Are all HVAC air filters the same?

No, HVAC air filters are different in quality and size, and some have specifications that others don't. In most instances we suggest using the filter your HVAC manufacturer recommends pairing with your equipment.

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

A larger ranking demonstrates the filter can grab finer particulates. This sounds great, but a filter that traps finer dust can become blocked more rapidly, increasing pressure on your equipment. If your system isn’t made to function with this model of filter, it can restrict airflow and create other troubles.

Unless you are in a hospital, you probably don’t have to have a MERV rating higher than 13. In fact, the majority of residential HVAC units are specifically designed to work with a filter with a MERV level under 13. Occasionally you will learn that decent systems have been designed to work with a MERV rating of 8 or 11.

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

Usually the packaging indicates how frequently your filter should be changed. In our experience, the accordion-style filters work better, and are worth the added expense.

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

While you could be interested in using a HEPA filter, keep in mind that's like putting a MERV 16 filter in your HVAC equipment. It’s highly doubtful your equipment was designed to work with amount of resistance. If you’re concerned about indoor air quality in Calgary, think over adding a HEPA-grade air filtration system. This product works along with your HVAC system.