MERV stands for Minimum Efficiency Reporting Value and is a system used to evaluate the efficiency of an air filter based on its effectiveness in capturing particles of different sizes. Established in 1987 by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), MERV is the only standardized filter rating system. A MERV 8 filter is the most common type of filter used in residential HVAC systems, but a MERV 11 filter offers more protection against airborne particles. A MERV 11 filter has a larger surface area than a MERV 8, which means it can capture more particles and last longer.
It is also better able to capture 65% to 79% of the smallest particles, such as pet dander, lung-damaging dust, and trapped self-emissions. MERV 11-13 air filters are a kind of midpoint between the cheapest and the most expensive. They are efficient at capturing almost all the largest particles, as well as most of the smallest particles. If you have pets, a MERV 11-13 filter will be much more effective at cleaning indoor air.
These air filters provide highly effective residential air filtration for a much healthier breathing environment. The higher the MERV rating, the more airborne pollutants the air filter can remove before entering your home. It is essential to remember that the MERV rating of an air filter denotes its lowest possible capacity, that is, the minimum percentage of impurities it could effectively filter. Schools often use MERV 13 air filters to provide clean learning environments for their students and staff. Although MERV 11 filters are slightly more expensive, at a cost of a few dollars, they can improve indoor air quality to help relieve people with respiratory problems.
At the heart of an optimally functioning HVAC system is an oven filter with the right MERV rating for you. A high MERV filter also means that the HVAC system has to work harder because there is more to block airflow. A MERV 14 or higher air cleaner can create more resistance in the airflow than a residential HVAC system is designed to withstand. Therefore, it is in the best interest of every homeowner to analyze the MERV rating system, what it entails and what rating would be right for their air filtration needs.