When Should I Change My HVAC Air Filter?

San Rafael

(415) 942-6565

Santa Rosa

(707) 452-3464

An HVAC air filter is an engineered filter used in heating, ventilation, and air conditioning systems. The HVAC air filter aims to trap and remove dust, pollen, mold spores, and other contaminants from the air flowing through the system. Most people don’t think about them until they start noticing a foul smell or find themselves sneezing and coughing a lot, but it is essential to replace HVAC filters regularly. It’s advisable to get a nearby furnace repair expert involved if you notice any potential issues with an HVAC system.

Why Change Your HVAC Air Filter?

To understand when you should change your HVAC filter, you first need to know why it’s crucial to change it. So, here are some reasons why an HVAC air filter is required in the first place:

Increase the Life of Your HVAC Unit

If your HVAC unit has a dirty air filter, it can reduce airflow into your home or office, leading to overheating and damaging the unit. A clogged air filter can also cause a backup of moist, heated air into your building, which causes mold growth and dust mites. You should inspect your furnace filter for any damage or wear and get it replaced by a furnace repair technician near you if necessary. Timely replacing your air filters will extend the lifespan of your HVAC system beyond 10-12 years.

Improve Indoor Air Quality

An air filter removes airborne pollutants from the air supplied to your home or office. It also traps pollutants near (and inside) your building, which can be harmful to people with respiratory problems like asthma or allergies. A dirty HVAC filter prevents fresh air from entering your home or office. Plus, a clogged or dirty filter doesn’t work well at filtering out particles, leading directly to poor indoor air quality.

Save Money

An efficient unit with a clean HVAC air filter can save you up to 30 percent money on your utility bills.

Improves Efficiency and Performance 

Many of these particles are just small pieces of dirt, dust, and other debris, which can get trapped in the coils, ducts, and casings within your HVAC system. So, if your air filter is not working as it should be, it can reduce your HVAC unit’s efficiency and performance over time.

Factors to Consider When Changing Your HVAC Air Filters

Changing your HVAC air filter too often can be a waste of money, but not replacing it often enough leads to poor indoor air quality and potentially severe health problems. Here are some factors that will determine when you should change your HVAC air filters.

Home Size

One of the most fundamental factors you should think about when determining how frequently you need to change your HVAC air filters is the size of your home. The larger a home is, the more difficult it can be to circulate clean, fresh air throughout all areas. So, if you live in a larger home, keep your HVAC system clean by changing out filters regularly and maintaining it with the help of a furnace repair expert.

Location/Air Quality

Another weighty factor in deciding when to change your air filter is where you live. The air we breathe comes from outside of our homes and contains microscopic particles that can be harmful to us if they are not removed.

Changing your air filters more frequently might be necessary if you live in an area where there is a lot of pollution and dust in the air, like those closer to construction sites. However, if you live close to an area with less dust in the air and no major sources of pollution in the area, then changing your filters every three months might be enough.

Quality of Air Filter

If you purchase a high-quality air filter, it may last at least six months to a year before needing to be replaced. However, the frequency of when the filter needs to be replaced will depend on several factors – how many people live in your home and if anyone smokes or has allergies. A professional furnace repair expert near you can help you find the air filter that fits your needs.

Type of Air Filter

Another essential factor to consider is what type of air filter you have and how air flows through your HVAC system. If your home has a large open floor plan with high ceilings and large windows, you will need to change your filter more frequently as it will be exposed to more airborne particles.

Young Children

If you have kids in your home, you may need to change your air filter every 2 to 3 months. In addition, you should consider getting your HVAC system maintained by a professional furnace repair expert near you once a year.

House Pets 

Dogs, cats, and other animals shed hair and dander into the air that can clog up your air filter. So, if you have furry friends running around, you might need to replace yours every 2-3 months.


If you or a household member has allergies or asthma, you’ve probably heard the advice to change your HVAC air filter once a month. That’s because constantly circulating dirty air can worsen allergies and cause breathing problems for people with asthma. You may even be wise in purchasing a higher-quality air filter that can hold up under these conditions for more extended periods of time.

How To Tell When It’s Time for a New Air Filter?

Inspect your air filter and contact a professional furnace repair expert near you to perform HVAC maintenance work if:

  • You start noticing a drop in comfort
  • Your furnace makes loud noises when it’s on
  • There’s an inconsistent cooling or heating
  • The air quality has dropped
  • You notice debris inside your unit compartment
  • The air filter is damaged or worn out
  • Your HVAC system’s efficiency has been reduced
  • You have frequent allergy attacks
  • You notice mold or mildew growing inside your home

Although the exact schedule will vary with different manufacturers, the standard HVAC air filter should be replaced every two to three months. You might also need to change your filter more often if you like to use your HVAC system throughout the day.

Are you looking for a furnace repair near you in Sonoma County to repair your HVAC system? We can help you maintain your HVAC unit and keep it in good shape for optimal performance. To schedule an inspection, call 707-452-3464.

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Our philosophy is simple, we always want to maintain equipment to give it the longest life possible. Next, we want to focus on repairing when something goes wrong. Then only as the last choice, we replace equipment when needed. That’s the John Owens Way.

San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464



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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464