MERV ratings are a scale from 1 to 16 that measure the minimum efficiency of air filters. A MERV 9 filter will trap less than 50% of particles of size 1, 0-3.0 microns, while a MERV 10 filter will stop up to 64%. Merv 11 air filters are capable of trapping 79% of particles 1 to 3 microns in size and 85% of particles 3 to 10 microns in size.
Merv 11 air filtersare slightly more expensive than standard filters, but they are worth it for the added efficiency.
In some cases, a higher MERV rating is necessary. If someone has an allergy or respiratory problem, a MERV 11 or even a MERV 13 air filter should be used. The same applies to households with smokers or pets, as MERV 11 air filters better eliminate odors. Filters with a MERV rating of 16 to 20 are usually only found in hospitals, cleanrooms, and nuclear power plants.
Both MERV 8 air filters and MERV 11 air filters are suitable for residential use. MERV 8 air filters are very common and offer a good price-performance ratio. The worst percentage of the six tests is selected as the official measure used to determine the MERV rating of a filter. The goal of using a MERV 12 or higher filter is to achieve better Indoor Air Quality (IAQ) by providing cleaner, more breathable air for everyone, especially those with allergies, asthma, COPD, etc.
The higher the MERV index of a filter, the less dust particles and other contaminants can pass through it. E1, E2, and E3 particulates are particle range sizes used in air filter testing to determine a MERV rating. When selecting an air filter, it is best to adhere to the oven manufacturer's recommendations or consult an HVAC professional to determine which MERV rating is best for your specific system. A filter with a MERV rating of around 10 to 12 is enough to remove most allergy-causing particles from your home's air.
The Minimum Efficiency Report Value (MERV) rating system is used to compare filters manufactured by multiple manufacturers. It is important to note that if your HVAC has a permanent split condenser fan, a higher MERV rated air filter will interfere with it and cause lower airflow. Choosing the right MERV rating is an important decision in terms of overall cost, air quality, and product durability.