When it comes to choosing the right air filter for your home, it's important to understand the Minimum Efficiency Report Value (MERV) rating system. This system, developed by 3M, classifies filters according to their ability to capture particles smaller than one micron. The MERV rating is a scale from 1 to 16 that describes the minimum efficiency of the air filter. For residential environments, MERV 12 filters are generally recommended as the highest rating.
These filters can remove up to 89% of particles that are 1.0 to 3 or 0 microns in size. Even air filters with the lowest MERV ratings, from 1 to 4, will do an effective job of preventing basic household dust from circulating. However, the best air filters for dust will also filter other allergens and contaminants. That's why air filters with a MERV rating of 5 to 8 are ideal for most homes and apartments. A filter with a MERV rating between 1 and 6 can remove particles between 0.3 and 10 microns with an efficiency of 20%.
It should also be noted that the filters at the lower end of the MERV scale are not even tested for their efficiency in capturing E1 and E2 particles. E1, E2 and E3 particles are particle range sizes used to test air filters to determine the MERV rating. Activities such as renovating the home, leaving outside doors open and having children play in the house can accelerate the accumulation of dust and particles in the air filter. To ensure you have the right amount of filter, it's best to comply with the oven manufacturer's recommendations or consult an HVAC professional to determine exactly which MERV rating is best for your specific system.