Are all HVAC air filters the same?

No, HVAC air filters vary in quality and dimensions, and some have specifications that others don't. In most situations we advise getting the filter your HVAC manufacturer recommends pairing with your unit.

All filters have MERV ratings, which range from 1–20. MERV stands for minimum efficiency reporting value.

A higher rating means the filter can trap more miniscule substances. This sounds great, but a filter that stops finer dirt can become obstructed more rapidly, heightening pressure on your unit. If your equipment isn’t made to function with this kind of filter, it might lower airflow and cause other issues.

Unless you are in a medical facility, you likely don’t need a MERV rating above 13. In fact, most residential HVAC units are specifically made to operate with a filter with a MERV level below 13. Occasionally you will find that decent systems have been engineered to operate with a MERV rating of 8 or 11.

All filters with a MERV rating of 5 should catch the majority of the common triggers, such as pollen, pet dander and dust. Some filters claim to be able to trap mold spores, but we advise having a professional remove mold instead of trying to hide the issue with a filter.

Usually the packaging shows how frequently your filter should be changed. In our experience, the accordion-style filters hold up better, and are worth the added cost.

Filters are created from different materials, with single-use fiberglass filters being standard. Polyester and pleated filters catch more debris but may limit your equipment’s airflow. Then there are HEPA (high efficiency particulate air) filters.

While you might tempted to use a HEPA filter, keep in mind that's like adding a MERV 16 filter in your comfort equipment. It’s highly doubtful your system was designed to run with amount of resistance. If you’re worried about indoor air quality in Charlotte, think over adding a HEPA-grade air filtration system. This unit works in tandem with your HVAC system.