Buying A Furnace Filter: Tips & Advice

Changing your furnace filter every 90 days helps ensure your furnace runs most efficiently—and it helps with indoor air quality.

But which furnace filter is best for your home? What’s the difference between less expensive and more pricey brands?

Here’s a quick rundown on furnace buying tips and advice:

• Furnace filters have a MERV rating which measures how well it removes particulates from the air. (MERV stands for Minimum Efficiency Reporting Value).

• The higher the MERV rating, the more efficient the filter is at removing smaller particles that contribute to bad air quality (like pollen and pet dander). MERV values range between 1-20.

• After interviewing several HVAC experts, we believe a MERV value between 7 and 13 is best for most residences. 

• The lower the MERV rating, the lower the price (in most cases). A filter with a MERV rating of 1-6 may only remove the largest particles in the air—for example, pet hair (but not dander).

• MERV ratings in the middle (7 to 13) remove fine particles like smoke and bacteria. What about higher rated MERV filters? Those are for medical care facilities or commercial installations where you need to remove even finer particles.

• While 90 days is the general rule, you may want to replace your filter more often in special circumstances. Have a pet that is shedding its fur? Or a wildfire nearby that sent smoke in your backyard? In that case, changing out the filter more often makes sense.

After pouring over third-party research and trying out several brands ourselves, here are our top picks for furnace filters:

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