Does Furnace Filter Affect Air Conditioning?

Everyone knows that a furnace filter helps to keep dust smoke and pollen from circulating throughout your house.  

Even though an air filter on your furnace keeps dust smoke and pollen out of your ventilation and home, it may affect your air conditioning quality and consistency.

A furnace filter can affect air conditioning by dirtying your air conditioning or heating units as well as the ducks where the air travels. A dirty air filter can cost you a lot of money for HVAC cleaning.

 A furnace filter is an excellent addition to your heating and cooling system because it helps filter out pollen and dirt.

However, if you don’t occasionally replace your air filter, it could affect your air conditioner’s cleanliness. This article will give you some tips and tricks on how to best care for a furnace filter and your air conditioning health.

Furnace Filters Affect Air Conditioning 

There are both positive and negative to having a furnace filter on your air conditioning unit.

Keep the filter clean and replace it when it gets dirty. There are many benefits to using a clean furnace air filter with an air conditioning system. 

If you cannot change your furnace Air filter when he gets dirty, though, came potentially be problems for your air conditioner.

It is essential to check your furnace air filter’s health and quality to ensure that it does not negatively affect your air conditioner.

Air conditioners use the air intake from the furnace to run their systems, as well. So, if you have a dirty air filter on your furnace it could negatively impact the function and efficiency of your air conditioner.

Dirty furnace air filters cause poor air quality in your home, put stress on your air conditioner, and dirty the ducts and system which may require professional cleaning. 

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(Source: Second Nature)

How to Check Your Furnace Air Filter

Air filters work during the season of allergies, wildfires, or flu season.

The nasty particles that may be riding in on your home’s air are dangerous, but your air filter can help.

Checking your air filter on your furnace is essential for your air conditioner and heating system’s safety.

The steps to check a furnace air filter are relatively easy and are listed below:

  1.  Turn off your furnace before inspecting the air filter.
  2.  Get access to wear the air of filter is installed, usually located in the ceiling or right on the furnace’s front panel.
  3.  Remove any screws or other fasteners to remove the metal grate that holds the filter in place.
  4.  Inspect the air filter for color, which can tell you if there is a build-up of dirt, common allergens, or other nasty air particles
  5.  Remove an air filter from your furnace if you witness any of the following:
    1.  A Visible black or brown circle that is the duct’s shape is a bad sign of a dirt filter. You can find this where the duct is sucking in the air from your home
    2.  Any tears or rips in the filter itself
    3.  The build-up of dust particles on the outside of the filter that is visible with the naked eye
    4.  A strong smell of smoke from the filter
    5.  Large particles attached to the outside of the filter that is visible with the naked eye

Once you get access to your furnace air filter and decide that it is dirty or damaged, you should replace it.

You are now one step closer to taking care of the air conditioner, which also uses the air intake from the furnace air filter.

Different Materials for Furnace Air Filters

There are several different types and materials for furnace filters.

It is essential to choose the type that fits your budget and the amount of filtration you will need in your home. 

Furnace filters come made of three main types of material: fiberglass, cotton, and polyester.


 Fiberglass is the least effective at creating quality air in your home. They are also the most common in homes.  They are generally all the same shape and about 1″ thick of woven fiberglass.


  •  Inexpensive 
  • Easy to install 
  •  Common and can be found almost anywhere for replacements.
  •  Will filter out dirt and dust


  •  Not great at improving the air quality in your home
  •  Will generally not filter out certain viruses and bacteria.
  •  Have to be replaced more often


Cotton is an excellent alternative to fiberglass because it is tightly structured. You can catch more of the bacteria, pollen, and viruses that fiberglass may not catch. It also is relatively common in department stores and hardware stores.


  •  Good at filtering out most allergens and dirt
  •  Is readily available at hardware stores
  •  Easy to install
  •  Can be cleaned and reused


  •  Have been known to Harbor bacteria and viruses or mold if not cleaned properly
  •  More expensive than fiberglass filters


 Pleated sheets of polyester can also come in washable designs like cotton. They are less common at hardware stores and tend to be a little bit more expensive.


  •  Self-charging material that can collect up to 10 times more particles than other filters
  •  Can come in varieties that are reusable if you clean them


  •  A little bit more expensive than other varieties of air filters
  •  Have been known to Harbor bacteria or viruses if not cleaned properly

These three main types of furnace air filters effectively keep your air conditioning system clean from dust that can put stress on the system.

Hopefully, this information will help you decide on what fits your budget and how often you want to change or clean your air filters for your furnace.

(Source: Brennan’s HVAC)

Hiring Professionals to Clean Your HVAC System

We’ve all been there before. You have neglected to change the air filter in the furnace because of other stress and obligations in your life.

However, now the smell of your air conditioner and your allergies are terrible.

Cleaning and HVAC system, especially your air conditioner after using it with a dirty air filter, is complicated. 

To properly clean the ducts, furnace, and air conditioning systems in a home, you need to have the right tools and expertise.

Ducks can be very long and winding in the home, so you need to have a flexible and long enough tool to clean the insides of these ducks properly. 

It would help if you also had to know how to open up and clean the vital components of your air conditioner intake and furnace intake, as well as the blower that pushes air out into your home. 

All of these cleaning requirements are difficult for those who do not have the necessary tools or expertise.

We will recommend that you find a suitable HVAC cleaner and get a quote on how much it will cost to clean your system.

After your system is clean, try to set a schedule for changing the air filter to maintain a clean doctor work furnace and air conditioner.

(Source: ABC Heating and Cooling)

The Steps of Replacing an Air Filter

Identifying a dirty air filter on your furnace is difficult enough. However, after identifying the air filter you will need to replace it.

Hiring a professional to take care of your furnace air filter may be the best option.

The following are the steps any professional will take in replacing your air filter:

  1.  Check your furnace air filter for damage or dirtiness.
  2.  Consult with you on the material for your furnace air filter.
  3.  Determine the dimensions of your furnace air filter exactly
  4.  Open up the grate or furnace covering to get access to the old dirty, or damaged furnace air filter
  5.  Use a flat-head screwdriver or your fingers to gently remove the dirty furnace air filter from the furnace’s opening or the air intake duct.
  6.  Use a cloth or damp rag to wipe the perimeter of the air filter gently. Also, take the time to wipe the great of any debris or dust that will go over the new air filter.
  7.  Gently push the new air filter into place with the top lettering facing out.
  8.  Close up the great that holds the air filter in place and fasten it tightly with a screwdriver
  9.  Turn your furnace on and ensure that the airflow through the air filter sounds and looks like it is working correctly.
  10.  If you hear any strange noises turn the furnace often immediately and inspect the installation of your furnace air filter

 As you can see, a change in the furnace air filter has quite a few steps involved.

This process should be done on occasion only and more consistently if it is high pollen or smokey time of year.

(Source: Home Depot)

The Benefits of Maintaining a Clean Furnace Air Filter for Your Air Conditioner 

Maintaining your HVAC system’s health and your air conditioner, in particular, is dependent on keeping your furnace air filter clean and replaced consistently.

The benefits of staying on top of the cleanliness of your furnace air filter include:

  •  Maintaining the quality of air in your home
  •  Reducing the cost of cleaning and repairs on your air conditioner
  •  Placing less stress on your air conditioning unit

Keeping the air filter on your furnace clean and replaced is an important proactive step for maintaining the air quality in your home and for prolonging the life of your air conditioner.

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