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Filters come in different sizes to fit into your furnace. What you may not realize is that furnace filters also have a depth. That depth matters both for the performance and fit of the filter in your furnace. Here’s what you need to know about comparing furnace filter thickness and which you should choose.

Why Does Furnace Filter Thickness Matter?

A thicker furnace filter has more surface area, and usually substantially more. While an average filter is one inch thick, you can choose one that is up to four inches thick. This extra depth gives the filter more room for airflow. That means that as the filter collects dirt and other debris from your air, it won’t restrict the airflow in your furnace as much. This prevents damage to the furnace and gives the filter itself a longer lifespan. Plus, with that extra depth, the filter can pick up more debris, giving you better air quality.

Do Thicker Furnace Filters Last Longer?

Thicker filters do have a longer lifespan, but exactly how much longer does depend on the air quality of your home and your personal tolerance to poor air quality. Those who have pets will still need to change thicker furnace filters more often than other people. And those with conditions that make them sensitive to air quality, like allergies or asthma, will still need to change a thicker furnace filter regularly.

4-Inch or 1-Inch Furnace Filters

What can you expect if you choose a 4-inch filter over a 1-inch filter? There are some benefits and some disadvantages:

  • Better air quality
  • Longer life
  • Higher cost

You may also need to adjust your duct system to fit a four-inch filter into the gap where your smaller filter once was. Your HVAC professionals can help you adjust the system, it’s a relatively quick job. And then you’ll be able to get the benefits of a thicker furnace filter.

Need help finding out which filter you need for your furnace this winter? Give our experts a call today to learn more.

measuring tool

Can I Use a Thinner Furnace Filter?

What if you have room next to your furnace for a four-inch filter, but you can’t find one or you don’t want to use one? You can still use a thinner furnace filter, but you need to make sure that it stays in place. This may mean moving your air duct system over so that the filter is properly braced.

If you’ll only be using this smaller filter for a very short period of time, you can add a bit of tape to the side to hold it there. However, with the heat generated in this area, the tape may not last very long and the filter will probably let air by.

It’s best to use the filter size that your space can accommodate so that you and your furnace get proper protection. Reach out to Link Climate Care today for help.

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