How Often Should You Change Furnace Filters? How to Tell If the Filter Actually Needs Changing

How Often Should You Change Furnace Filters? How to Tell If the Filter Actually Needs Changing

Canadians know the value of a reliable and safe furnace during the long, cold winter months.

While most modern systems do not require extensive maintenance outside of regular professional tune-ups and cleanings, there is one critical component that every resident and business should pay close attention to: regularly changing the air filter that protects your furnace and indoor air quality.

But how often should you change your furnace filter? In the following discussion, Panda Home Comfort, Ontario’s leading HVAC experts, shares some professional advice to help your heating system run at its best through the cold season.

Why Is Changing Your Furnace Filter Important?

The filter that protects your furnace captures dust, dirt, and airborne particles before they circulate through your HVAC system. Trapping contaminants protects the interior components of your heating unit and ductwork while providing the best possible indoor air quality.

No matter how well-maintained any indoor space is, the air that enters our living spaces contains untold numbers of these airborne particles. This means that every filtration system is constantly absorbing these contaminants and will eventually become clogged with trapped material.

The resulting restriction in airflow places excess pressure on your system, ramping up energy consumption while reducing system efficiency. The added wear and tear increases the risk of malfunctions and expensive repairs while shortening the expected lifespan of your system.

How Often Should You Change Your Furnace Filter?

Knowing when to change a furnace filter depends on several factors — the type of filter, the structure and size of your living space, and how frequently you use your furnace.

It’s important to know the type of filter your furnace uses to consider a proper replacement schedule:

  • Standard one- to two-inch filters. Change the most common-sized filters every 30 to 90 months. However, if you have indoor pets, live in an area with poor outdoor air quality, or have any allergy sufferers in your home, we recommend changing the filter every 30 days.
  • Three- to four-inch filters. These medium-sized filters can last six to nine months, but we recommend you check them every month to make sure they haven’t clogged up prematurely.
  • Five- to six-inch filters. High-efficiency HVAC systems sometimes use larger filters that can last up to 12 months.

Because of the excess demands that winter weather presents, we recommend checking your filter monthly, regardless of its size or design, during cold weather.

Types of Furnace Filters and How Long They Last

Knowing when to replace a furnace filter also depends on its design. There are different types of furnace filters, and each provides varying lifespans and filtration capabilities. These are the options most commonly found in Ontario:

  • Fiberglass filters. These are inexpensive, but offer minimal filtration. They typically last around 30 days during the heating season, and you should expect to replace them monthly.
  • Pleated filters. These mid-range filters offer better filtration and can last from three to six months depending on usage and environmental factors.
  • HEPA filters. High-efficiency particulate air (HEPA) filters can capture up to 99.97% of airborne particles and can last up to 12 months. However, these filters often require special HVAC equipment and may demand professional installation.

How long do furnace filters last? It’s critical that you understand the manufacturer’s guidelines and recommendations for the specific design you use in your home.

Factors That Affect Filter Longevity

Of course, while the basics of filter size form general guidelines, other important considerations impact the answer to, “How often should you change your furnace filter?”

Be especially vigilant in regularly inspecting your filter if your indoor space involves any of these factors:

  • Pets. Pet fur and dander immediately become airborne and can rapidly accumulate in your furnace filter.
  • Allergies. Poor filter performance leads to higher particle counts of dust and allergens. If anyone in your household has allergy sensitivities, change your filter more often.
  • Environmental issues. Homes in dusty or urban areas often require more frequent filter changes due to increased airborne pollutants.
  • Extensive system usage. If your HVAC system runs continuously, particularly in extreme temperatures, the filter will accumulate debris faster.

How To Tell If a Furnace Filter Needs Changing

How often should you change your furnace filter? It’s not always obvious when performing regular checks, but there are some clear signs that your filter needs replacing:

  • Visible dirt and debris. Pull the filter out and take a close look at it for discoloration or visible debris. If you can’t see light passing through it, it’s time for a replacement.
  • Reduced airflow. Does your home feel colder than normal or are you noticing weak airflow from your system’s vents? Clogged filters are the leading cause of restricted circulation.
  • Higher energy bills. Clogged filters cause excess system stress, driving energy consumption up.
  • Increased allergy symptoms. If anyone in your home begins experiencing more frequent cold-weather allergy symptoms, your furnace filter may be allowing allergens and dust to recirculate through your living space.
  • Dusty home. If you notice dust building up faster than normal, it’s a strong indication that your furnace filter has lost effectiveness.

These indicators should serve as useful markers to determine how to tell if a furnace filter needs changing before your air quality or HVAC performance decreases.

What Happens If You Don’t Change Your Furnace Filter?

Clogged filters are a primary cause of heating system issues. They cause multiple problems, including:

  • Decreased efficiency. Every HVAC system depends on unrestricted airflow to operate properly. Dirty air filters lead to system stress and lowered energy efficiency. You’ll pay more for energy while experiencing poor performance.
  • Increased wear and tear. System overwork is often the direct cause of component failure and breakdowns. This leads to system outages, expensive repairs, and shortened HVAC lifespan.
  • Poor air quality. Dirty filters are unable to properly capture airborne pollutants and allergens. This leads to poor indoor air quality, excessive dust, and health concerns.

How To Change an Air Filter in a Furnace

Most property owners can handle the straightforward task of inspecting and changing a furnace air filter.

Here’s how to change an air filter in a furnace:

  • Turn off the furnace. For safety, turn the furnace off at the thermostat before replacing the filter.
  • Find the filter compartment. Find the filter behind the large air duct for returning air.
  • Take out the dirty filter. Take out the existing filter and check the airflow arrows on the filter.
  • Correctly install the new filter. Make sure the arrows on the new filter point toward the furnace, as this indicates proper airflow direction.
  • Close the compartment. Securely close the filter compartment. Switch the thermostat back.

Regular filter inspections and changes are the best preventative care to supplement regular professional system inspections and tune-ups.

Work With the Professionals at Panda Home Comfort for Optimal Heating Performance

Just knowing how often should you change your furnace filter is the first step toward handling routine self-maintenance for your heating and HVAC system. When it comes to routine professional maintenance, trust Panda Home Comfort.

Make filter maintenance a priority to keep your system efficient and your home healthy! When you need assistance with any HVAC and indoor comfort needs, contact the friendly experts at Panda Home Comfort at +1 416-877-8260 for more information.