Running an AC without a filter

January 27, 2022
5 min read
Running an AC without a filter

What happens when you run an air conditioner when there is no air filter?

If you are wondering if it is okay to be running your air conditioner without an air filter, the answer is simple. No.

An air filter is an important part of your home’s entire cooling system. Just because it may seem like the least expensive component of your entire system, does not mean it is not important.

Will your AC work if you run it without a filter? Yes. And that is unfortunate, but as we will go over, you are putting your home’s system at risk of breaking down and creating a whole host of other problems.

Tommy Cool Air is the right team of AC repair experts here in Corpus Christi. Our technicians are trained and experienced to work on any type of cooling system and to handle any needed repair. All too often we run across air conditioning problems that were avoidable. Sometimes a repair is needed simply because the homeowner didn’t have a clean air filter installed in their system.


Condensation Drain Problems

outdoor unit, running ac without filter

The condensation drain allows moisture to leave your AC unit. Running AC without a filter, it can fail to function. This can cause condensation to accumulate which will likely lead to a leak and damage your entire system.

Poor Indoor Air Quality

Your air filter filters out dust and debris, and also even very small particles of pollutants. It is quite amazing what all gets filtered out of your system before the cooled air gets pushed through your vents. But without a filter, there is nothing to stop the dust, dirt, and contaminated particles from getting into your home and into the air you breathe.

If you suffer from allergies, asthma, or other respiratory issues, it will not likely take long for you to feel the negative effects of running an air conditioning system without a filter.

Problems in the Ducts

Dirt that does not get filtered out by a filter makes its way into your ductwork. While this leads to the previously mentioned issue of poor air quality, it causes yet another problem. This creates increased moisture in your ducts which promotes mold growth. Mold in your ducts can be a nuisance, or even worse, for your health.

Other AC Problems

In addition to those main issues that can happen from an air conditioner being run without a filter (or at least a clean enough one), other negative results are possible.

  • Higher energy bills
  • Frozen evaporator coils
  • Air not getting cooled sufficiently
  • Damaged compressor
Running AC without Filter like these can damage your home’s air conditioning system.


Running an AC without a filter can lead to big problems. Without anything to stop the dirt and debris from traveling through your home’s cooling system, the parts inside are going to be affected. They may get covered in dirt and grime and completely stop working altogether. You may need to have certain parts repaired or replaced. You may need to have your entire HVAC system replaced.

Either way, the cost of making sure you have a clean air filter in place is much, much cheaper than all the destruction not having one is likely to cause.


Dirty filter, almost as bad as running AC without filter

The keys to changing your air filter are:

  1. Make sure you have the right size of filter and that you install it in the correct direction
  2. Know how often you need to replace your filter

Knowing what filter you need and which way it goes can be very easy. Simply look at the filter that is already in your AC without completely removing it. Note down the size of the filter. For example, it may say 10×20, 16×24, 18×30, or another set of numbers.

Also, filters vary in depth. While most common filters are 1 inch thick, some are as deep as 6 inches.

Then you need to check for which direction the arrow is pointing. When you replace this old filter with a new one, simply make sure the arrow on the new filter is pointed in the same direction.

How often you need to change your AC filter depends on a few factors. Many people find they need to replace their air filter every 6-8 weeks. You will want to replace it more often if any of these conditions apply to you:

  • Pets in the home
  • Many people in the home
  • People who suffer from allergies
  • People with respiratory illnesses

If you have a permanent AC filter, you need to remove it to wash it regularly. Be sure to note which direction the arrow is pointing on that filter before completely removing it. You can use a permanent marker to draw on your system the direction of the arrow so you will never be left wondering.

Clean it with a hose until all the dirt and debris are gone. Dry the filter before you reinstall it.


Running an AC without a filter may be okay to do for only a matter of hours without serious problems occurring. If you feel like you need to run the air conditioner without a filter, then you should have time to run to the store for a replacement filter.


If you have any questions about your air filter or anything else about your home’s cooling system, call the Corpus Christi AC experts at Tommy Cool Air at 361-371-7538.

We are happy to troubleshoot and fix any problem you are having with your AC.

Tommy Cool can also provide professional maintenance service on your home’s entire cooling system. Having us come out to do a thorough check of your system can help us find and prevent any potential problems and breakdowns from occurring.

Tommy Cool Air technicians are qualified to service any type of air conditioner or cooling system. We provide 24/7 service to the Corpus Christi area and deliver friendly, quality service at a fair price. Read reviews from people across Corpus Christi who recommend Tommy Cool!

Call Tommy Cool at (361) 371-7538 and let us how we can help you today!

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