How long has it been since you last thought of your air filter, much less changed it? 30 days? 100 days? More? Your filter aims to catch airborne particles and therefore clean your air. And yes, your filter DOES do this, but it is not the primary function of air filters. Air filters are meant to trap airborne contaminants to keep them out of your heating and cooling system. However, because the filter removes impurities for the benefit of the system, your air quality benefits as well. 

Because it is trapping these contaminants, your air filter can get pretty nasty pretty quick. The prevailing assumption is that your home’s air filter should be replaced every three months, but is that truly how often you need to change your filter, and what happens if it hasn’t been changed? Let’s first look at what factors may help determine the life of your filter, then at several signs that mean your air filter may need to be changed right away.

Factors to Consider When Determining How Often to Change Filters

So while the typical recommendation for changing your filter is about three months (or ninety days), you may have to change them more or less often due to several other factors. These may include: 


  • Size and Thickness of Filters: The larger and thicker the filter, the less often you will have to change it. This result is because there is more space to catch the contaminants, meaning more allowance for accumulation before the amount becomes too much for the filter.
  • Type of Filter: Fiberglass air filters and pleated air filters are the two major types of filters available. Although both varieties are disposable, they have a few key differences. Fiberglass air filters are less expensive than metal air filters but are less effective in capturing dust and particles in the air and should be replaced every 30 days or fewer. Pleated air filters are more expensive at first, but they are more effective at catching particles and can last for 90 days.
  • Pets: Many people enjoy having pets in their homes, but our four-legged family members do have an impact on indoor air quality, especially those with fur. They track in dirt, pollen, mildew, and other toxins from outside and can release pet hair and dander into the air. Check your air filter once a month if you have one or more furry pets, and replace it when it becomes unclean.
  • House Size: Your air conditioners and furnaces will have to pump less air for the same amount of temperature change if you live in a “smaller home,” which could mean fewer filter changes. However, if you have a smaller portable or room-sized air conditioners or furnaces, you may find yourself changing filters more often as they often come with smaller filters due to their size.
  • Season: If you live in a mild area and just use your air conditioner or furnace for a few hours a day, one filter could last quite a while, as long as a season or even a year in some cases. On the other hand, if you use your HVAC system regularly, such as in the Spring or Summer when it is hotter or more allergens are in the air, you’ll need to change the filter every few weeks (especially if you are using fiberglass filters).
  • Air Quality and Allergens: The quality of the air outside can have a significant impact on how often your air filter needs to be changed. If you reside in a big city, pollutants like smoking, dust, and other debris will sneak into your home and clog your air filter faster. Allergens in the air can also fill up your filters pretty quickly. If you have allergies, utilizing a high-quality air filter and replacing it more frequently can help to alleviate your symptoms.


Signs You Need to Change Your Air Filter

So what should you be on the lookout for when it comes to signs you should change your air filter? Here are six quick and easy ways to know when you should go ahead and pull that filter out and replace it with a new one.

  • Are you experiencing a surge in allergy symptoms such as coughing, running eyes, and sneezing? Allergens may have filled up your air filter, and changing it out may be a quick and easy way to help alleviate some symptoms.
  • Take out your air filter. If you cannot see through it, or it appears visibly clogged, then it is past time to replace it!
  • If you touch your air conditioning unit and it feels hot, change out that filter! It is probably clogged and making your unit work overtime to keep pushing air through.
  • Additionally, if you aren’t feeling that the air being pushed through your home is as cold as it should be, take a look at your filter. Cool air has a more challenging time moving through a clogged filter and can be easily remedied by exchanging what you currently have in place.
  • A dusty atmosphere is one last good sign that your filters are clogged. The filter, when performing correctly, should take care of a lot of that dust, so any accumulation means it is not working at full strength and should be swapped out.

You’re not alone if you forget to change your air filter regularly. Daily life is hectic enough on its own, and many homeowners overlook this basic maintenance task. As seen above, a number of factors determine the frequency with which you should change your air filter. While typically, an air filter should be replaced every three months, you’ll probably need to change it more frequently if you have pets or suffer from allergies. Other times you might not have to change it as often, it all depends on the varying circumstances of your home or business.

Needing some peace of mind when it comes to your HVAC system? 4 Seasons Home Comfort can do cleanings and inspections for you with our Certified HVAC technicians. You can also book annual seasonal inspections and maintenance with 4 Seasons Home Comfort on an ongoing basis, so we will contact you when it’s time to look after these home units that work so hard looking after you! Contact 4 Seasons Home Comfort for service you can count on or visit our showroom at 3620 9th Ave North in Lethbridge.