When it comes to air filters, there are three main classification systems used to measure their effectiveness: MERV, MPR and FPR. MERV stands for Minimum Efficiency Reporting Value, and it is the national and international industry standard classification system established by the American Society of Heating, Refrigeration and Air Conditioning Engineers. MPR stands for Microparticle Performance Rating, and it is based on sizes from 0.3 to 1 microns. FPR stands for Filter Performance Rating, and it was developed by Home Depot, based on independent laboratory test results that compare MERV ratings. The higher the rating (for MERV, FPR and MPR), the smaller the air and dust particles your home air conditioning filter can capture.
The MERV ratings range from 1 to 16, while the FPR ratings are on a scale of 4 to 10. The main drawback of using filters with an FPR rating of 8 to 9 is that they will reduce airflow more than filters with a lower FPR rating. However, the MERV classification system is universal, making it much easier for homeowners to compare when looking for an air filter. The FPR system assigns a performance rating to an air filter based on its ability to capture particles, retain dust, and the amount of pressure drop it introduces into the system. Air filters with an FPR rating of 4 to 5 will provide a basic level of air filtration that is sufficient for most homes. The Home Depot does not provide the exact numbers they use to assign FPR ratings to air filters. The MPR system is also beneficial for homeowners looking to change the brand of air filters or compare available options.
It measures the ability of an air filter to capture particles in sizes from 0.3 to 1 microns. Unfortunately, this system is not as widely used as the MERV or FPR systems. In my opinion, the FPR system is a more complete classification system for air filters compared to the MERV and MPR systems. Any filter rated 4 to 5 on the FPR scale must be good enough to remove common household air contaminants, such as dust, lint, dust mites, pet dander, and pollen. Whether you choose the MERV classification system, the MPR system, or the FPR system, make sure you choose an air filter with an appropriate rating based on your home conditions. This will ensure that your home is properly filtered and that you are getting the best possible performance from your air filter.