When it comes to air filtration, two of the most popular rating systems are the Minimum Efficiency Reporting Value (MERV) and The Home Depot's Air Filter Rating Method (FPR). The MERV system ranges from 1 to 20, while the FPR system ranges from 1 to 12. The FPR 10 has a similar strength to that of the MERV 20, since both have the highest rating value. In addition, filters with an FPR rating of 4 to 5 will not restrict airflow as much as filters with a higher FPR rating. This means that there are no designated equivalents for MERV 14, MERV 15, and MERV 16 on the FPR scale.
If you compare the MERV and FPR rating factors, you'll see that the MERV score uses only 1 broad-based metric, while the FPR score uses 4 more specific metrics. To help you understand the differences between these two systems, we've created a comprehensive guide that explains how to convert between MERV versus FPR and FPR versus MERV. Newer units shouldn't have airflow problems with higher MERV ratings, although older models can work harder with a MERV 13 filter installed than when they originally had a MERV 6 filter in the air intake. In these cases, a MERV 11 air filter can offer additional benefits and capture a wider range of particles that would pass through a MERV 8 filter.
The FPR system takes into account the pressure drop and dust-holding capacity of air filters, aspects that MERV and MPR systems do not address. As you can see, the FPR ratings are color-coded (FPR under 4 and FPR 5 are green, FPR 6 and FPR 7 are red, FPR 8 and FPR 9 are purple, and FPR 10 is black). MERV 13 air filters provide even greater filtering power against fine particles compared to MERV 11 filters. In conclusion, it is important to understand the differences between these two rating systems when it comes to air filtration. The FPR system is a more complete classification system for air filters compared to the MERV and MPR systems.
With our guide, you'll be able to properly convert between the two systems.