When it comes to air filtration, two of the most important ratings to consider are the MERV and FPR ratings. Established by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE), the MERV rating evaluates a filter's ability to capture and retain particulates and contaminants. On the other hand, 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. In this article, I'll explain the differences between these two ratings and discuss which one is best for your home.
MERV RatingThe MERV rating is on a scale of 1 to 16, with higher numbers indicating better filtration. Generally speaking, MERV 8 filters can filter 90% of the particles suspended in the air, MERV 11 can remove around 95%, and MERV 13 can block approximately 98%. However, if the MERV rating is too high (above MERV 1), it can increase system backpressure and block air flow through the central air system, worsening the efficiency of the air conditioning system.
FPR RatingThe FPR Rating is on a scale of 4 to 10. This system takes into account both the pressure drop and dust-holding capacity of air filters.
In addition, filters with an RPF rating of 4 to 5 will not restrict airflow as much as filters with a higher RPF rating. In my opinion, the FPR system is a more complete classification system for air filters compared to the MERV and MPR systems.
Which Rating is Best?When it comes to choosing an air filter for your home, it's important to consider both ratings. Generally speaking, if you have an older HVAC system, you may want to opt for a lower MERV rating (MERV 8 or 11) in order to avoid overloading the system.
On the other hand, if you have a newer unit, you may want to opt for a higher MERV rating (MERV 11 or 13) in order to get better filtration. As for FPR ratings, I recommend opting for an FPR rating of 6 or higher in order to get maximum filtration.
ConclusionWhen selecting an air filter for your home, it's essential to take into account both MERV and FPR ratings. If you have an older HVAC system, opt for a lower MERV rating (MERV 8 or 11) in order to avoid overloading it.
For newer units, choose a higher MERV rating (MERV 11 or 13) for better filtration. As for FPR ratings, go for an FPR rating of 6 or higher for maximum filtration.