Air Filter Keeps Bending – Why And What To Do?

An air filter functions by cleaning the air that is being circulated through the system. This not only helps to enhance the air quality inside of your home, but it also helps to prevent harm to the HVAC system. Over time you might notice your air filter bending when it's turned on. If you would like to know why and what to do when this happens, we asked HVAC experts for help. 

If your air filter keeps bending, it results from the pressure exerted by the blower fan. This normally occurs in air filters that have been constantly used for years with little or no maintenance or cleaning. The best way to fix this is by repairing or changing the filter entirely. 

This article explains, step-by-step, why your air filter keeps bending and what to do when this occurs. 

A person removing an old dirty air filter from a ceiling intake vent, Air Filter Keeps Bending - Why And What To Do?

Why Does Your Air Filter Keep Bending?

It is possible for a filter to bend under pressure exerted by the blower fan on it if the filter becomes significantly clogged. This could result in the filter becoming lodged within the blower motor itself. This might cause major damage to the motor, and it will need to be repaired as soon as possible by professionals.

Also, when people accidentally purchase the wrong size filter, they are sometimes inclined to try to make it fit by bending or folding it. However, you should avoid doing that since it permits air to flow around the filter, which opens the door for dirt and other particles to enter your HVAC system. 

How To Fix Bending Air Filter

Fixing a bent air filter is vital to ensure that the filter is installed correctly. To begin, power off the ventilation system and then look for the filter. Take note of the filter's position in its slot before attempting to remove it from the slot.

Removing air filter

Use a permanent marker to write an arrow on the frame that holds the filter so that you can keep track of the correct air-flow direction and match it to the arrows found on most filters. This will ensure that you do not lose track of the correct air-flow direction.

The vast majority of HVAC filters do not have a design that allows them to be used on either side; instead, they have to be placed in a particular manner for them to be functional.

The drawn arrow helps prevent the common human error of not paying attention when removing the filter. The good news is that after you have done it once or twice, changing the filters in your air conditioner (or furnace) will become an easier process. 

Can You Use a Bent Air Filter?

In terms of appearance, a slightly bent air filter isn't too noticeable and can still be used. If it has become compressed, you may easily straighten it back out.

It is not necessary to replace the filter; however, you should attempt to restore as much of the original surface area as possible by straightening out the bends in the tubing as much as you can.

Check out the BNX MERV 13 Filter Pack on Amazon.

How Often Should You Change Air Filter?


Every 30–60 days, a pleated air filter that is 1-inch in size needs to be replaced. Altering a pleated air filter that is 2 inches thick every three months is recommended. Every 120 days, you should replace the pleated air filter that is 3 inches thick.

Changing a pleated air filter that is 4" in size every six months is recommended. Changing your home's air filter once every 90 days, or three months, is recommended by the majority of HVAC firms and manufacturers of air filters.

A number of factors can impact this, including:

  • the age of your system and equipment,
  • the presence or absence of pets in the home,
  • and dusty or dry conditions.

What If My Air Filter Is Too Big?

If the filter is too large, it won't be able to fit into the slot for the filter, which will prevent you from being able to replace the cover. This can result in dirty air being drawn into the interior of your heating system (and home).

When you use an air filter that is not the correct size for your HVAC system, the most significant risk is that it will not properly stop dust from accumulating on the motors and blowers of the system.

This causes your furnace to become dirty, which may have an effect on its performance and may also cause damage to the system's interior components, which can result in expensive repairs or replacements.

It is important that your air filter completely covers the opening of the duct. Take into account a small amount of overlap if there is space available while measuring the height and width of the duct entrance. This will be the precise dimension that you need to specify when you place your purchase for the replacement air filter.

Why You Should Not Use Choose The Wrong Filter

Here are issues that can come up if you use the wrong air filter

Inadequate Fit 

Before you go out and buy a replacement air filter, make sure you measure the size of the one you currently have. If you buy a filter that is too large for the slot, it won't be able to be inserted into the slot correctly.

If the filter is too small, it won't be able to cover the full space, and it might not prevent dust and dirt from getting through. If you are unsure of the size of the filter that you require, check the specs provided by the manufacturer or consult with an HVAC specialist for assistance in selecting the appropriate product.

Damage to Your Air Conditioner

There are a wide variety of MERV ratings available for air filters. If a filter has a higher MERV rating, it means that it has a finer mesh and is able to remove smaller particles from the air than other filters.

However, you should not use a filter that has a rating that is higher than what your device was built for in order to avoid damaging it.

If the mesh is too fine, the energy required to move air through it correctly will be too great for your HVAC system to handle. This could result in significant damage to either your furnace or air conditioner.

Can I Use My HVAC Without a Filter?

It is possible for an HVAC system to function without a filter, although doing so is not recommended. In the absence of a filter, the system will pull in unhygienic air and then return that same unclean air into your indoor environment, which will contribute to health problems.

There is a window of time during which you can safely operate your air conditioner without a filter without causing any damage.

In light of this, allowing your air conditioner to run without a filter for more than six to eight hours can lead to substantial damage to your air conditioner as well as a considerable decline in the quality of the air in your home.

If you don't have a filter, the condensation drain on your AC unit won't be able to remove the moisture from the air. Condensation will begin to form on the freon tube as a direct consequence of this. When this happens, the condensation will begin to flow down the pan, which will result in water damage to the entire system.

What Happens If Air Filter is Backwards?

Texture of air filter

Installing the filter backwards will make it more difficult for air to pass through the filter, which will make the air handler do more work to complement the low airflow. This could cause your utility bills to go up, in addition to possibly causing damage to your heating and cooling system.

In addition, if you install your filter in the incorrect orientation, the end of the device that is ordinarily collective will not be facing the air supply. This means your filter will contribute to debris retention in the air. Consequently, the filter becomes clogged, and the air that reaches your lungs is not cleansed effectively.

How Tight Should An Air Filter Fit?

The filters do not have to fit with an "airtight" seal; nonetheless, you should be able to simply install and uninstall your filter without any trouble. Additionally, the filter should not be so small that it slides freely within your unit.

If you have to bend, force, or jam your air filter into position, then you have a filter that is too large for your system. If, on the other hand, your filter does not fit within the width of one to two fingers of any of the four corners of the slot or frame that is part of your air system handler, then your filter is too small.

Can You Wash An Air Filter?

Dirty dust filters of air conditioner ready for cleaning

Filters that can be reused can be cleaned and reused multiple times. However, the disposable filters that you use in your heating, ventilation, and air conditioning system were not designed to be able to shed water once they become wet.

Mold growth may be encouraged over time by the moisture that is retained by the filter, and your HVAC system may be responsible for spreading the mold spores throughout the rest of your home.


Changing out your air filter consistently is one of the most important things you can do to maintain the efficiency of your heating, ventilation, and air conditioning system. Always give the filter for your HVAC system the care and attention it needs. 

If you would like to read more about air filters, check out these engaging articles: 

6 Types of Air Filters For Your Home

What Way Does Air Filter Go In The Ceiling

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