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 suggest using the filter your HVAC manufacturer suggests pairing with your unit.

All filters are classified with MERV ratings, which range from 1–20. MERV is short for minimum efficiency reporting value.

A bigger value means the filter can trap more miniscule substances. This sounds outstanding, but a filter that catches finer substances can become blocked more quickly, raising pressure on your unit. If your system isn’t designed to work with this kind of filter, it can reduce airflow and lead to other problems.

Unless you live in a medical facility, you likely don’t need a MERV level higher than 13. In fact, the majority of residential HVAC units are specifically designed to work with a filter with a MERV ranking below 13. Sometimes you will discover that decent systems have been engineered to operate with a MERV ranking of 8 or 11.

All filters with a MERV rating of 5 should trap the majority of the daily annoyance, such as pollen, pet dander and dust. Some filters say they can trap mold spores, but we recommend having a professional eliminate mold as opposed to trying to mask the problem with a filter.

Usually the packaging demonstrates how frequently your filter should be replaced. From what we know, the accordion-style filters work better, and are worth the additional cost.

Filters are created from differing materials, with one-use fiberglass filters being the most common. Polyester and pleated filters grab more debris but may limit your system’s airflow. Then there are HEPA (high efficiency particulate air) filters.

While you could tempted to use a HEPA filter, keep in mind that's like installing a MERV 16 filter in your heating and cooling equipment. It’s highly unlikely your system was made to run with kind of resistance. If you’re troubled by indoor air quality in Charleston, think about adding a HEPA-grade air filtration system. This unit works along with your comfort system.