When you head to the store to replace your AC filter, you’ll notice a variety of numbers printed on the packaging. Whether it’s a MERV 8, an MPR 1000, or an FPR 7, every air filter rating is designed to tell you one thing: how well that filter cleans your air.
However, because different brands use different scales, it’s easy to get confused. We want to help you understand which air filter rating is right for your home’s air quality and your system’s health.
Why Is the Air Filter Rating Important?
The air filter rating is more than just a marketing number. It measures the filter’s ability to trap specific sizes of particles, such as dust, pollen, pet dander, and bacteria.
Choosing the correct air filter rating is a balancing act. If the rating is too low, dust can build up on your AC coils. If the rating is too high, the filter may be so thick that it restricts airflow, causing your system to overwork and potentially leading to costly repairs.
Recommended Reading: How Often Should I Change My AC Filter?
The Three Main Air Filter Rating Systems
1. MERV (Minimum Efficiency Reporting Value)
The MERV air filter rating is the universal industry standard. Developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), MERV is used by almost all HVAC professionals to compare filters across different brands.
- The Scale: 1 to 16
- The Goal: To provide a reliable, independent measurement of filtration efficiency.
2. MPR (Microparticle Performance Rating)
This air filter rating was developed by 3M (Filtrete). It focuses specifically on the filter’s ability to capture the smallest “microparticles,” like smoke, cough particles, and viruses.
- The Scale: 300 to 2800
- Pro Tip: An MPR 1000 is roughly equivalent to a MERV 11 air filter rating.
3. FPR (Filter Performance Rating)
FPR is the air filter rating system used exclusively by The Home Depot for brands like Honeywell. It uses a color-coded scale to help consumers make a quick choice in the aisle.
- The Scale: 1 to 12
- Pro Tip: FPR 5 is a standard residential air filter and compares to MERV 8.
MERV, MPR and FPR Filter Ratings Conversion Table
What Air Filter Rating Should You Use?
For most Florida homeowners, we recommend an air filter rating of MERV 8.
- MERV 8 is the residential standard and places minimal strain on your HVAC system.
- MERV 11 is ideal for pet owners and allergy sufferers, provided your HVAC system is capable of handling the additional airflow resistance.
We generally advise against using a MERV 13 air filter rating or higher in a standard residential system unless it was specifically designed for it, as the high density can “choke” your air conditioner’s airflow.
Still Unsure About Your Air Filter Rating?
Choosing the wrong filter can impact your comfort and your wallet. If you’re worried about your home’s airflow or want to upgrade your indoor air quality, let us know and we’ll be glad to help!
