Lately, Have You Checked the HVAC Filter?

Everyone agrees that we should change the filter in our home heating ventilation air conditioning (HVAC) systems. Actually doing that may be something else altogether. It’s all about the where, when and how of doing it that leads us to procrastination and selective amnesia.

It’s not difficult. The problem is in making it a priority. It’s not that big of a deal, right? If the thing still turns on and cools and/or heats the place, who cares?



Consider these three unintended consequences, which should help push this simple home maintenance task up to a respectable place in your list of things that are important.

High energy bills

When the heat, ventilation or air-conditioning is running, 100% of the air in your home passes through a filter, typically twice every hour. When the filter is clean, the air passes through easily. When the filter gets clogged up with all the stuff it’s filtering out, the system has to work much harder to keep air moving.

The dirtier the filter, the less efficient the system can be—and more likely to develop problems. According to the Department of Energy, regular filter changes can reduce your energy bill by 5% to 10%. Conversely, a super dirty filter will send that bill through the roof!

Family health

A quality filter captures the harmful bacteria typically found in sneezes, coughs, viruses, and molds, as well as pollutants like dust and car fumes. If you have allergies or asthma, indoor air pollution can trigger your symptoms.

Most people don’t realize that indoor air pollution levels are actually much higher than those outdoors—two to five times higher, according to medical professionals. When particles become airborne, you can breathe them in and experience an allergic reaction. The heating, ventilation and air conditioning (HVAC) system in your home can harbor and then spread mold and other allergens.

Grimy carpet stains

It’s called filtration soiling and shows up as dark, shadowy, dirty lines on the carpet along baseboards, under doors, beneath draperies and along the edges and in the crevices of carpeted stairs.


Filtration soil is as ugly as it is gross and comes from airborne pollutants passing through the carpet as the air is drawn through the crack between the carpet and the baseboard, around the drapes or under a closed door.

MORE: What are Those Grimy Black Lines Around the Edges of My Carpet?

Filtration soil is an accumulation of soot from dirty ducts, smoke from candles and the fireplace; tobacco, kitchen grease from the oven and cooktop; smog, auto emissions, and pollutants from outdoors.

The way it’s supposed to work is that all of that stuff in the air gets trapped in the system’s air filter. But once the filter is full, the system will send the air pollutants back into the house through the ducts where all of that icky mess gets lodged into corners and crevices.


Check your filter every month, especially during heavy use months (winter and summer). Keep in mind that some systems have multiple filters. Take some time to research your system to discover exactly what and how many filters you have.

If the filter(s) looks dirty after a month (no longer white) change it. Homes with pets, multiple occupants, undergoing some kind of construction or if yours is located in an area with general air pollution, expect to need more frequent changes.

At a minimum, change the filters every three months. A dirty filter will slow down air flow and make the system work harder to keep you warm or cool, wasting energy. A clean filter will prevent dust and dirt from building up in the system leading to expensive maintenance and/or early system failure.



1. Schedule yourself

Mark your calendar. Set an alarm. Do something that will trigger your memory to check your filter(s) so you can get to the store to buy a new one. Or buy a bunch so you have them on hand. Don’t assume you’ll just remember. You probably won’t until one day, years from now you notice your utility bill has shot through the stratosphere, you have this weird cough or you see odd, dark shadows forming along the edges of your carpet. Or your system dies a tragic, premature death. Don’t let that happen. As long as you change it often, go for the cheapest filter that fits your system that you can find.

2. Do it yourself

Want to save money and stop wasting time trying to figure out which filter you need? Make your next filter a permanent electrostatic filter (also known as a washable one). The WEB Eco Adjustable and Washable Air Filter Plus (less than $30) available in local home improvement centers and online here, can be cut to fit most filter cabinets from 14x20x1 up to 20x25x1. It’s quite simple to do. Washable filters may be reused for 5 to 10 years!

Electrostatic filters should be rinsed once a month and prior to re-installation, they should be allowed to dry. Keep in mind that electrostatic filters are most effective when new and clean, so they should be washed frequently even if they don’t appear to need it.

3. Automate

I had a filthy filter wake-up call a few years ago. The scariest thing ever was to open that door on the HVAC system, dutifully labeled “Filter.” I cannot adequately describe it but I can tell you that it was nearly black and covered in what looked like fur (see photo immediately above). So gross. I’m surprised the entire system didn’t just blow up out of sheer rebellion for lack of attention.

That prompted me to get online to do some research. And that’s how I found FilterEasy, a company that delivers the exact filter we need, just when we need to change it—at a cost that is cheaper than the very same filter at the home improvement center near our home. It’s a great service.

It’s really easy to set up a FilterEasy account online, identify the exact filter you need (they’re listed by size—including custom sizes if the filter you need is not standard) and the frequency of delivery. This takes all of about five minutes. Now you can forget because you’ve put FilterEasy in charge of remembering.

The folks at FilterEasy are offering Everyday Cheapskate readers their first set of filters free (you’ll just pay to ship) when you use this LINK. Of course, you can cancel or make changes to your subscription at any time.

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5 replies
  1. Joni Kelly Lmt
    Joni Kelly Lmt says:

    When I had a business office our A/C man told us with all the open/closing of doors and lack of trees to filter what came in we should change the filter every month. When I finally moved into a house with Central A/C I figured my cats would count for the same challenge. Since then I have marked my calendar for every 3 weeks and change my filters, even if they are only lightly soiled. I work from home and have clients with cat allergies, yet large majority don’t realize I have six cats unless I tell them. Keeping the filter (and, of course, the litter boxes) cleaned so frequently leaves my house smelling great, all the time. Naturally, if there is a kitty mishap Nok-Out takes care of that! Thanks for all your great advice!
    Joni <><

    • Mary Hunt
      Mary Hunt says:

      Thanks for your great feedback, Joni! Makes so much sense when you think of all the stuff in the air. I have a friend with asthma—and it’s getting worse with more frequent episodes. I asked her when did they last change their HVAC filters. Both she and her husband stared at me like I had 3 heads. Uh … whoops! With clean filters now, i’m anxious to hear back from them if this makes any difference. I’m pretty sure, but will be encouraging to hear their results.

  2. Susan4cats
    Susan4cats says:

    My problem is that the filter is behind a trap door in the ceiling in the hallway. It require climbing up on a ladder to reach (or being 7 feet tall). I am handicapped & can’t climb a ladder (I’m also 5’2″ tall). I have to beg to get someone to change my filter.

  3. Debbie
    Debbie says:

    I started using FilterEasy from your recommendation and they are great. I was having a hard time finding the filter for my HVAC, sent them an email and they promptly helped me pick the correct filter and size for my system. Love the automatic subscription service too! When the filter box is at my door, it’s time to change it. Another big plus for me is I am now getting a higher quality of filtering microparticles for $20 less with their filters. All around, it has been a super easy and win win process doing business with them.


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