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Can You Run Your AC Without a Filter for a Day?

I’m sure you’re reading this because your air filter is either worn out or destroyed, and you’re wondering whether you need to rush into replacing it. You’re probably asking yourself whether your AC will run without an air filter for at least a day.

Your AC can run for a day without an air filter, although this isn’t advised. If you run your AC without an air filter for too long, it could lead to further AC issues that could cost you to repair.

This article will detail several topics regarding running your AC without a filter, including signs your AC’s filter needs replacement, problems caused when you ignore replacing a damaged filter and how to replace an AC filter.

Signs Your AC Filter Needs Replacement.

Filters are an important part of your AC; therefore, they need to be maintained and replaced frequently. Typically a filter needs to be replaced after every 30 days to avoid any emergencies.

Below are the signs that indicate your AC’s filter needs replacing.

1. You’re Suddenly Getting High Electricity Bills

Determining the cause of your electricity bill spiking is challenging. During the summer, you expect your electricity bill to rise because your AC spends a lot of time running. However, if you notice that the bill is a bit too high compared to the previous summer, it could be because your AC filter is dirty and needs replacing. 

If your air filter is faulty less air passes through; therefore, it requires running for longer hours and using more power to cool the entire house.

2. It Takes Longer Than Usual To Cool the Air

When your filter clogs, it won’t supply the same amount of cool air as before. Therefore, it will take your AC longer to cool a room because the amount of cool air is reduced. It will probably take twice the time and power compared to a fully functioning filter.

It’s essential to spot a faulty air filter because the harder and longer the filter works, the quicker the entire AC wears out. Therefore changing your filter will, in turn, increase the lifespan of your AC.

3. Experiencing Frequent Allergy Attacks

Have you been getting allergy attacks more frequently? It’s probably because the air quality of your AC is low. Over time your AC accumulates a lot of dust that damages your air filter. Therefore, when you turn on the AC, instead of helping with your health, it worsens the situation because it’s spreading dust and allergens in the air.

If you suffer from allergies, be very vigilant about the condition of your air filter. Also, it’s advisable to purchase the Levoit Air Purifier if you suffer from allergy attacks. I recommend buying it because it’s highly efficient and has an activated carbon filter that captures allergens, dust, mold, and pet hair. 

LEVOIT Air Purifier for Home

Problems Caused by Ignoring AC Filter Replacement

Ignoring any problems with your AC unit, especially the air filter, isn’t advisable. Ignoring problems with your filter could cause the minor problem to escalate further into a major problem.

Some of the most common AC problems by ignoring filter replacement are:

1. Short Cycling

A filter normally cycles on and off during the day. If your air filter is faulty, it causes your air filter to cycle too often. Cycling causes your AC to produce some unpleasant noises, and if it occurs too frequently, it will cause the temperature to change annoyingly. Also, it will cause your AC to waste more energy, increasing your energy bill.

2. Uneven Cooling

If your air filter is dirty and clogged, the airflow from the AC unit to a different room is interrupted. It will cause different parts of your home to be hotter than others causing significant discomfort. Simultaneously, even though not the entire house is being properly cooled, your energy bill still increases.

3. Frozen AC

If you have a clogged air filter, cool air is restricted from flowing out of your AC unit. Over time, this cold air builds up and could even lead to your entire AC unit’s freezing. The AC freezes because the restricted cold air builds up inside the AC, lowering the internal temperature.

4. AC Breakdown

Maintaining the condition of your AC, including the air filter, will, in the future, increase the lifespan of your AC unit. A fully functioning air filter helps decrease the amount of dust collected on the AC units components.

A faulty air filter aids in the breakdown of your AC unit. It will make you have to replace your entire AC unit when you could have avoided all that by simply replacing your air filter the moment you notice it’s faulty.

5. Low System Efficiency

A faulty air filter reduces the efficiency of your entire AC unit. A faulty air filter causes your AC to run on more power. Also, it will cause your AC filter to not function to its full potential. Therefore, ignoring to replace your air filter will increase your energy bill in the long run.

DIY Filter Replacement

Replacing an air filter is an easy job. You don’t have to call a professional and ask for assistance in changing the air filter. Replacing your air filter for those who are allergenic will help reduce the attacks, and in general, help your AC run smoothly.

Follow the following steps to help you replace your air filter on your own.

  1. Locate your filter: Normally, the filter is placed either behind a wall-mounted air return grill or in a filter case on the AC’s blower compartment.
  2. Determine the size of your filter: To determine the filter’s size, you’ll need to check the existing filter and confirm the size. It is usually indicated on the filter’s side; for example, (20x20x1) the sizes differ. Note that before you take out the air filter, make sure first to check the airflow direction.
  3. Purchase a new air filter: Air filters are usually sold in packs. I recommend buying MervFilters 10x10x1 (remember to buy your size) air filter because it’s a Merv 8 rated filter that is compatible with almost every AC unit type.
  4. Remove the old filter: The filter is usually held by some spring; you’re going to have to detach it. Remove the old filter and dispose of it, but be careful not to disturb the intake air vent.
  5. Place the new filter in the same position as the old: Gently place the new filter, ensuring that the arrows point in the same airflow direction as the latter one. Return the string that holds the filter and close it.
  6. Return everything to its place: Make that after making the replacement to carefully return every part to its exact position. Do this to avoid future failure to avoid any future issues.

If you have any problems following the steps, you can use the following instructional YouTube video uploaded by ‘hoohoohoblin’ to understand better and navigate the above steps:

Final Thoughts 

Now that you know the dangers of running your AC without an air filter or with a faulty air filter, I’m sure you’ll go ahead and change that old air filter. If you weren’t sure when to change your air filter, now you know the signs to look out for to know your air filter needs changing. Hopefully, you won’t find replacing the air filter on your own such a hassle, thanks to the instructional steps and video.


  • Steve Rajeckas

    Steve Rajeckas is an HVAC hobbyist with an avid interest in learning innovative ways to keep rooms, buildings, and everything else at the optimal temperature. When he's not working on new posts for Temperature Master, he can be found reading books or exploring the outdoors.

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