Understanding HVAC Filters: MERV, Location, Types

When it comes to both the long-term quality of your air and the long-term effectiveness of your entire HVAC system, few items are more important than filters. Responsible for trapping contaminants and stopping them from entering your breathing air, HVAC filters play a vital role here while also allowing proper airflow throughout the system.

At FLAME Heating & Cooling, we’re here to help with numerous commercial and residential HVAC service areas in Michigan, including assistance with filters in any way you might require it. For those unfamiliar with HVAC filters and their specifics, including those who have recently bought or moved into a house and need to know how to utilize them properly, this two-part blog series will dig into everything you should know about air filters.

MERV Rating

As we noted above, the primary role of HVAC filters is to trap contaminants, which is done by blocking them with filter material. Homeowners naturally want to know how effective specific filters will be at blocking different particulates, and the metric used here is MERV rating.

Short for Minimum Efficiency Reporting Value, MERV specifically speaks to how well a given filter traps particles. It ranges from 1 (the lowest possible filtration rating) to 20 (extremely efficient filtration). Numbers on the higher end of this scale are only found in medical facilities or other special buildings, not in homes. Typical houses will have filters ranging from 10-14 on the MERV scale, depending on factors like whether you have pets, how many people live in the home, etc.

Filter Location

Where does the filter go? The answer is the same for nearly all HVAC systems: In what are called return vents, which typically sit right alongside your furnace. Homes have anywhere from one to three return vents (mostly determined by your home’s square footage), but some might have four or more. You don’t always need more than one filter for multiple return vents, but there could be situations where this is advised.

Washable Vs Disposable

There are two types of HVAC filters: Washable and disposable. The latter is the more common type, generally requiring replacement every one to three months as dirt, dust and other debris have built up in the filter.

For those who are going eco-friendly, however, washable filters might be used. These filters won’t have the same MERV rating capacity, however, and generally provide slightly lower-level filtration; this is fine for many homes, but some may still prefer disposable filters due to both filtration quality and the time it takes to wash filters.

For more on air filters in your HVAC system and why they matter, or to learn about any of our HVAC, electrical or plumbing services, speak to the staff at FLAME Heating & Cooling today.