Reasons Why Your Air Filter Always Looks Dirty

Reasons Why Your Air Filter Always Looks DirtyThe sight of a dirty air filter in your HVAC system should be no surprise: the average system pushes about 1,000 cubic feet of air through the filter every minute while it’s running. That’s why regular air filter changes—every month during the summer and every month or two in winter—are critical. However, a filter shouldn’t need replacement sooner than that. If you check between changes and a dirty air filter looks back at you, it could be a sign of issues elsewhere.

Fan All the Time

Your HVAC thermostat offers two fan settings: “Auto” and “On.” In the “auto” mode, the fan runs only when the A/C or furnace cycles on. When the unit cycles off, air circulation through the filter stops. In the “on” setting, however, the fan runs non-stop, pushing air through the filter continuously and rapidly accumulating dirt, dust and other particulates. Some people prefer continuous air circulation for air quality benefits. If you’re one of them, you’ll have to make a note to check/replace the filter more frequently.

Maybe it’s the Filter

For most residential applications, air filters with MERV (Minimum Efficiency Reporting Value) ratings between 8 and 12 provide the best balance between filtration efficiency and system airflow. If a higher-efficiency filter above MERV 12 is installed without modifications to the ductwork and blower, however, the thicker filter media may accumulate excessive dirt and dust faster and clog earlier, restricting system airflow.

Fido and Fluffy

All dogs and cats shed hair—a little or a lot. Pet hair clings stubbornly to surfaces like carpets or upholstery, yet also floats in the air and is sucked into HVAC ducts. From there, it’s captured by the system air filter. Matted pet hair covering the filter causes dust and dirt to accumulate faster than normal, clogging the filter sooner. Pet shedding can be reduced somewhat by daily brushing outdoors and “dogged” efforts to vacuum up shed fur before it becomes airborne.

If a dirty air filter is becoming an overly-familiar sight, ask the pros at Paitson Bros. to check it out. We’ve been your local HVAC problem-solvers 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.

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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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