Air filters in an aisle at hardware store

What Air Filter MERV Ratings Mean for Your Home’s Air Quality

Air filters in an aisle at hardware store

Air quality plays a major factor in the overall health of our families. Conditions like asthma and allergies are impacted by the air we breathe, as a variety of pollutants can circulate in enclosed indoor air. We expect a certain level of comfort in our own homes, including breathing easily. 

Indoor air filtration is the key to air quality. But there are many factors to consider when it comes to air filters, how they eliminate pollutants and which one is right for your HVAC system. When staring at an aisle full of different air filters, which one should you choose?

MTB Mechanical New Construction Accounts Manager Charlie Cooper recently spoke with Ray Terry of About Your House Radio about air filters and the MERV rating system. Charlie says over the past year, many MTB customers are asking more questions about air filtration and quality. Here are three things we learned from their conversation: 


1. All Filters Have a MERV Rating

When shopping for an air filter, you may have seen each filter’s advertised MERV rating. But what does that really mean? MERV ratings, or Minimum Efficiency Reporting Values, indicate the particle size that a filter will remove from your air. 

A filter’s job is to trap pollutants and prevent them from passing through and into your home. The MERV rating lets you know what the filter can successfully trap when air moves through. MERV ratings are calculated on a scale of one through 16. The higher the rating,the more successful a filter is at catching the smallest particles. 


2. Pollutants Are Measured By Microns

Some things that pollute our air are easy to see, like dog hair. Others are too small to see with the naked eye, like bacteria. The size of these pollutants are measured by microns, with one micron being the equivalent of .001 millimeter, or one-thousandth of a millimeter. 

The MERV rating system tells you, down to the micron, what your filter is able to trap. A filter with a MERV rating of eight may eliminate things like pollen, pet dander and general household dust, while a filter with a 16 rating can eliminate the finest of particles, like those emitted through cooking and tobacco smoke. The Lennox® Healthy Climate® Carbon Clean 16® Media Air Cleaner captures particulate matter down to 0.3 microns. That’s over 95% of air particles. Right now, when you take advantage of MTB’s spring specials, you can save $50 on this Lennox® Media Air Cleaner.  


3. Not Every Filter Is Right for Every Home

It’s not as easy as putting the top-rated filter in your system and calling it a day. Filters restrict airflow, so in an older system, for example, a filter with a mid-level MERV rating is actually best suited. An HVAC professional, like an MTB technician, can assess your system’s specific needs and make a recommendation.

Kids, pets and traffic in and out of your home impact the level of filtration required, so filter needs can change even between floors in your home. A filter may advertise needing to be changed every three months, but might find it dirty after one month. Check your filters often and, if you need help remembering to change them, sign up for MTB’s email reminders

Every home operates differently, so don’t hesitate to have an MTB Comfort Specialist assist you with creating a plan for your indoor air quality. MTB’s Priority Comfort Agreement customers receive two annual maintenance visits. Schedule your visit with an MTB technician today online or by calling 704.321.9250.