The air filters inside your HVAC system perform a critical function. No matter how clean a home may be, there will most likely be impurities in the air, such as dust or pet dander. Since we spend a large portion of our time indoors, it is important that we focus on the quality of our indoor air. Indoor air quality can be anywhere between two and five times more polluted than the air outdoors. If you have allergies, symptoms may become problematic, even if it is not allergy season.

Putting a new air filter inside your HVAC system becomes important once the old one cannot do its job. A dusty air filter can decrease indoor air quality and make your system work harder. There are some expenses associated with installing new air filters, but you should not look for shortcuts. Avoid reusing an old and dirty filter for these reasons.

1. High Energy Bills

Even though dirty and clogged air filters can cause many problems with the functionality of your HVAC system, they are often ignored. Dirty air filters can impede efficient operation by slowing down airflow, which means your house does not get cooled well. Your HVAC blower fan pumps air through the air filter continuously when your unit is running. A clogged filter makes the fan work harder to blow conditioned air. This process uses more electricity, which can significantly increase your utility bills over time. In addition, debris buildup can act as an insulator that disrupts the temperature transfer of the air flowing through the unit.

2. Poor Air Quality

The main purpose of an air filter inside your HVAC system is to serve as a screen that captures airborne particles. When your HVAC system is running, it gathers particulates such as dust, pollen, bacteria, dander, viruses, debris, and other allergens. As long as the air filter is clean, it keeps your indoor air quality in check. However, if the air filter is dirty and clogged, all those particulates may get circulated back into your home. Poor indoor air quality can affect your health, especially if you suffer from respiratory issues or allergies.

In addition, since air filters are usually not meant to be cleaned and reused (we’ll talk about an exception later on), it may be difficult to dry them off completely after washing them. Once your air filters become moist for an extended period, the small pores in the filter can become an ideal breeding ground for mold. Air is constantly being forced through your air filter when your AC is running. Thus, these mold spores can easily be detached from the filters and circulate throughout your home, which can lead to respiratory issues for you and your family.

Changing an air filter is a much healthier option than reusing an old one. Filters usually need to be changed once every 30 to 90 days, depending on the specific model that you are using. Running your HVAC system frequently or having multiple indoor pets living in your home can result in the need for more frequent filter changes.

3. Frozen Evaporator Coils

When your HVAC system is running, condensation builds up on the evaporator coils. In normal cases, this is not an issue because the cool air that runs throughout your system gets rid of that condensation with the process of evaporation. However, if your air filter gets clogged during the summer cooling season, there will be inadequate airflow to the evaporator coils. This causes the condensation to freeze. As a result, frost buildup on the fans or coils makes it complicated for your system to remove heat from the air and effectively cool your home.

For heat pump and air conditioning systems, a clogged air filter can also cause a buildup of dirt, bacteria, and mold. This buildup restricts the important heat exchange process, making your system unable to control the indoor climate effectively. This includes humidity control.

4. System Failure

Your HVAC system can be one of the most important investments you make in your home. It allows you and your family members to breathe healthy air while remaining comfortable. Apart from regular maintenance, regularly changing your air filters can play a vital role in extending the lifespan of your HVAC system by protecting interior components. Using old filters can result in the failure of the system, which may cost you thousands of dollars to repair or replace.

5. You Risk Damaging the Pleats

Air filters are very sophisticated and highly engineered, even though they may seem very simple. Their complex design allows them to catch as many particulates as possible, while allowing air to pass through and circulate inside your HVAC unit. Keep in mind that air filters are strong but lightweight.

A major issue that arises with reusing air filters is that you risk damaging their sophisticated structure. You are likely to damage the pleats as you try to clear the dust and debris off the filter. The pleat design plays a critical role in collecting dust from the air. This means that any damage could be detrimental to their capability of trapping dust, leaving your HVAC system and your health vulnerable.


An air filter is for single-use only. After 30 to 60 days, you will need to change it for a new one. The only exception here is reusable air filters. They are washable filters made out of durable materials that can be cleaned. Only certain HVAC models will utilize reusable filters.

Remember that you will run into similar problems if your reusable filters get clogged. If you select a reusable air filter based on the recommendation of a professional, ensure you follow the provided cleaning instructions. The frequency of cleanings will vary based off the specific model of filter that you’re using.

Keep an eye out for signs that your air filters need changing, such as higher energy bills that are slowly increasing over time, dust collection near the vents or on surfaces throughout your home, and an increase in allergy symptoms or illness. Ignoring these signs might cost you more money in the long run if HVAC malfunctions occur.

Call the Experts

If you are a resident of Gilbert or the surrounding areas, it’s imperative that your home has a clean air filter in your HVAC system. If you have questions about how frequently you should change your air filters, we here at A/C Doctors are here for you. We have a team of highly skilled technicians who are knowledgeable about all things heating and cooling. We can help you monitor your indoor air quality and provide you with expert advice. We can also perform routine and emergency plumbing services, including drain cleaning, plumbing repair, and leak detection. We offer both commercial and residential HVAC services. Give us a call at A/C Doctors to schedule an appointment.

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