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Choosing the Right HVAC Filter

We’re in the middle of the peak heating season here in Kansas City, which means it’s important you keep up with proper HVAC maintenance. Are you replacing your HVAC unit’s air filter once a month? If not, you should be! HVAC filters have become increasingly important because they have a significant impact on indoor air quality and energy efficiency. A dirty filter hurts the unit’s energy efficiency and causes the HVAC system to be overworked.

A recent study by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) has shown that dirty filters can reduce HVAC efficiencies by 10 percent or more. How do you go about choosing the right HVAC filter? You need to be aware of the different HVAC filters available to you as well as their Minimum Efficiency Reporting Value (MERV), a measure of the effectiveness of the filter. Inefficient HVAC filters have a lower MERV rating while more efficient ones boast a higher MERV rating. Top Notch Heating, Cooling & Plumbing sorts out the different options you have.

HVAC Filter #1: Fiberglass Filters

It’s really not in your best interest to use fiberglass filters for your HVAC unit—they are very thin and feature just a basic flat panel surface for trapping air particles. Fiberglass filters were developed to protect your HVAC unit, not to improve indoor air quality. These filters typically sell for $1 apiece, and they remove less than 10 percent of the air pollutants from your home. Fiberglass filters usually have a MERV rating between one and four.

HVAC Filter #2: Polyester and Pleated Filter

Polyester and pleated filters are pretty similar to fiberglass filters, but they tend to have superior dust-trapping ability. These HVAC filters remove up to 45 percent of the air pollutants in your home. They typically cost around $10 each and have a MERV rating between eight and 13.

HVAC Filter #3: Washable Air Filters

Most HVAC technicians will agree that washable air filters are the worst HVAC filters you can purchase. These filters usually have a very low MERV rating—between one and four—and require extensive maintenance. They easily collect fungus and bacteria, which can escape and circulate throughout your home. You should avoid using washable air filters for your HVAC unit.

HVAC Filter #4: High-Efficiency Filters

High-efficiency HVAC filters can remove up to 85 percent of the air pollutants from a home or building space. They boast a MERV rating between 14 and 16 (16 is the highest rating). Often made using pleated filter paper or synthetic polyester fibers, high-efficiency filters can trap very small particles of dust, pollen, mold, and other irritants. These filters, however, are not very practical for residential use—hospitals or other “clean-room” environments use these industrial air filters to remove even the bacteria from the air.


Keep in mind that the best HVAC filter for your heating or air conditioning system might not be the one with the highest MERV rating. An overly restrictive air filter can slow the rate of airflow, causing your unit to malfunction. The ideal air filter is one that has the least effect on airflow, but removes the greatest number of air contaminants.

Filters with a MERV rating between nine and 12 are usually the best choice for homeowners who want the best dust control possible. Contact us if you want to learn more about HVAC filters or need help replacing your unit’s filter.