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What Is A MERV Rating?

What Is A MERV Rating And What It Means To You

Every home contains pollutants that compromise indoor air quality. Unwanted dirt, dust, and microorganisms may be too small for the eye to see, but they significantly impact the quality of the air we breathe.

It is estimated that we spend nearly 70 percent of our day indoors. As such, we need to be mindful of the quality of the air that we have circulating through homes, office buildings, and even schools. An efficient HVAC system with quality filters can do wonders for improving the quality of the indoor air you and your family breathe.

Your HVAC Filter

Air filters are needed in HVAC systems in order to remove allergens and other harmful pollutants from the air that is circulating throughout your home. Filters become dirty and saturated over time; they need to be replaced at regular intervals to ensure that your indoor air stays fresh and clean. Dirty filters can continue to circulate the very same debris that was previously trapped when the filter was clean, resulting in a HVAC system that circulates dirty air through the rooms in your home.

Selecting The Right Filter For Your Home

Filter shopping can be frustrating if you don't know what to look for. Looking for a MERV rating that is in keeping with your needs and household demand will not only make your HVAC system more efficient, but it will give you the quality indoor air that you are looking to provide for your loved ones. Read on to see how MERV ratings are determined and what you should be looking for when you purchase air filters for your HVAC system.

How The MERV Rating Works

The MERV rating system ranges from a score of 1 to 20. MERV stands for Minimum Efficiency Reporting Values. In general, the higher the rating on an air filter, the more efficiently it can remove harmful particulates from the air that you breathe. Most homes only require a MERV rating of 8 or higher to yield high-quality results. Anything rated under a 5 would be insufficient in being able to provide clean, breathable air. On the other hand, MERV ratings that are too high can significantly impact the performance of a standard residential heating and cooling system.

How Ratings Are Determined

HVAC filters go through an extensive testing process to determine their MERV rating. Miniscule particles are sprayed a number of times through filters and then counted on the other side. The worst test score involving all test sessions results in the MERV rating. This is meant to be a standard measure of the minimum efficiency of a product.

What Do Various MERV Ratings Filter Out?

MERV ratings have a significant impact on what a filter is capable of trapping from indoor air. A good snapshot of filtration capabilities is as follows:

  • Rated 1-4: Pollen, dust mites, sanding and spray paint dust, textile, and carpet fibers
  • Rated 5-8: Mold spores, hairspray, fabric protectors, dusting chemicals, cement dust
  • Rated 9-12: Legionella, humidifier dust, lead dust
  • Rated 13-16: Bacteria, tobacco smoke
  • Rated 17-20: Viruses, carbon dust, combustion smoke

More explanation of filtration capabilities takes into account factors such as dust spot efficiency and arrestance. Dust spot efficiency refers to a filter's ability to remove atmospheric dust from the air, while arrestance indicates the ability of any filter to remove injected standard dust from test air. Arrestance is typically calculated as a percentage relationship according to weight.

The Connection Between MERV and Indoor Air Quality

Consequences of poor indoor air quality include:

  • Eye, nose, and throat irritation
  • Dizziness
  • Headaches
  • Fatigue
  • Allergies
  • Asthma and respiratory distress
  • Skin conditions
  • Nausea

As you can see, it would be easy for poor indoor air quality to significantly reduce your and your family's quality of life over time if not properly monitored and corrected. Changing or upgrading your filter will protect your home and your loved ones from the discomfort and damage that poor air quality will cause.

MERV Ratings and Energy Efficiency

Standard home HVAC systems generally need filters with MERV ratings ranging from 8 to 13 in order to optimize function and performance. Your system will have to push air through tiny holes in this filter, causing it to increase its energy usage to circulate air throughout your home effectively. One might think that it's a good idea to purchase a MERV rating of higher than 13, thinking that you're getting better air quality as a result. In actuality, you may be damaging your system. Most residential HVAC systems are only designed to handle a certain amount of forced filtration while maintaining optimal function. A rating of 8 and 13 is designed to work well with your existing system to provide good air quality without compromising your system or causing drastic changes to your energy consumption and bills.

How Your Filter Affects Your System

Most manufactured HVAC systems are built with recommended filters and MERV ratings in mind. Using a substandard filter or one that costs less could result in expensive repair and replacement problems for your unit. Filters that are inefficient in clearing out particulates will create a backlog of dust, dirt, and debris that circulates through mechanical components and ductwork, causing your system to work harder than it should. Your HVAC efficiency drops at the same time that energy prices skyrocket. Both situations will result in early system breakdown and expensive repairs that can be avoided.

What MERV Rating Filter Should You Buy?

The best course of action is to read your HVAC system owner's manual to find out what your recommended MERV filter rating should be for system optimization. The number of people and pets, along with any pre-existing health conditions, should be taken into account when choosing a filter in the range indicated in the owner manual for your home.

Having questions about choosing the right filter is understandable; a qualified HVAC technician will have the knowledge needed to provide you with expert advice on choosing the ideal filter for your system and for your family's health.

Change Filters Regularly For a Cleaner Home

A side benefit of maintaining your air filters is a cleaner home. A clean filter will catch dust and debris that would normally land on your furniture, carpets, and countertops. Making changing your filters a part of your routine can reduce the amount of time you need to spend vacuuming, washing, and dusting and will result in a cleaner household.

TR Miller: Expert Service, Every Time

TR Miller Heating, Cooling & Plumbing has qualified and caring HVAC professionals ready to serve all of your heating, cooling, and plumbing needs. Serving Plainfield and the surrounding areas for nearly three generations, we pride ourselves on providing the best service that ultimately yields your comfort and satisfaction. Our various services include drain cleaning, plumbing repair and replacement, heating and cooling installation and repair, and boiler service for both residential and commercial properties. Expect on-call service, cutting-edge technology, and no-nonsense pricing on all of our repair, maintenance, and installation services. We care about your comfort, and we're ready to serve you! Contact TR Miller Heating, Cooling & Plumbing today for more information on how we can improve the energy efficiency and comfort of your home in any season.