Factors to Consider When Buying a Furnace Filter

Factors to Consider When Buying a Furnace Filter

Hands Changing Furnace Air Filter

Are you coughing or sneezing at home? Are you experiencing increased allergy symptoms? You aren’t alone. Millions of people around the world suffer from symptoms caused by allergens and dust in their homes. Particles such as pollen, pet dander, insect droppings, and dust can trigger allergic reactions that are accompanied by coughing, sneezing, and a runny nose. Allergy symptoms and other indoor air quality issues could be caused by a dirty furnace air filter.

Changing your furnace’s air filter on a regular basis helps protect your home from dust, debris, and other airborne particles, but not all air filters are created equal. Choosing the best filter requires matching the filter to the furnace manufacturer’s specifications. Just because one filter blocks more particles than another doesn’t mean it’s the right choice for your furnace. This article will discuss what factors to consider when choosing the best furnace air filter for your home:

Filter Size

Furnace filters come in several sizes, with 16×20 inch, 20×25 inch, and 16×25 inch being the three most common sizes. Filters not only vary in size but also in thickness. Filter thickness usually ranges between one and five inches. In general, the thicker the filter the more particle-blocking ability it will have. You will need to check your furnace owner’s manual before choosing a filter because not all furnaces will accept a thicker product. When the filter is thicker, the furnace must work harder to pull air through it. This will reduce system efficiency and lifespan if the furnace is not built to accommodate the thickness of the filter you chose to install.

Washable vs. Disposable

Disposable filters are relatively cheap, lightweight, and can be thrown out after a new filter is installed. Washable filters have a larger, heavier frame and use electrostatic fibers to filter out debris and allergens. Washable filters can last up to a few years and require a specific washing procedure that is dependent on which brand you use. It is also important to note that washable filters must dry completely before being re-installed to prevent mold and mildew growth. Because of the somewhat complex cleaning process, using a disposable filter is more popular than using a washable filter for your furnace.

MERV Rating

Furnace filters are assigned a minimum efficiency reporting value (MERV) based on their density. Values are assigned to air filters to determine their efficiency in terms of removing particles from the air. The more dense or higher the MERV rating, the more airborne particles are trapped. While denser filters trap more particles, they also need to be changed more frequently because they tend to clog up more quickly. The MERV scale goes from 1 to 20, and filters between the range of 6 and 12 are generally used for residential use. Refer to your furnace’s operating manual to determine the ideal MERV rating that is best suited for your particular unit.


The climate you live in can play a factor in the type of furnace filter that is best for your home. In damp or rainy areas, mold and mildew growth are common concerns. So, if you live in a humid climate, you will want to choose a filter with a MERV rating above 6 to prevent mold spores from being drawn into the furnace and then recirculating inside your home.

Choosing the Best Filter for Your Home

In order to choose the best furnace filter for your home, you should consider the following factors: size, washable vs. disposable, MERV Rating, and climate. The best furnace filter should protect your furnace, trap debris and pollen, and prevent airborne particles from recirculating in your home. Contact Certified Heating and Air Conditioning today for all of your HVAC needs. One of our trained technicians will be happy to assist you.

Works Cited:

  • https://www.familyhandyman.com/project/choosing-furnace-filters
  • https://www.bobvila.com/articles/best-furnace-filter/
  • https://airfiltersdelivered.com/blogs/helpful-tips/learn-which-are-the-best-air-filters-for-allergies-asthma
  • https://www.hvac.com/furnaces/furnace-filters-101/