HVAC Air Filters

A common question we have been asked recently is how frequently HVAC air filters need to be changed. This is due to the recent air pollution from the Canadian forest fires and the lack of rain during allergy season. To help answer this question, we have to start by explaining the basics of HVAC air filters.

Air Filters 101

For starters, what is a HVAC air filter? A HVAC air filter, like the lint trap in your dryer, is a filter that collects dust, dirt and other microscopic particles that are circulating in your home’s air. When you turn on your heating or air conditioning system, the air filter collects the dirt and dust particles to help protect your HVAC system and to clean the air in your home. Once the air filter becomes too full of dust and dirt, your HVAC unit needs to work harder to keep the air flowing throughout your system which results in your monthly energy bills increasing.


There are three main types of air filters:



  • 1” Standard Air Filter
  • 4” Media Filter
  • Electronic Air Cleaner (EAC)


While all these filters essentially serve the same purpose, the maintenance required for each varies. Please see below for our recommendations on how frequently you should change or clean your HVAC air filters:


  • 1” Standard Air Filter: We recommend checking and changing these air filters once a month. Occasionally these air filters can last up to 90 days.
  • 4” Media Filter: We recommend checking and changing these air filters every six months. One time at the beginning of the air conditioning season, and one time at the beginning of the heat season.
  • Electronic Air Cleaner (EAC): We recommend checking and cleaning EACs every six months. One time at the beginning of the air conditioning season, and one time at the beginning of the heat season.


There are certain scenarios that can factor into how frequently you have to change or clean your HVAC air filters. This list includes, but is not limited to:


  • Pets living in the house
  • Number of people residing in the house
  • Smokers living in the house
  • Living in an area with large amounts of pollen bearing trees
  • Allergy sufferers living in the house

How to Change Air Filters

Furthermore, it is important to understand how to change the HVAC air filters in your system. In newer air conditioning and heating systems, the air filters are located close to the blower motor. To change an air filter:



  1. Locate the air filter in your HVAC system
  2. Remove the box or cover holding the air filter into place
  3. Take out the dirty air filter
  4. Discard the dirty air filter in a trash can or trash bag to contain the dirt and dust
  5. Take new air filter out of packaging
  6. Insert new air filter with the air flow arrow pointing towards the blower motor


It is critical to write down the date that the air filter was changed or cleaned so you know when to change or clean it next. A simple way to remember this date is to set a reminder in your calendar on the 1st of every month to “Check or Replace Your Air Filter”. For 4” Media Filters or EACs, we recommend setting a reminder every 4-6 months on the 1st of the month. Another helpful trick is to write the date the air filter was installed or cleaned on the side of the new air filter before putting it in the HVAC system.


Changing or cleaning your HVAC air filters on a regular basis is an important part of maintaining your HVAC system. Not only does a clean air filter help reduce the energy it takes to run your HVAC system, but it also improves the indoor air quality as well. Our technicians change the air filters when we come out to perform our bi-annual cleanings of your air conditioning and heating systems. If you have not had your HVAC system cleaned yet this season, please call our office at 610-642-6323 to get on our calendar or visit us on our website at www.bobsredtrucks.com.

CPR, AED & First Aid Training with Bobs Red Trucks

March 24, 2023
At Bob Cermignano Air Conditioning & Heating, Inc., we value our employees and believe in the importance of education. While our technicians continually take technical courses to further their knowledge and experience in the HVAC industry, we enrolled all our employees in a different type of training this past week- t he American Heart Association’s Heartsaver ® First Aid/CPR/ AED Course. This two-part course was held exclusively for our company at the Merion Fire Company and was taught by an American Heart Association certified instructor from Narberth Ambulance. The first part of the course focused on CPR and AED while the second part focused on First Aid. The overall topics we covered in this course were: First Aid Medical Emergencies Injury Emergencies Environmental Emergencies Preventing Illness and Injury Adult, Children and Infant CPR and AED Use Opioid- Associated Life-Threatening Emergencies Whether working in the field or volunteering as a baseball coach after business hours, we wanted to provide our employees with the knowledge and skills to help save a life if they ever find themselves in an emergency.  Below is an overview of what our employees learned over the two-part course.

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October 14, 2021
You’re in the market for new HVAC equipment. However, you’re overwhelmed with all of the choices and are unsure of what to expect throughout the installation process. Not only is this a tough decision but also an expensive investment. At Bob Cermignano Air Conditioning & Heating, Inc., we make the HVAC installation process as easy as possible from start to finish. 

Bryant® Certifications and Services

February 19, 2021
Over the years, Bryant® has awarded our company with several distinguished certifications and services. The list of certifications and services includes: Factory Authorized Dealer Financing Available with Approved Credit Indoor Air Quality Specialist NATE® Certified Ductless Systems

Tech Tip of the Month- How to Read Energy Guide Labels

February 3, 2021
It is important to learn how to read Energy Guide Labels when in the market for new home appliances. Energy Guide Labels show the annual energy consumption and average operation costs for each appliance. They also reflect an appliance’s energy efficiency range. The more efficient the unit is, the cheaper it will be to operate it. The Federal Trade Commission (FTC) requires manufacturers to put these yellow and black labels on most, but not all, new appliances. For HVAC equipment, you will find Energy Guide Labels on the following products: Central Air Conditioners Boilers Furnaces Heat Pumps Water Heaters Room Air Conditioners

HVAC Rating Acronyms Explained

January 22, 2021
MERV, SEER, AFUE and HSPF. You’ve heard of these terms before, but do you know what these HVAC rating acronyms mean? The experts at Bob Cermignano Air Conditioning & Heating, Inc. define and explain each acronym below. 

Tech Tip of the Month- Emergency HVAC Service

January 7, 2021
Unfortunately, we cannot control when our heating and cooling systems stop working or break down. However, if you require emergency service after business hours, Bob Cermignano Air Conditioning & Heating, Inc. offers 24/7 HVAC service. 

Tech Tip of the Month- How to Winterize Your HVAC System

December 15, 2020
The Philadelphia area may have its first significant snowstorm this week in more than 652 days . As we prepare for the impending storm, we want to share a few tips on how to winterize your HVAC system. 

Tech Tip of the Month- Heating Seasonal Maintenance

October 27, 2020
Having heating seasonal maintenance each fall helps maintain the efficiency and effectiveness of your HVAC system. With our Energy Savings Agreements, we provide a complete cleaning and inspection of your heating system. Therefore, regular maintenance of your HVAC system will:  Provide longer lasting equipment Reduce utility bills Reduce repairs Provide a more comfortable indoor environment Protect your investment
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