Is it time to change the air filter?

When it comes to home maintenance, few tasks are as overlooked—and as debated—as changing your HVAC air filter (also known as a furnace filter). Yet this simple step plays a crucial role in keeping your air handler clean, your indoor air breathable, and your heating and cooling system running efficiently.

Why HVAC Air Filters Matter

Your HVAC air filter acts like a mask for your air handler, trapping dust, pollen, pet dander, and other airborne particles before they can clog up your system. Just like you wouldn’t wear the same dust mask for months on end, your air filter needs regular replacement to do its job effectively.

How Often Should You Change Your Air Filter?

There’s no one-size-fits-all answer. The frequency depends on several factors:

• Indoor air quality

• Presence of pets

• Allergies or respiratory conditions

• Filter type and MERV rating

Best practice: Change your HVAC filter at least every 90 days. If you have pets or allergies, consider replacing it every 30–60 days.

Understanding Filter Sizes

Filter size isn’t up for debate. It must match the dimensions of your HVAC return vent exactly:

• Too small: The filter can get sucked into the system, allowing unfiltered air—and particles—to pass through.

• Too large: It won’t fit properly, reducing its effectiveness and potentially damaging your system.

Always check your current filter or HVAC manual for the correct size before purchasing replacements.

What Is a MERV Rating?

The MERV (Minimum Efficiency Reporting Value) rating measures how well a filter captures particles:

• MERV 1–4: Basic filtration (pollen, dust mites)

• MERV 5–8: Standard home use (mold spores, pet dander)

• MERV 9–13: Superior filtration (fine dust, smoke, bacteria)

While higher MERV ratings trap more particles, they also restrict airflow. For most homes, a MERV 8 strikes the right balance between filtration and efficiency.

Bonus Tip: Use Air Purifiers

For cleaner air and less strain on your HVAC system, consider adding air purifiers throughout your home. These devices use their own filters to remove particles from the air, improving indoor air quality and extending the life of your HVAC filter.