Are all HVAC air filters the same?

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

All filters are assigned MERV ratings, which go from 1–20. MERV means minimum efficiency reporting value.

A bigger value demonstrates the filter can catch finer substances. This sounds good, but a filter that stops finer dirt can clog faster, raising pressure on your unit. If your equipment isn’t created to function with this kind of filter, it can decrease airflow and lead to other troubles.

Unless you reside in a hospital, you likely don’t require a MERV ranking greater than 13. In fact, the majority of residential HVAC units are specifically made to run with a filter with a MERV level below 13. Frequently you will learn that decent systems have been engineered to run with a MERV rating of 8 or 11.

All filters with a MERV rating of 5 should trap many daily annoyance, such as pollen, pet dander and dust. Some filters assert they can catch mold spores, but we suggest having a professional eliminate mold rather than trying to mask the problem with a filter.

Usually the packaging shows how often your filter should be changed. From what we’ve seen, the accordion-style filters last longer, and are worth the extra cost.

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

While you might be interested in using a HEPA filter, remember that's like installing a MERV 16 filter in your comfort unit. It’s highly unlikely your system was made to run with level of resistance. If you’re concerned about indoor air quality in Toronto, think about adding a HEPA-grade air filtration system. This equipment works along with your comfort system.