MERV ratings are the national and international industry standard classification system established by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE). This system rates air filters based on their ability to capture particles, ranging from 1 to 16.On the other hand, FPR ratings are a system developed by The Home Depot for brands sold in its stores, including Honeywell. This rating system is based on a color code and a numerical scale from 4 to 10, which is similar to the MERV classification. The FPR system goes one step further than the MERV system and also classifies filters according to the amount of pressure drop they introduce and their dust retention capacity.
The higher the rating (for MERV, FPR and MPR), the smaller the air and dust particles your home air conditioning filter can capture. For example, MERV 8 filters can generally filter 90% of the particles in the air, while MERV 11 can remove about 95%, and MERV 13 can block approximately 98%. The Home Depot does not provide exact numbers they use to assign FPR ratings to air filters. However, it is important to note that filters with an FPR rating of 4 to 5 will not restrict air flow as much as filters with higher FPR ratings.
Therefore, it is important to choose an air filter with an appropriate rating based on your home conditions. In conclusion, while both MERV and FPR ratings are used to measure air filter performance, they are not exactly the same. The MERV system qualifies air filters strictly according to their ability to capture particles, while the FPR system also classifies filters according to the amount of pressure drop they introduce and their dust retention capacity. Therefore, it is important to understand both systems in order to choose an appropriate air filter for your home.