6 Furnace Air Filter Tips

A question asked quite often by my customers is, “How often should I change my furnace filter?” Another popular question is, “Why do you carry so many Band-Aids?” but that’s another story (sheet metal joke). Anyway, air filtration is very important to homeowners for a multitude of reasons. We usually think about our furnace’s air filter when we’re dusting the coffee table or when the kids are suffering from an asthma attack in the middle of the night. “The dog is sneezing again. Must be time to change the furnace filter.”

So we get in the car and drive to the big box mega home improvement depot store only to find an aisle a mile long filled with thousands, maybe millions of different air filters! The shelves are full of furnace filters of different sizes, different purposes, and wildly different prices. There’s not a soul in sight wearing an apron or a vest; no one to help with this allergy changing decision. The fifty-cent filter says it lasts 30 days, but it looks like a herd of cows could walk right through it unimpeded. The twenty dollar “air cleaner” claims to last 90 days, but do I really want to spend that much money on something made by the same people who make invisible tape? Well, tape is sticky and I want the dirt to stick to the air filter so . . . the 20 dollar filter it is!”

Sound familiar? Has your furnace maintenance experience been this frustrating. It doesn’t have to be!


Furnace Filter Tips


  • Filter replacement frequency varies by filter type and by the size and “dustiness” of the home. The furnace in a large home moves more air and will clog the filter faster. If you have pets you’ll probably need to change your filter twice as often. Not only are pet dander and pet hair leading allergens, they also clog filters very fast! Start with every two months for a pleated 1” filter and double the frequency if you have a large home or if you have pets. I know the $20 filters claim to last 90 days, but, in my experience, these filters are so restrictive that they should be changed once a month. Your furnace and air conditioner will thank you. If you’re ready to get serious about clean air, we can install an Aprilaire whole-house air cleaner in place of your furnace filter. These filters clean the air better that any of the 1” filters at the hardware store and they only need changed once a year.
  • Buy your filters by the case (usually 6 to 12) and store them near the furnace. This will lessen the tendency to procrastinate your air filter change. Buying by the case can also reduce the cost of each filter change.
  • Get in a routine of regular filter changes just like you do with your car’s engine oil. Many modern thermostats have a timed filter reminder built-in, but it needs to be setup. It’s free and could save you hundreds in possible repairs.
  • Never run your system with an incorrectly sized filter. An ill-fitting furnace filter will allow dust and other contaminates to sneak around the filter and into your home. We call this “filter bypass” and it is the main cause of clogged air conditioner coils. Clogged a/c coils greatly reduce efficiency and compressor life, and will cause expensive problems down the road.
  • Always turn off your furnace at the breaker panel or disconnect (not just the thermostat) before replacing your filter. Some furnaces have electrical wiring close to the filter location which could shock you if the power is not disconnected first. furnace air filters
  • Lastly, don’t guess. If you are uncertain about where your furnace filter goes, what direction to install it, or what size or type to get, ask a professional. Give us a call or stop by, we’re always glad to help. We have a wide variety of filters in stock at our Springboro location, and at great prices too. Come in and pick up a case. Better yet, sign up for our service agreement and leave this dirty job to the pros.


Upgrade Your Indoor Air Quality


If you are wanting to reduce allergies and improve asthma and sinus symptoms, then a standard one inch thick filter that you buy at the hardware store is probably not the answer. There are many choices when it comes to high-efficiency, whole-house air cleaners and other Indoor Air Quality devices which can greatly improve your family’s health. Our technicians can recommend the best solution based on the individual issues in your home and your family’s allergies. Holistic indoor air quality will be a future blog post. Until next time!

David Watkins

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