevant size depending on their installed capture efficiency, but current information does not allow for specific recommendations.

Buying Filters with High MERV Ratings

Logic would make it seem that you would want to buy a filter with the highest MERV rating possible, right? Oddly, that is not necessarily the case.

You now know that air filters with high MERV ratings means the filter is highly effective in preventing harmful airborne particles from circulating throughout your home. However, a high MERV rating filter could also be overly effective which, in turn, can prevent the air itself from being to circulate. This is a bad thing and the result may be poorer air quality in your home. Also, if the air is unable to circulate due to more resistance, your HVAC is doing more work than it should be. The result is an inefficient HVAC system, high energy bills, and it can even lead to costly repairs in the long run.

What MERV Rating Should I Buy?

This really all depends upon your individual HVAC system, but for a typical home the ideal MERV rating would be between 8 and 13. As far as protection from the coronavirus, you’d definitely want stay away from MERV ratings under 8. The most important thing when choosing an air filter, regardless of MERV rating, is that is compatible with your HVAC system. You may think that selecting high MERV rating filters will remove more of the harmful particles from your home, but too high of a MERV rating could actually reduce the air quality of the air you breathe in your home. Filters with higher MERV ratings also must be changed more frequently than those with a lower MERV rating.

Filters with MERV ratings higher than 16 are available, however, they are thicker and denser, and your typical residential HVAC system cannot readily handle them. And, as stated before, they can actually interfere with the airflow by restricting it. This in turn can reduce the effectiveness of your heating and cooling systems and can even result in damage to the HVAC equipment. You should consult with an HVAC professional to make sure that your HVAC system can handle filters with MERV ratings higher than 16 before buying and installing one.

If you still want the filtration of a MERV 16 but your HVAC system can’t handle it, there are additional units that can be installed along with your HVAC system that are designed for air filtration and purification. These air cleaners can provide an additional step “on top” of the regular filtering, thus cleaning your air even further.

US Home Filter Carries AC Filters to Fit All HVAC Units

No matter which HVAC system you have, every unit needs a quality filter that fits properly in order to keep your indoor air quality clean, your unit running at its maximum efficiency, and your energy costs down. US Home Filter can supply you with the best and most efficient HVAC filter available! US Home Filter makes filters that fit all AC/HVAC units. From standard to custom air filters, to whole-house filters, grille filters and humidifier filters, we have all of your filter needs covered!

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Selecting the filters that are just right for your home can be difficult and confusing at times. At US Home Filter we understand this, which is why we offer an experienced staff to help answer any questions you may have. For personal assistance with your air filter needs, please contact us now online or call us at (855) 237-1673 and we will do our very best to assist you in selecting the right filter for your individual needs. We want to earn your business and we guarantee your satisfaction! Take advantage of our quality products, vast selection, low prices, and enjoy FREE SHIPPING on every air filter order within the Contiguous USA.