Are all HVAC air filters the same?

No, HVAC air filters differ in quality and size, and some have specifications that others don't. In most cases we advise installing the filter your HVAC manufacturer says to pair with your equipment.

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

A higher value demonstrates the filter can catch smaller particles. This sounds outstanding, but a filter that traps finer substances can become obstructed more quickly, raising pressure on your unit. If your equipment isn’t created to work with this kind of filter, it might decrease airflow and cause other problems.

Unless you are in a medical facility, you probably don’t require a MERV ranking above 13. In fact, most residential HVAC units are specifically made to operate with a filter with a MERV rating under 13. Frequently you will discover that decent systems have been designed to operate with a MERV ranking of 8 or 11.

All filters with a MERV level of 5 should catch most of the everyday annoyance, like pollen, pet dander and dust. Some filters say they can stop mold spores, but we recommend having a professional remove mold rather than trying to conceal the problem with a filter.

Usually the packaging demonstrates how regularly your filter should be changed. From what we’ve seen, the accordion-style filters work better, and are worth the added price.

Filters are manufactured from varying materials, with single-use fiberglass filters being standard. Polyester and pleated filters grab more dust but may decrease your equipment’s airflow. Then there are HEPA (high efficiency particulate air) filters.

While you might tempted to use a HEPA filter, remember that's like adding a MERV 16 filter in your HVAC system. It’s extremely unrealistic your equipment was created to work with amount of resistance. If you’re concerned about indoor air quality in Knoxville, think about installing a HEPA-grade air filtration system. This product works along with your HVAC system.