What Do Furnace Filter Arrows Indicate?

What Do Furnace Filter Arrows Indicate?When it comes to changing a furnace filter, there’s a right way and a wrong way. Arrows printed along the edge of the filter are there to make sure you get it right.

Why Changing The Filter’s Important

In a typical home, over 1,000 cubic feet of air pass through the filter every minute while the system is heating or cooling the house. The filter plays a critical role in both safeguarding indoor air quality by removing particulates from household air as well as protecting furnace components from accumulation of dust and dirt that can affect performance and reduce service life. When a filter gets dirty and clogged, airflow throughout the entire system is reduced and heating/cooling performance and efficiency suffer.

Why The Arrow Matters

Air drawn out of rooms flows through the return duct back to the furnace, where it’s re-heated then pushed through supply ductwork throughout the house. To ensure proper filtration, the furnace filter needs to be oriented so the filter media faces the right direction as indicated by the arrows.

If you’ve never changed the filter before—or have, but maybe aren’t certain you did it right—it’s a good idea to have a qualified HVAC service tech demonstrate how at first. Here’s how the basic procedure goes:

  • Find the filter slot in the system return duct.
  • Slide the old filter out of the slot and discard.
  • Use a rag to wipe away any accumulation of dust and lint in and around the filter frame.
  • Orient the filter so the arrows printed on the edge point toward the furnace unit, in the direction of system airflow, not back toward the return duct.
  • Slide the new filter into the frame inside the slot.

Check the filter monthly and change it at least every other month during the heating season. In summer, when the air conditioner’s running many hours per day, monthly changes are recommended.

Qualified service techs at Paitson Bros. can change your furnace filter and show you how to do it yourself next time, if so desired. We’ve been your local source for heating/cooling excellence since 1922.

Our goal is to help educate our customers in Terre Haute, Indiana about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 812-645-6859.

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    Jeff Paitson Jeff Paitson is a third generation business owner who continues to run the business with the same values that have been passed down from previous generations since 1922.

    Jeff’s belief is that the business belongs to Jesus Christ; therefore 10 percent of the company’s profits go toward the Maryland Community Church.

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    Ethan Ethan Rayburn is a lifelong resident of Terre Haute and a 2005 graduate of Purdue University.

    An Eagle Scout, Ethan spent four years as a non-profit executive with the Boy Scouts of America before joining Paitson Bros. as a comfort advisor and later General Manager. In that role, Ethan has brought a renewed enthusiasm for customer care, integrity, value, and service to Paitson Bros. Heating & Air Conditioning.

    Ethan enjoys singing and was a member of the Purdue Varsity Glee Club. He also enjoys playing and coaching soccer, spending time with his family and two young boys, and volunteering his time and resources with his church, Terre Haute First Baptist Church, which he has attended from a very young age.
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