Minimum Efficiency Reporting Value (MERV)
MERV ratings measure an HVAC filter's effectiveness in capturing particles, indicating how well the filter removes contaminants like dust, pollen, and smoke from the air. Higher MERV ratings mean better air filtration and improved indoor air quality.
Dust, Pet Dander, Pollen, and Air Filters: Understanding MERV Ratings
Air filters are essential to improving indoor air quality (IAQ) by capturing small pollutants like dust particles, pet dander, pollen, and other airborne particles. These tiny particulates are measured in microns, and to put it in perspective, a human hair is approximately 50 microns in diameter. The effectiveness of air filters in capturing these particles is rated by MERV, or Minimum Efficiency Reporting Value.
MERV Rating Levels Explained
MERV ratings range from 1 to 16, with ratings above MERV 16 classified as HEPA filters, which are typically used in specialized environments. The higher the MERV rating, the more effective the filter is at capturing smaller particles, though higher MERV filters also increase system resistance. Your HVAC system may not support higher MERV filters due to airflow restrictions, so consult your HVAC professional to select the appropriate filter.
| Particle Type | MERV 8 (3-10 microns) | MERV 11 (1-3 microns) | MERV 13 (0.3-1 microns) |
|---|---|---|---|
| Pollen | X | X | X |
| Dust | X | X | X |
| Dust Mites | X | X | X |
| Mold Spores | X | X | X |
| Lint | X | X | X |
| Bacteria/Fungi | X | X | |
| Pet Dander | X | X | |
| Skin Flakes | X | X | |
| Hair | X | X | |
| Viruses | X | ||
| Tobacco Smoke | X | ||
| Cooking Smoke | X | ||
| Smog | X |
Which MERV Rating Do You Need?
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MERV 8: This basic filter captures larger particles like dust, pollen, and mold spores. It’s a good budget option but may not be effective at filtering finer pollutants, which can decrease IAQ.
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MERV 9-12: These filters are better for households with pets or allergy sufferers. A MERV 11 filter, for example, captures particles like dust, pollen, mold spores, pet dander, and lint more effectively.
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MERV 13: Ideal for those with respiratory concerns, MERV 13 filters can trap smoke, smog, and some airborne viruses, in addition to all that MERV 11 can capture. Trane’s QuikBox™ Air Cleaner is available in MERV 11 and MERV 13 options.
For enhanced filtration, the Trane CleanEffects® Whole-Home Air Cleaner captures 99.8% of airborne particles, significantly improving IAQ by filtering out contaminants before they enter your HVAC system.
MERV vs. MPR Ratings
The MPR (Microparticle Performance Rating) specifically measures a filter’s efficiency at capturing particles between 0.3 and 1 micron. Filters with high MERV or MPR ratings are usually pleated and electrostatic, which makes them highly effective at filtering out microparticles and improving IAQ.
Choosing the Right HVAC Filter
When selecting an HVAC filter, consider your budget, whether anyone in the household has allergies or asthma, and the presence of pets. Higher MERV or MPR ratings capture more particles, leading to cleaner air. Regularly changing your filter helps maintain air quality and allows your HVAC system to operate efficiently.
