Being informed and choosing the right air filter will ensure clean air for your family and will enhance furnace efficiency and operation. Fortunately, there is a simple rating system to help you choose the right filter. It’s called MERV.


MERV is an acronym for minimum efficiency reporting value. Air filters are rated on a scale of 1-20, with 20 being the highest quality for filtering contaminants and pollutants from your indoor air. The MERV number is located on the yellow EnergyGuide label on the filter. This rating guide will help ensure that you choose the right MERV filters for your furnace.

What the Numbers Mean

Filters rated MERV 1-5 are generally only good for catching the largest of particles and dust from the air, providing very basic protection for your furnace’s operation, but not providing sufficient air-purifying qualities for your family. MERV filters rated MERV 7-13 are considered the best choice for residential use. Filters in this range won’t impede airflow, which overburdens your furnace, yet these filters provide excellent indoor-air cleaning. The next step up is pleated filters rated MERV 7-13. The design of the pleated filter allows for better air purifying, to the point of reaching a true HEPA filter MERV 17-20.

Maintaining Your Air Filters

As well as the MERV number, there are other steps that you should take to get the highest quality function from your filter.

  • Check the manufacturer’s recommendation for changing your filter. A clogged, dirty filter has reduced cleaning function, and it burdens your heating and cooling equipment. That can cost you energy dollars and system wear and tear.
  • The filter should fit properly so that there are no gaps and spaces, which results in bypass airflow. Gaps and spaces around the filter cause the dirty unfiltered air to recirculate through your home.
  • With proper filter changing and installation, you will ensure the filter efficiently catches dust mites, allergens, pollen, and pet dander from your air.

If you have any questions about improving your family’s indoor air quality, call Pipe Works Services and speak to one of our friendly professionals.

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