How to Know if My Air Filters Need to be Changed?

by | Sep 20, 2019 | AC Maintenance

Your HVAC’s air filters may seem like nothing more than a pleated fiberglass material enclosed in a cardboard frame. In reality, though, air filters play a critical component in your AC as they are responsible for filtering the air circulating in the system. As well, they also keep larger particles from entering the system thus protecting it from damage. Because of their role, air filters get dirty pretty quickly and need to be regularly changed. Otherwise, dirty ones will affect indoor comfort and the AC’s performance and that is why it is very important to know when to change them. Experienced air conditioning companies explain the typical signs to look for so you know when your air filters need to be changed:

Poor Indoor Air Quality

Poor indoor air quality is a top sign that the filter needs to be changed. A dirty air filter essentially fills your home with dirty, unhealthy air. If you or other household members notice allergy flare-ups, more headaches than usual, sore throats, and/or congestion, check your air filters.


Strange Noises

Every machine makes some noise, and the HVAC is not an exception. The AC system may produce a clicking sound when starting then quietly hum as it runs. While this is perfectly normal, if you hear high-pitched buzzing noises, squealing or squeaking sounds, something is amiss. Different noises indicate different problems, but squealing sounds, in particular, could mean that air is struggling to move through the filters because they’re so clogged. The noise comes as the blower struggles to circulate the air. The squealing sound may also be combined with hot air coming from the AC. This is an indication that the blower is overheating and all these points to one problem – dirty air filters that need to be changed.


A Skyrocketing Energy Bill

As dust and debris in the filter hinder the free flow of air, your AC has to work harder to perform. An overworked furnace, aside from producing lackluster heating and cooling results, also causes a huge uptick in your energy bills. As the system works harder and longer than usual, it consumes more electricity. In most households in Canada, heating and cooling already take up at least half the cost of one’s energy bill.  According to the Department of Energy, dirty filters raise an AC system’s energy consumption by 15 percent.


Duration of Service

You don’t need to wait for the above signs to change your air filters. Most filters need to be changed every one to three months. Of course, the frequency depends on the MERV ratings, quality of the HVAC, and characteristics of your household. However even with these specifications, if you have more indoor pollutants, your air filters will get dirty faster thus needing more frequent changing. For instance, if you keep pets and have household members who are prone to allergies, you should change the air filters more often than is recommended in the manufacturer’s specifications.


One best practice is conducting regular inspections of your HVAC. Your eyes will not deceive you – so if your air filters look dirty, then they are dirty and you should change them. Ignoring these signs will eventually lead to the complete HVAC breakdown leaving you with no other choice but to replace the entire system – a costly affair you can avoid by being more attentive and prompt in action.


About The Author

John Magninat

John Magninat

Owner John Magninat is a third generation air conditioning repair man. Classic Services Air Conditioning & Heating is a family company with family values and our customers are our top priority.

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