Air Filters, Pollutants and MERV: Read All About ThemHave you tried to buy new air filters for your home or business? If so, you’ve seen shelf after shelf of filters, all different sizes, types and ratings. The effectiveness of an air filter is based on its ability to remove particles from the air that passes through it. The system is called MERV, or Minimum Efficiency Reporting Value.

The following list describes the various MERV ratings (from 1 to 20, higher is generally better) and their uses:

1-4:  These are usually disposable filters used in house furnaces and air conditioning systems. They filter out particles of 10 ppm or larger. These particles include pollen, dust mites, sanding or spray paint dust, and household fibers. Pet allergens are also handled by these filters

5-8:  These are better filters found in commercial buildings and some residences. The particles filtered include 3-10 micrometers plus those covered by the 1-4 MERV filter. Common particles include mold spores and hair spray.

9-12:  These air filters are usually present in hospital labs, some commercial settings and rarely in homes. They filter very small particles, 1-3 micrometers is standard. Particles filtered by these can include milled flour, welding dust and Legionella.

13-16:  You can find these filters in general surgery and smoking lounges. Particles filtered can be as small as 0.3-1.0 micrometers. Bacteria and tobacco smoke are the common reasons to install a filter with this capability.

17-20:  These highly specialized filters are for clean rooms, radioactive material handling, and carcinogens. They filter particles smaller than 0.3 micrometers, which include viruses and even carbon dust. These filters are known as HEPA, or High Efficiency Particulate Air filters.

Most homes will have filters that fall into the 1-8 MERV rating. Higher ratings may require changes to your air conditioning system because the filter increases airflow resistance.

For other answers to your Los Angeles County air conditioning needs, please contact us. We have been in business since 1967, and have trained professionals ready to meet your needs. Call now or schedule an appointment online!

Our goal is to help educate our customers in Los Angeles, North Hollywood and surrounding areas about energy and home comfort issues (specific to HVAC systems).  For more information about home pollutants and other HVAC topics, download our free Home Comfort Resource guide.

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