When Should I Change My Air Conditioner's Air Filter at Home?

February 26, 2015

Want the fast answer? Read our FAQ on "How often to change the air filter".

Sometimes we’re asked what is the most important thing that Winnipeg area homeowner's can do to protect their air conditioning and heating system between their regular tune-ups? It's a simple question with a simple answer; remember to change the heating and air conditioning air filter. Buying new furnace and return air filters is critical to the ideal operation of your HVAC system, not to mention your home's air quality. Research suggests that indoor air pollution is among the top five environmental health risks? We know it's the last thing on your mind, but this is really important stuff. Changing the air filters is not all that hard for most Winnipeg homeowners, but there are typically two hurdles to actually accomplishing this task:

Determining just how often to swap out your furnace or air conditioner filter.
Remembering to change air filters when needed.

When To Change Your Air Filters

Most filters have a printed "expiration" date on the box or plastic. It may instruct "Lasts up to 3 months" or "Change filter every 90 days". Check out the filters at the store and you'll notice that some are engineered to only last one month, while other manufacturers (like Honeywell) have released media air cleaners with filters meant to be exchanged once every 6-12 months. The industry standard seems to be once every three months for most higher quality filters, but we have a rule of thumb that we tell our friends, and family to go by. If it's dirty, change it! A dirty air filter can contribute or cause damage to pricey parts, like your compressor, so it's best to change it out more often than not. If you want to stick to the manufacturer's recommended limit, we suggest writing the date on the filter when you swap it out, and adding a reminder for yourself in your phone or on a calendar. Also note that your filter manufacturer may have a different recommendation from your HVAC system manufacturer.

Determining how often to change your air filters hinges on several factors:

Type of filter your A/C system requires
The overall air quality of your Winnipeg area home
Pets – Dogs, cats, etc.
Number of occupants in the house
How much construction is taking place in the neighborhood around your home

For your typical 1"-3" air filters, the manufacturers basically tell you to change them every 30-60 days, which is really a great rule of thumb. But general rules aren't always for everybody. If you put up with light to moderate allergies, you might need to upgrade your air filter or change them even more regularly than OEM specifications. On the other hand, if you're in a remote area, own a seldom occupied home (like a vacation home) or an area where there are fewer cars around, changing your air filter every 12-months may be quite sufficient. Why do we call out our beloved pets? They have a tendency to shed, which can clog your air filter in no time, just like a vacuum. Of course, the air filter is just doing its job by capturing pet hair and dander, but extremely dirty filters can cause seriously reduced HVAC performance.

In summary:

Seldom used home or single occupant homes without pets or allergies: Change 6-12 months
Common suburban home without pets: Change every 90 days
House with a pet: Change every 60 days
More than one pet or have allergies: Change every 30-45 days

How To Remember To Change Your Air Conditioner's Air Filters

It's simple; sign up for the Service Experts Email Club. When you do, you can elect to receive (or not) great email coupons and newsletters with a lot of tips and discounts on AC repairs and tune-ups. But wait… there’s more, your email subscription preferences let’s you set a reminder to change your Winnipeg area home's air filter every 30, 60, 90, 120 or 365 days, or the date of your choosing.

How to replace your return air filter

Most of you know how to replace the air filter in their equipment, but some residences have an extra filter in the return vent. Whether you have one or not is dependent on which HVAC system you have. Your unit is made to handle a set amount of pressure in your house, and the more filters you have the more the blower motor works, which can reduce the life expectancy of your system if it isn't designed for it. Learning whether you have a return filter and replacing it is simple:

Go to your return air vents.
Some covers have screws and some have tabs. Unscrew or pull tabs to take off the wall.
Look for a filter. If one is in place, pull it out and write down the size.
Verify the filter type is the one recommended by the manufacturer.
If filter is dirty, replace with the manufacturer's recommended filter of the same size and type.

Crazy as it may seem, filters can greatly affect your home's airflow, which is why we recommend checking in with the manufacturer. A top tier HEPA filter that is designed to catch tinier debris will reduce airflow more than a cheaper filter. With restricted airflow comes greater pressure on your system, so you ought to verify that your HVAC system was made to handle it. Otherwise, you might experience reduced heating and cooling efficiency in your home, and unit parts may die off much faster than otherwise.

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