What Is An Air Filter?

You may not give your HVAC system much thought (unless it’s not working!). Your HVAC keeps air moving through your house – warm air in the winter months (your heat) and cold air in the summer months (your air conditioning).

All that air moving through your house is filled with dust, dirt, and debris. Pet dander, pollen, dead skin cells, and many other things that float through your air and can be circulated throughout your home.

An air filter, however, does exactly what the name says – it filters out the particles in the air so they are not circulated throughout your home when your HVAC system is running. They clean the air as it moves through your vents so you have cleaner, fresher air to breathe. This has other benefits such as less dust in your home (cleaner home!) and prevention against allergies being triggered from pollen in the air.

How Often Do I Need to Change It?

As with everything in life, the answer is: it depends.

There are many types of air filters on the market. Higher end filters tend to need changed less. The number of people you have in your home, the number of pets in your home, the size of your living space, and the amount of time you run your HVAC system all have an impact on the frequency that an air filter needs changed. You may even choose to change your air filter more regularly if you have a child or an older family member in your home or someone with breathing conditions. It can get complicated!

At Reliance Heating and Air Conditioning, we want to provide some general guidance for you to follow. As always, we recommend contacting us if you have any specific questions about your particular system or setup.

In southeastern Pennsylvania, we recommend changing your air filter at least once every six months.

Because southeastern Pennsylvania has four distinct seasons, fall and spring tend to see far less usage of a home’s HVAC system which can extend the lifespan of your air filters. But, we do see a considerable amount of pollen in the air which can increase the strain on an air filter.

Again, these factors are going to differ for every home. There are too many factors for there to be a “one-size-fits-all” recommendation. Some good news – if you subscribe to Reliance’s maintenance plans, you don’t have to think about this at all – we will take care of this for you!


Regular maintenance of your HVAC system can seem daunting. But replacing your air filter is a straightforward task that can increase the health of the air in your home and the longevity and life of your HVAC system.

Contact Reliance today for all your heating and air conditioning needs!