Can a Dirty Air Filter Affect Your AC Cooling?

Dirty Air Filter

Can a dirty air filter cause ac not to cool? The truth is, a dirty air filter often takes the blame when your AC unit is not working the way it should. Most problems come from dirty air filters and lead to your AC breaking down in the most extreme case.

If your air conditioner is not working, licensed technicians can look at your air filter. In most cases, they clean or replace it with a new one if they find it necessary.

Dirty and clogged air filters bring problems to your AC system. They will not only make you spend more money on energy costs, but also they will create irreparable damages to your AC unit. The air filter is kind of a lifesaver for your air conditioner, but it’s also one of the most significant inconveniences.

It’s essential to keep dust and dirt out of the sensitive components of your AC. It’s better to add it to your list of reminders because the air filter will get clogged with dirt often. And if you don’t remember to change it frequently, it can cause a whole range of problems that may appear more severe than they are.

When your air filter is clogged, it blocks new air from getting into your system. This makes your AC unit work harder to draw air from the room and blow out clean air from the vents.

So, yes, a dirty air filter can cause your AC not to cool. Let’s look at how this can happen.

Low Airflow

Dirty air filters lead to poor airflow.

Your air conditioner depends on solid airflow and a fan to blow the newly created cold air from the vents and to the rooms of your home. If a clogged filter compromises this airflow, you can expect to feel a lower flow of cool air coming from your vents.

On the other hand, clean air filters efficiently give out clean, fresh, and cool air. So, can a dirty air filter cause ac to not cool? Answer: Yes it does.


A dirty air filter is regarded as one of the most common reasons why an AC system fails.

Short-cycling is the process of your air conditioner turning on and off too rapidly. In most cases, it may be caused by a dirty air filter. Other causes of short-cycling include having an oversized AC unit or a refrigerant leak.

If changing the air filter does not resolve your short-cycling troubles, you most certainly have a serious AC problem. And if you don’t fix it right away, your AC may fail.

Frozen Evaporator Coils

You won’t suspect a dirty air filter to be the cause of this problem if you’ve never heard of it before.

There are metal boxes full of copper tubes called coils in both your air conditioning system’s outdoor and indoor units. The indoor coil, the evaporator coil, absorbs the warm air inside your home to send it outdoors. However, if the evaporator coil cannot absorb heat, it can cause things to get real cold fast.

In the case of the dirty air filter, excess dirt and dust will cover the evaporator coil and create an insulator. Before long, the ring will get so cold that it becomes a big block of frost and ice. And this will prevent your AC from working well. It will prevent it from cooling your house.

To resolve this issue, turn off the air conditioner and let the ice to melt. Then contact your HVAC professional. A frozen coil, like short-cycling, can be caused by other larger concerns that should be addressed as soon as possible.

It blocks your AC air handler

Can a dirty air filter cause your ac not to cool? Yes, it can. It does so by blocking airflow into your HVAC system’s air handler.

This blocked airflow brings additional strain on the air handler fan motor. And can, over time, burn out the motor and make your system overheat, leading to its failure.

Filter changing is a small price to pay to continue the life of one of the biggest financial investments in your home.

Other problems of a dirty air filter

  • A clogged air filter also causes your fan motor to work harder and use more energy. Changing your air filter is the simplest and most direct approach to reduce your energy bill.
  •     A dirty air filter can also make your ducts get dirty faster. This may lead to costly HVAC cleaning expenses or a need to change your HVAC unit or HVAC components sooner than you suspected. Dirty air filters can infect the heating and cooling coils with dirt. And this makes the system work harder. It also increases the risk of your HVAC system freezing or burning out.

Final thoughts.

After answering the question, “Can a dirty air filter cause ac not to cool?” Here are things to note:

 Your air filters are essential in your heating and cooling system. An HVAC repair ranges from $600, and a complete repair (short of a replacement) can easily reach $7,000. In case of irreparable damage, you will have to get a new AC or HVAC system at around $10,000.

Air filters cost very minimal when compared to the cost of repairing or replacing your entire home’s heating and cooling system, so cleaning them regularly will save you a lot of money. If you want to prevent any of the issues mentioned above, check your filter once a month and replace or clean it before it is clogged.

If your air conditioner has a reusable filter, clean it and let it dry completely before placing it back in. We recommend at least checking your air filter once a month, but advanced filters can last a bit longer. It is wise to call the manufacturer for a recommended replacement schedule.

Also, you mustn’t let your air conditioner run without a filter ever. Without a filter, your unit will allow dust and debris to enter the internal components of your system, leading to potential catastrophic issues down the road.

Regular check-ups are not only necessary to keep your HVAC system running efficiently and adequately but keep your warranty valid as well. For more thoughts about air filters and AC maintenance, you can check up





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