Understanding MERV Ratings in Air Filters

Air filters
Image Source: Filterking

When you purchase an air filter, one of the most important aspects to look at is the MERV rating. It is a significant rating that determines the efficiency of the air filter. Here’s what you need to know about MERV ratings to understand them better.

What Does MERV Rating or MERV Mean? 

MERV is short for Minimum Efficiency Reporting Value. It is a rating developed by the American Society of Heating Refrigeration and Air Conditioner Engineers to determine the filter's effectiveness. The MERV ratings fall in the range of 1 to 16. The higher the MERV rating, the more efficient the filter is.

The best filters you can buy are from https://filterking.com/, which are tested for mites, dust, mold spores, pollen, bacteria, tobacco smoke, pet dander, textile, and carpet fibers. Most residential HVAC systems can adequately remove contaminants with air filters with MERV ratings in the range of 7 and 12. On the other hand, air filters with higher MERV ratings between 13 and 16 work for general surgery and hospital settings.

MERV Ratings and Minimum Size of the Particles It Can Capture

An air filter with a MERV value in the range of 1 and 4 can capture particles bigger than 10 micrometers. It includes household debris, dust, mites, and bugs. Most HVAC system air filters from https://filterking.com/ fall within this MERV range.
  • The air filter with a MERV rating of 5 to 8 can capture particles greater than 3 micrometers. This includes pet dander, aerosol sprays, and molds, Most residential HVAC system air filters fall in this MERV range.
  • An air filter with MERV value in the range of 9 and 12 can trap particles higher than one micrometer. It includes common pollutants and fine dust. Superior residential and hospital HVAC systems have such high MERV value air filters.
  • An air filter with a higher MERV value like 13 to 16 is not for general use. It can trap droplets from sneezing, smoke, bacteria, and other sources of pollution. This level of air filtration is essential for surgery areas of the hospital.
  • Air filters with MERV value between 17 and 20 have superior air filtration capabilities. They can capture the finest particles of dust, viruses, smoke, and debris. These air filters are ideal in manufacturing facilities of electronics or scientific experiment labs.

When to Replace the Filter by MERV Rating? 

The air filters work continuously by trapping the dirt particles and other pollutants. As time passes, the filter membrane becomes clogged due to trapped dirt particles and debris. It affects the flow of the air, which in turn affects the efficiency of the HVAC system. Hence HVAC system experts advise consumers to replace air filters regularly. here are some guidelines when to change air filters by MERV ratings
  • Air filters with MERV value 6 need to be changed every 30 days
  • Air filters with MERV rating 8 should be changes 60 to 90 days
  • Air filters with MERV values 11 and 13 also need to be changed every 2 or 3 months. 

Higher Is Not Always Better

You might think an air filter with a higher MERV value is what you need. However, this is not always right. Higher the MERV rating, the smaller pores the air filter membrane has. Small pores get clogged faster. When the pores are clogged, it affects the airflow in your home that can worsen air quality in your home.