Furnace Filters: Which one should you buy?

Furnace Filters: Which one should you buy?


You’re standing in front of all the furnace filters at the store what you thought was an easy task has left you with questions. You start looking for the furnace filter size you need but now have questions about what brand to buy. Then you start looking at filter thickness, what type of filter, and what price point. How do you know what furnace filter to buy? Don’t worry you’re not alone. 

Honeywell, 3M, Lennox, etc,.. all familiar names, so which one do you get? Each furnace filter offers something a little different, and all of those differences can help improve or change the air quality that your furnace blows through your house. Here is some advice to help you feel confident when it comes time for you to pick up a new furnace filter. 

Furnace Filters: brands & types:

FILTER SIZE [Dimensions]: Every furnace manual comes with the filter dimensions your furnace will need. Double-check your filter size, as they vary, furnace to furnace. Your furnace filter cabinet is the chamber located between the return air and supply air sections of your furnace. Your furnace filter must fit snuggly in your furnace. Any loose gaps will allow unfiltered air to get to your blower fan. 

FILTER THICKNESS [Thickness]: The thickness of your furnace filter can range from 1″ to 5″. As a general rule of thumb, a thicker furnace filter will last longer and be more efficient. However, these filters often come with a higher price tag. We suggest a thicker filter for those with furry pets in the house, but only when your furnace allows. The average furnace filter thickness we see used is 2”-3”. Consult your HVAC Specialist to determine the thickness of the filter that you can use.

FILTER PRICE: Furnace filters come at all prices. Pricing doesn’t always seem to reflect quality. Overall, if price dictates your purchase, make sure you are changing your furnace filters regularly if you choose a budget-friendly option. Otherwise, think about your home and consider furnace filter types based on your living atmosphere.


Basic Filters: Help capture the dust, lint, hair, and debris from getting into your blower fan. These filters offer the first line of defense for furnace maintenance. 

Allergen Filters: Help capture dust and lint, airborne dust mite debris, pollen, pet dander, mold spores, bacteria, microscopic allergens, and most smoke. Allergen Furnace Filters help provides cleaner air quality as it circulates through your home. 

Odor Reduction Filters: Helps neutralizes common household odors by eliminating offensive odors and reducing harmful allergens, dust, mold spores, and more. This furnace filter option is for those who smoke or cook greasy foods in their home. 

Filter Rating: [MERV] It is wise to understand MERV (Minimum Efficiency Reporting Value) ratings when buying your furnace filters. You will see ratings range from a low of 1 to a high of 20. The lower the MERV rating, the less protection you will get from your furnace filter. On the contrary, the higher the rating, the more particles the filter can remove. However, this also allows less airflow, which can cause an issue with your furnace. According to the United States Environmental Protection Agency, air furnace filters with a MERV between 7 and 13 will be adequate for most homes.


We suggest you check your furnace manual or get advice from your HVAC Specialist to see what MERV rated furnace filter will work best with your heating unit.

Remember that when changed and maintained regularly, furnace filters can extend the life of your heating system. They can also help keep maintenance costs down.

The primary purpose of a furnace filter is to protect HVAC equipment, with the added benefit of improving indoor air quality. Regular duct cleaning also plays a critical role in your furnace and home air quality.

If you are looking to significantly improve indoor air quality talk to us about a quote for installing an air cleaning and filtration system. Always on Call, Mountain Mechanical, Call us Today!