Where is The Air Filter Located in The Furnace?

How often to change furnace filterThe air filter is an integral part of any furnace’s HVAC system. Its job is to remove dust, dirt, and other particles from the air, helping to keep the air quality inside your home clean and healthy. A dirty or clogged filter can negatively impact indoor air quality, and your furnace’s energy efficiency, so replacing or cleaning it regularly is vital. But where is the air filter located in the furnace?

The air filter’s location can vary depending on the furnace’s make and model, making it challenging to locate. However, knowing its location is crucial for maintaining optimal indoor air quality in your home.

This article will also provide additional information about air filters, their importance, and how regularly replacing them can improve your furnace’s overall energy efficiency. So, buckle up and read on to learn more about air filters in furnaces.


Where is The Air Filter Located in The Furnace?

The air filter’s location depends on the type of furnace you have. In most cases, the air filter is located in the furnace’s return air duct or grille. This ductwork is responsible for drawing air from the rooms in your home and returning it to the furnace for heating. The air filter in the return air duct can trap dust, dirt, and other debris before the air circulates back into your home.

Step-by-Step Instructions for Locating the Air Filter

Following the steps to locate the air filter in your furnace is easy. Here is a step-by-step guide to help you find the air filter:

  1. Locate your furnace: The furnace is typically in your basement, attic, or closet.
  2. Turn off your furnace: Before you open the furnace panel, turn off your furnace to prevent any mishaps.
  3. Remove the access panel: The access panel is on the front of the furnace. Carefully remove the panel and set it aside.
  4. Locate the air filter: Once the access panel is removed, look for the air filter. If it’s a disposable filter, it should be visible inside the furnace compartment. If it’s a permanent filter, it may be located inside the return air duct.

Why is It Important to Change the Air Filter Regularly?

Regularly changing the air filter in your furnace is crucial for its efficient operation and healthy indoor air quality. Here are some reasons why:

Improves Air Quality: The air filter traps dust, dirt, and other particles, preventing them from circulating in your home. A clogged or dirty filter can reduce the air quality, leading to allergic reactions and respiratory problems, especially for people with asthma or allergies.

Increases Energy Efficiency: Dirty or clogged air filters can cause your furnace to work harder and consume more energy, leading to higher energy bills. Replacing or cleaning the air filter can help reduce your furnace’s energy consumption and save you money on utility bills.

Extends Furnace Lifespan: A clogged or dirty air filter puts extra strain on your furnace, reducing its lifespan. Regular air filter replacement or cleaning can help your furnace work efficiently and extend its lifespan.

When Should You Change the Air Filter?

The general guideline is to change the air filter at least every three months or every 30-60 days if you have pets or allergies. Still, several factors may require more frequent filter changes, such as dirty filters or clogged air ducts. Generally, it’s best to check the filter monthly and ensure it’s still clean and functioning correctly.

Factors that Influence the Frequency of Air Filter Changes

Changing the air filter regularly is essential for the efficient operation of your furnace and healthy indoor air quality. However, the frequency of air filter changes can vary depending on several factors.

  • Type of filter: Different types of filters have varying lifespans. For example, disposable filters must be replaced every 1-3 months, while permanent filters can last up to six months or even longer.
  • The number of occupants: More people in the home mean more air circulation and higher indoor air quality concerns, which require changing the air filter more frequently.
  • Pets: If you have pets, especially those with long hair, your air filter may clog faster, and cleaning or replacement will be required more frequently.
  • Home location: Homes located in areas with high pollution or dust levels require more frequent filter changes.

Signs That Indicate It’s Time to Change the Air Filter

Several signs indicate it’s time to change your air filter, including:

  • Visible dirt: If you can see dirt on the filter, it’s time to change it.
  • Reduced airflow: If you feel that there is reduced airflow from your HVAC system and weak heating or cooling performance, it may be time to change your filter.
  • Unpleasant odours: A dirty filter can cause unpleasant odours to circulate in your home, indicating it’s time to change it.
  • Increased allergies or breathing problems: A clogged filter can lead to poor indoor air quality and cause respiratory problems or allergies.

How to Maintain the Air Filter?

Here are some tips on how to maintain your air filter to ensure it’s working correctly:

Buy the Correct Size and Type of Filter

Buying the correct size and type of filter is crucial for optimal furnace operation and indoor air quality. Using the wrong size or type of filter can lead to reduced airflow and poor indoor air quality. Ensure you check your furnace’s manual for the correct filter size and type, or check the current filter to match it to the correct type if unsure. Choosing the correct filter can improve your furnace’s energy efficiency and reduce the frequency of filter maintenance.

Install the Filter Correctly

Ensure you install the filter correctly, following the manufacturer’s instructions for your furnace model.

Check the Filter Monthly

Check the filter monthly to ensure that it’s clean and functioning correctly. Consider setting a reminder to check your filter using your phone or calendar application.


The air filter is located in the return air duct of your HVAC system and helps protect the system from dirt and debris. Regularly changing or cleaning your air filter is essential for optimal furnace operation, healthy indoor air quality, and efficient energy usage. Consider checking the filter every month and replacing it when necessary. Doing so will help maintain your furnace’s lifespan, reduce energy costs, and improve indoor air quality.