Your Furnace Filter: So Easy To Change, So Easy To Overlook

As the mid-Ohio area gears up for winter, it’s time to think about your furnace filter. Air filters save money by prolonging the life of heating and air conditioning equipment. Filters also reduce the amount of dust, pollen, mold spores and other allergens circulating inside the home. But they can do their job only if they’re clean. 


The air filter is often located inside the furnace’s blower compartment. Or it can be found in a central air return, hidden behind a grille in the wall of a centrally located room. If your filter is at the furnace, shut off power to the furnace first. The filter may be behind the door to the blower compartment. Or it may simply tuck into a slot adjacent to that compartment. 

With a central air return, there’s no need to shut off the power first. Just open the grille door, often secured with flip-out levers. 

When and how to inspect the filter 

The U.S. Department of Energy recommends checking your furnace filter every month. This is particularly important during peak HVAC usage -- in winter and summer (summer because your furnace blower is often utilized as your A/C's air handler). At minimum, you should change your furnace filter every three months. 

Hold the filter up to a light. If you can easily see light through the filter, it may not need changing. When in doubt, change it. 

When installing a replacement filter, make sure the airflow arrow, located on the filter’s edge, points toward the blower motor. 

Types of air filters 

The least expensive filters are made of reusable, washable glass fibers. They protect the blower motor from dirt, but have little positive impact on air quality. Ironically, as they become clogged, they do a better job of filtering the air. But the price you pay is reduced air flow, which forces your equipment to work harder.

There is a wide range of disposable pleated filters, designed to catch particles of varying sizes – down to as small as 0.3 microns. Some filters are electrostatically charged, to catch more allergens. 

Still have questions? 

Serving the mid-Ohio area since 1965, Joe Behr Plumbing and Heating is always happy to help. We’ll gladly answer questions about your furnace filter or any other home comfort concerns.

Our goal is to help educate our customers in the Mid-Ohio area about energy and home comfort issues (specific to HVAC systems).  For more information about your furnace filter and other HVAC topics, visit our website.

Image courtesy of Shutterstock

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