MERV ratings are a way of measuring the efficiency of air filters. They are determined by adding particles of different sizes in a controlled test environment. A laser particle counter is used to sample the air before and after it passes through the filter. The MERV rating of a filter describes the size of the holes that allow air to pass through.
The higher the MERV rating, the smaller the holes in the filter, and the higher its efficiency. In order to calculate a filter's MERV rating, a detachment penalty is eliminated and a calculated release rate is added. This helps to determine how well the filter can capture particles of different sizes. It's important to understand MERV ratings when selecting an air filter for your home or business.
A higher MERV rating means that the filter will be more effective at capturing particles, which can help improve air quality and reduce allergens. It's also important to note that filters with higher MERV ratings may require more frequent replacement, as they can become clogged more quickly.