How Often to Change HVAC Filters

Jul 15, 2021 | Types of HVAC Filter

If you’re asking how often to change HVAC filters, the answer depends on the system, brand, unit maintenance schedule, and the characteristics of your home. Why not call Shriver Mechanical as a trusted HVAC company for expert advice and professional indoor air quality services?

Do you know how often to change HVAC filters at your home or office? You might be surprised to learn that even the Shriver Mechanical team cannot provide a standard answer that applies to all settings, but certain factors make a difference. The efficiency and lifespan of the air conditioning or furnace filter are most affected by this decision, and it is best to reach out to professionals like Shriver Mechanical for clarity on your particular unit.

How Often to Change HVAC Filters for Long-lasting Results

Most air filter manufacturers and brands include a recommendation for how frequently to change the filters of your specific HVAC unit. You can find the information on the product box or manual that comes with every new filter. General recommendations include:

  • 1-inch and 2-inch filters: frequent replacement or every three months
  • 3-inch and 4-inch filters: replacement every six or nine months
  • 5-inch and 6-inch filters: annual replacement 

Other Factors Affecting HVAC Filter changes

The manufacturer’s recommendation is not the only factor that you should consider. Deciding how often to change HVAC filter types depends on your unit’s performance and efficiency, including whether you have pets, how you use the system, and if your home’s residents suffer from allergies.  


Many pets shed dander and hair that become airborne. It clogs filters fast, so we recommend changing the HVAC filter every two months if you have pets. Families with two or more animals may need to replace the filter every month.

System Use

How frequently your HVAC system is in use affects a filter’s lifespan significantly. When the heating or cooling unit runs often, indoor air circulates more and may trap contaminants, dust, and debris. During high-use periods, the filters fill up faster, and you will need to change them frequently. 



Clean air at home is essential for your health. If you or your children have allergies, you will need to change the HVAC filters more often to ensure comfort and cleanliness.


Signs You Need to Change Your HVAC Filter

If you forget to change your HVAC filter, you may notice some worrying signs emerging around your home. Call our professionals for advice and assistance as soon as you notice any of the following hints that you need to replace your filters:

  • The air isn’t hot or cold enough  
  • The heating unit is cold, or the air conditioner is too hot  
  • An electricity bill spike
  • An increase in allergies or hay fever attacks
  • More dust near the vents 

 Estimating how often to change HVAC filters is tricky because of the many different factors at play, but Shriver Mechanical can help. Our certified HVAC technicians will help you determine whether your filter issues need our professional attention and ensure your units are running smoothly throughout the year. Contact Shriver Mechanical today at 770-975-1927 to schedule regular maintenance and HVAC filter replacement.