How Often Should You Change Your Air Filters?

As mentioned above, your HVAC filters should be replaced every 30 to 90 days. The exact timeline can vary based on filter type:

• Fiberglass filters. Fiberglass filters only trap large particles, which means they fill up quickly. This also means they need to be replaced often (about every 30 days).
• Pleated filters. Made from polyester or cotton paper, pleated filters have a large surface area and can trap smaller particles (including pollen, dander, and mold spores). They're more efficient than fiberglass filters and usually last 60 to 90 days.
• HEPA or high-efficiency filters. Known for catching and removing airborne particles, HEPA filters are highly efficient and have a long lifespan. They only need to be replaced every 6 to 12 months.

It's important to note that these are general timelines — other factors, including climate, lifestyle, and system usage, can also impact your filters. Your HVAC manufacturer can provide more specific timelines based on your personal needs.

You may need to replace your air filters more frequently if you meet any of the following conditions:

• Pet ownership. Pets shed hair and dander (or small skin flakes), quickly clogging air filters.
• Allergy or asthma conditions. Pollutants trigger allergy symptoms and asthma. To prevent symptoms, it's important to change your filters frequently.
• Indoor smoking. Tobacco smoke releases particles and tar that clog filters and reduce their effectiveness.
• High home occupancy or frequent guests. The more people in your home, the more dust and skin particles are generated.
• Dusty or high-pollen outdoor environments. Arizona experiences dry seasons and monsoons, which increase dust and pollen levels. As a result, Arizona homeowners need to replace their filters more often than homeowners in more temperate areas.

Here are some key signs that your air filters need changing:

• Increased allergy or respiratory symptoms
• Problems with filter appearance (i.e., looks dark or dusty when held up to light)
• Dust buildup (especially on vents)
• Weak or uneven airflow
• HVAC problems (such as an overworked system or short cycling)
• Sudden increase in energy bills

Dirty air filters do more than lower air quality; they also cause the following problems:

• Reduced airflow. Clogged filters block airflow, leading to uneven cooling or heating.
• Overheating. Dust buildup may overheat the system and force it to shut down.
• Increased strain. When your system is clogged, it will overwork itself to meet your temperature needs. This can shorten lifespan and increase energy use and costs.

We've reviewed how often you should change furnace filters, but what else can you do to ensure clean, efficient airflow? Here are some helpful tips:

• Check filters monthly. Check your filters monthly to ensure they're not clogged (especially during peak seasons, such as dry or monsoon seasons). If you're worried about forgetting, consider using calendar reminders.
• Keep an extra supply. Maintain extra filters so that you can easily swap them when needed.
• Use higher-efficiency filters. High-efficiency filters improve performance and don't need to be changed as often.
• Schedule HVAC maintenance. During a routine maintenance appointment, the technicians will check for quality issues and change the filters. Generally, you should schedule maintenance at least twice a year.