Reasons Why An AC Filter Keeps Bending – How To Fix It


More than 88% of households across the United States use AC or HVAC systems to improve indoor air quality, cool, and ventilate their homes with clean, cool air. However, during use, air conditioner filters can begin to bend and require fixing for the system to continue to operate.

An air conditioner (AC) Filter keeps bending because it is a wrong-sized or worn-out filter. An incorrectly installed filter, or incorrect type of the filter can also cause bending. The most common reason for an AC filter bending is an incorrectly installed filter.

This article will take you through all the possible reasons why an AC filter may keep bending, provide diagnostic features so you can determine your specific problem, and, most importantly, provide step-by-step instructions on how to solve it.

4 Reasons an AC filter may keep bending

Here are the four reasons why an AC filter begins to bend, and keeps bending.

However, if your AC filter is also wet, Plentiful Air has a complete troubleshooting guide on how to fix and prevent the problem available here.

1. Wrong-Sized Filter

One really common reason for an air conditioner filter to keep bending is a wrongly sized filter. Especially if the filter is too large.

Every air conditioner uses a filter, but with so many different sizes of air conditioners, there is a huge variety of filters to fit each type. If a larger filter size is installed in a small fitting, the system can experience a range of problems, including bent filters. The filter will become bent because of the air flow moving in and out of it as the AC system works, ultimately pushing the filter out of place.

A poorly sized AC filter can also be too small, but these rarely become bent. They simply won’t cover the entire space, and dust and dirt will pass through and easily damage the AC unit.

Every air conditioner comes with a manufacturer-recommended air filter, so make sure you know and are confident of the size to avoid buying the wrong one. If you happen to receive your product and discover that it is the incorrect size. Instead of trying to force the incorrectly sized filter into place, be sure to return it and receive the correct size (or a refund).

This is one of those things that is simply not interchangeable in your AC.

Apart from the filter bending, the inefficiency of your entire system is reduced when the wrong size is used. This can quickly mount up, becoming a more visible issue when you get your next electricity bill.

Diagnostic properties of a wrong-sized AC filter.

  • Noticing that the filter is too big during installation.
  • Noticing that the AC filter keeps bending and moving out of place.
  • Dust and debris particles are going through and entering the air conditioner.
  • Poor indoor air quality.
  • Increased utility bills.

Solutions

  • Turn off the entire AC or HVAC system.
  • Access the filter compartment.
  • Open it and check if the installed filter was of the correct size.
  • If not, remove it from the filter compartment, ready to replace it with the right one.
  • Remove the new filter from its packaging and put it in place.
  • Always consult the user manual handbook or a professional on the right filter for your air conditioner before filter replacement (an easy way to check is often to use the chat or contact us section on the brands website – this can give you a quick answer without you having to wait on the phone)

2. Old Filter

An old filter can sometimes cause an AC filter to keep bending. Over time, all air conditioners filters suffer from wear and tear and ultimately require a replacement. Both washable and disposable filter types require regular replacement (instructions on how frequently you need to replace your specific filter can be found in your user manual).

The replacement time may vary depending on the quality of the air conditioner filter you use. Or whether it is a genuine or generic branded filter.

A prime example of an old filter becoming a problem is a washable filter that has not been changed in a very long time (even if it is regularly cleaned). These filters become worn out after successive washes, making it weak and susceptible to bending after being installed, especially when it becomes totally clogged with particles such as dirt, mold, dust, hair, pet dander or fur during operation.

Disposable filters, on the other hand, also have the limited time before they are supposed to be replaced, but this may change, especially if your home is dusty, has furry pets, or there is an ongoing construction going on in the neighborhood making the filters to be clogged quickly.

Diagnostic features of a worn-out AC filter.

  • If you have not replaced the filter for long periods of time.
  • Poor indoor air quality.
  • It keeps bending.
  • High electricity bills.
  • AC becoming too hot and unable to cool.
  • Frequent allergy attacks due to poor indoor air.

Solutions

  • Switch off the entire AC or HVAC system.
  • Locate the filter compartment and remove the filter.
  • Access the state of the filter.
  • Is it totally worn out and requires replacement?. A worn-out filter is totally clogged, bent, and weak. If that is the case, replace it with a new one.

3. Incorrectly Installed Filter

An incorrectly installed filter is the most common cause of an AC filter to bend and keep bending. Incorrectly installed AC filters are those installed in the wrong way, which means that they are facing the wrong direction or have not been attached as well as they should, and do not create a good seal. 

If a filter is not well attached, it is prone to bending when the unit is turned on, and the air is pushed in and out. Either way, if only one side is attached well and the other is not, the filter can bend.

Some manufacturers include arrows to show the direction in which the filter is supposed to face, making it easy to avoid this problem.

Diagnostic features for an incorrectly installed AC filter

  • You are unsure of what direction the AC filter is supposed to face.
  • You notice increased electricity bills and a change in indoor air quality since replacing the filter.

Solutions

  • Turn off the entire AC or HVAC system.
  • Locate the filter compartment.
  • Confirm if the filter was installed incorrectly initially.
  • If it was, remove it and install it correctly.
  • Consulting your user manual on how to replace filters not to repeat the same mistake again.
  • Hire an AC or HVAC professional to install filters for you are unsure at all.

Plentiful Air has more information to help you stop your AC filter from whistling available here.

4. Filter Type

Low quality air filters could also be why your AC filter keeps bending. There are different kinds of AC filters available commercially, and they vary depending on size, quality, or material. Some are weaker than others, while some are cheaper than others.

Cheap filters are usually of very low quality and material, so they can become significantly bent with time if the replacement period is exceeded.

Some AC filters that are currently available include fiberglass and pleated filters, although there are others. Except for the cardboard frame, most fiberglass filters have little to no construction material woven into the filter cloth, similar to pleated filters.

However, these filter constructions will fail over time, causing the cardboard filter frame to bend into the return box.

Pleated filters feature support weaved into the filter material, usually metal or plastic cording, to help the filter withstand the blower fan’s pressure. However, they can fail, causing the filter frame to bend into the return box over time.

Solutions

  • Use only filters recommended in the user manual.
  • Use a high airflow filter.

How do I keep my AC filter in place?

To keep an AC filter in place, ensure you purchase the correct filter size, read the user manual recommendation instructions and install the filter as directed by it. In particular, follow the direction in which the arrows are to face (located on the filter and displayed in the user manual) and ensuring that its cover is fastened into place.

Why does my AC filter keep collapsing?

An AC filter can keep collapsing because the volume of air being moved is higher than the air filters can accommodate. Low quality air filters, incorrectly sized filters, or the filter housing providing insufficient support are the leading causes of an air filter being unable to cope with a given volume of airflow.

Russell Singleton

Russell holds a Bachelor of Science (Environmental and Marine Geoscience) with Class I Honors. He is currently completing his doctorate in science and is passionate about all earth processes, especially isotope geochemistry and paleohydrology.

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