Specifying Residential Air Filters
Air filtration should not be taken lightly. Most residential air filters are contained within the home’s air handling unit and are typically a one-inch pleated type with a MERV (Maximum Efficiency Reporting Value) rating of 5.
What is MERV? This filter rating system used in the air conditioning industry.
MERV 5 filters have the ability to remove dust particles the size of pudding mix or powdered milk. All other sized dust particles will pass through. Mold spores are not removed from the air stream until you get to a MERV 8 filter, Legionella at MERV 12, and bacteria MERV 16.
So what is the correct filter for you?
The American Lung Association recommends using a minimum of MERV 8 filters in residential applications. People who suffer from asthma and allergies should use a filter rating of at least MERV 11. Why not go higher? Filters with a very high MERV rating over MERV 13 are designed for special commercial applications such as hospitals and clean rooms. These filters restrict the airflow to the extent they could cause damage to residential air handling units. For residential applications a one-inch MERV 8 filter should be used and if higher levels of filtration are needed, a portable air cleaner that employs a HEPA (high-efficiency particulate air) or MERV 16 filter should be implemented.
The higher the MERV number the more often the filter needs to be changed to avoid restricting air flow and loss of system efficiency.
1-Inch Synthetic Pleated Filter MERV 8
5-Inch Pleated Air Filter MERV 8