Four Common Air Filter Mistakes

[Disclaimer: This post is brought to you by Trane. Thanks for supporting the brands that support The DIY Playbook.]

Remember when we chatted all about the big mistake I made during our renovation…not paying attention to our HVAC system? Yikes. Things were dirty up in there. Luckily, I was able to get everything spruced up, post-renovation, and things are now much cleaner and healthier around here! You might not have a big renovation or DIY project coming up that will create lots of dust, but there is something that you should be doing regularly to keep your air fresh…changing your air filter!Remembering to change our air filter

In the past, I haven’t always been great about remembering to change our air filter. I would sometimes go for months and months without changing it and then it would be filthy by the time I eventually got around to it. With this house, I’m aiming to be better and stay on top of our home maintenance. My plan is to set up a system from the start so I can stick with those good habits through our time here.

Four Air Filter Mistakes You Might Be Making

4 common air filter mistakes

As I researched the best air filters to get for our two units, I learned a lot about air filters. I seriously had no idea how important they really are and how important it is to buy the correct one for your unit. Here are some common mistakes people make when it comes to their air filters (I’ve pretty much made all of these…).

1. Never Changing Your Air Filter

An air filter’s job is to clean the air that circulates through your heating and cooling system.  When air filters get dirty, they restrict air flow to your HVAC system which makes it work harder and longer (leading to higher utility bills!). They also have a max holding capacity so once yours is full, the bacteria, allergens, and dust can come through into your air supply. Yeesh. I had a terrible sinus infection last year and the last thing I want is for that bad boy to come back this winter.Before and after air filter

If you don’t ever change your air filter, then you may run into some problems. The above photo shows the air filter I took out of our unit after our renovation (so filthy!) and the one on the right is a new clean one.

If you hold them up to the light, you’ll see that the dirty air filter is sooooo filthy! Look at all of that stuff that was in there! I’m horrified.

Trane air filter packI ended up buying a bunch of these air filters from Trane. These Comfort Performance Air Filters only have to be changed every ninety days and they work with every single HVAC system, regardless of make or model.

Set a reminder on your phone to change your air filterMy tip? Set a reminder on your calendar to change your air filter every three months. When something is set on my calendar, I know it will get done. So, go ahead and add your reminders for the next year and hopefully, you won’t forget. Find a system that works for you so you remember to change that filter regularly.

2. Putting Your Air Filter in the Wrong WayThe air flow of my air filter

When our inspector looked at our house before we bought it, he found the air filters on both of our units were put in backward.  Palm to forehead. Luckily, we paid attention to our inspector and learned the correct way to install new air filters. If we would have just followed the former homeowners, we would have been putting them in wrong for years to come!Pay attention to the air flow on the air filter

Look for the arrow on the side of the air filter. The arrow must always face toward the furnace and away from the return duct that carries the air. My units actually have “air flow (with an arrow)” written directly on them. If you put it in backward, then it won’t be working to filter out the crud that goes into your air.

3. Not Paying Attention to Size

16x20x1 air filter

I’ve definitely made this mistake. In our condo, we had a very strange size for our air filter and we would have to jam it in there. It was not good. It’s important to get the exact size so it has a tight fit in your unit. This prevents air from getting around the filter. If it’s too small, then air can get around the edges, bypassing the filter altogether!Trane air filter

The new Trane Comfort Performace Air Filters come in a variety of sizes, so make sure to buy the correct ones for your particular unit. My best advice is to buy a large pack of them so you always have them on hand when it’s time to change them and you don’t have to scramble to buy new ones.

4. Ignoring the MERV RatingPay attention to the MERV rating

MERV, what?! Yeah, I was the same way. MERV stands for Minimum Efficiency Reporting Value. These range from 1-20 (1 least effective and 20 most effective) and it measures the ability to filter particles from the air. For example, hospitals use filters with a MERV rating of 16 or higher! Not all filters even have a MERV rating. Personally, I’ve always purchased filters with a MERV rating. These filters from Trane have a MERV rating of 9 which can capture pet dander, pollen, mold spores, and dust!

If you have asthma, allergies, or pets you will probably want to opt for filters with a higher MERV rating.

Let’s All Breathe a Little Easier

Changing out our air filter

When I was researching for the blog post, I immediately wanted to go change our air filter, haha. So I’m guessing you’re feeling the same way right about now! I’m usually chatting about the way a home looks, but the air in your home is incredibly important.

Here’s your to-do list…

  • Make note of your correct air filter size
  • Buy a large pack of filters
  • Set a reminder on your calendar to change the filter every three months
  • Change your filter and put it in the right way

Make sure to change your air filter regularly!

Home maintenance isn’t always sexy or glamorous, but it’s necessary (and sooooo doable!). I hope this post gave you the kick in the butt to make a simple switch in your home.


The Year of Casey

Hey there!

I’m Casey Finn, the voice behind The DIY Playbook. I’m a Chicago gal teaching you how to design, DIY, and maintain your home…by yourself! Learn more about me right here.

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