9 Consequences Of A Dirty Air Conditioner Filter – How To Avoid Them

Dirty air conditioner filters can reduce the airflow and cause ice to build-up on the coils. The reduced airflow can then lower your air quality, and cause motor burn out, higher electricity bills, and even allergy attacks and mold. Dust can also build-up on blower fans and ductwork, especially near the air vents.

Air conditioning is used by almost 90% of households, yet most of us don’t clean our air conditioner (AC) filters often enough. They then become clogged with dirt and toxins over time.

Fortunately, it’s simple to keep these filters in perfect condition. This guide will walk you through what happens to your AC when the filter is dirty, how to fix it, and the steps to clean and replace your filter.

9 consequences of a dirty AC filter

Below are all the bad things that happen if you keep running an air conditioner with a dirty filter.

1. Disrupted or reduced air flow

Reduced or disrupted air flow through your air conditioner is the first effect of a dirty filter.

While not cleaning or changing air conditioner filter components doesn’t bring more dust and pollutants into the air, they build up in the blower fans and air ducts instead, which disrupts and even reduces the air flow.

If the air flow to an air conditioner continues for a long period of time it will stop working properly, and eventually the whole unit will fail.

To make sure your AC continues to work the filters should be cleaned or replaced regularly. How often depends on your system and the recommendations in your user manual.

Solution:

• Unblock AC vents by removing any dirt, debris or mineral build-ups.
• Check your filter for any technical faults or damage.
• Clean the AC filter and vents.
• Check your user manual for the filter lifespan (digital copies are usually available on your brand’s website)

2. Frozen coils

Not cleaning your AC filter can cause it to freeze. Filters that are dirty stop the flow of cold air, causing dirt and debris to build up inside the air conditioner on the evaporator coils, this limits the movement of warmer air and ice begins to form on the coils.

As ice forms on the coils, the AC can freeze up entirely and cause water to pool near the unit.

Signs of frozen coils:

• Room is warm even though your AC is always running.
• Uneven cooling throughout your home.
• Presence of water (or water damage) from melting ice spilling out from the vents.

Solutions to the formation of ice on the coils of an AC due to freezing up:

• Turn off the unit and allow the ice to defrost for a few hours. While the AC is defrosting do NOT hack at the ice with sharp or heavy items, as this can damage your evaporator or condenser coil.
• Check to see if your air filter is clogged with dust and debris.
• Clean the filter or replace it if it is worn out.
• Contact your local professional to check out your unit if you have any concerns.

3. Poor Indoor Air Quality

An unclean or clogged AC filter will not perform as well as it should, this lowers the indoor air quality. The debris on the filter can cause the air conditioner to produce warm air or even reintroduce the dirt that was trapped by the filter back into your air.

The dirty AC filter and warmer internal air also provides a perfect home for bacteria, mold and fungi to grow in – leading to even poorer air quality and increasing the risk of health conditions.

To guarantee good (and safe) air quality, an AC filter needs to be cleaned regularly.

Solutions:

• Clean your AC filter (set yourself some reminders so it’s done regularly)
• Replace your filter if it’s still dirty or stained after cleaning.
• Invest in an air purifier (this is obviously optional)

4. Damage to AC components

Dust and other pollutants can put pressure on other parts of your air conditioner, limiting its lifespan.

When your AC system is forced to work harder due to a dirty filter, it suffers substantial wear and tear. And, in the end, this can lead to system failure long before any breakdowns or repairs on smaller components are required or expected.

Failure to clean the AC filter can cause damage to an entire air conditioner that typically starts with motor fan burn out from the increased workload and reduced air flow, as well as leaking duct problems, thermostat problems, clogged drains, and frozen evaporator coils caused by dirt.

Solutions:

• Replace damaged air filters.
• Contact a repair technician to assess the problem.

5. Higher electricity bills

Not cleaning the AC filter can easily result in a higher electricity bill. Dirty or clogged filters make your system more harder and use more energy to cool your home. As a result, your utility bill will increase.

Solutions:

• Clean and change the AC filters when necessary
• If there have been wildfires in your area clean your filter and vent immediately afterwards

6. Moisture and mold

Mold infestations can establish inside your unit if your AC filter is dirty.

Even high-quality HEPA filters in an HVAC must be cleaned and replaced regularly. If this isn’t done, moisture can build up in the duct system, creating a favorable atmosphere for mold to grow.

Mold infestations usually begin if the ducts get too damp.

Mold can swiftly spread throughout your home, making your family sick, especially if someone in your family is allergic to mold or is asthmatic.

Solutions:

• Clean your AC regularly to avoid mold growth.
• Consider installing an Air purifier that eliminates mold and its spores if you often have a moisture problem
• Physically removing any mold growths (you may need to use a vinegar solution)

7. Buildup on blower fans and ductwork

A buildup of dirt, dust, and pet dander can form on blower fans and ducts if the AC filter isn’t cleaned. It will no longer be able to properly filter the air, allowing dust and contaminants to enter the air conditioning system.

The working parts of an air conditioner, especially the fan motors and valves, become clogged with dust.

Solutions:

• Depending on your system, you should either replace or clean your AC filter
• Regular vacuuming of any visible dust in and around your unit
• Call a technician if you aren’t sure what to do

8. Allergy Attacks

Dirt and dust, as well as pet dander, can block your AC filters and vents if you don’t clean them. Allergens can build up in the duct system and then release into the air you breathe when the system is turned on due to clogged filters.

Allergy attacks can happen from breathing contaminated air, especially with dust, pollen or mold.

All of these things cause respiratory difficulties, but mold in particular can have a bad effect.

Mold exposure can cause symptoms such as a stuffy nose, wheezing, red or irritated eyes, and skin irritation. For this reason, if you notice that you and your family members are suffering frequent allergy attacks, then you should consider checking your AC system.

Solutions:

• Replace your dirty or damaged filter.
• Physically removing any other mold or bacterial infestations around the home.

9. Dust Near the Air Vents

There is a slew of consequences to not cleaning your air conditioning filter. Some of them are visible, while others are not.

If you don’t clean your air conditioner, you’ll notice increased dust at the air vents. When you compare these surfaces to other surfaces that are further away, you’ll notice a significant difference. It’s a solid sign that your air filter needs to be cleaned if the surfaces closest to the vents are dustier than others.

Solutions:

• Try hanging a clean white sheet close to one of the vents for 30 minutes, and if it turns gray, it means your AC filter is very dirty. 
• Clean or replace AC filter.   
• Create a maintenance routine.     

How to clean an AC filter

Here are all the steps you need to clean your AC filter

STEP 1: Turn off the air conditioning.

It’s always best to turn off any home equipment before inspecting it for problems or cleaning it. This also applies to air conditioners; make sure your system is turned off (at the mains) before inspecting the filter.

STEP 2: Access the AC filter and remove it.

You might not know where the AC filter is if you haven’t cleaned one before and because every air conditioner is different, looking at the ductwork is the only method to figure out where your filter is. However, before you can do anything further, you’ll either need to unscrew the vent cap or remove the filter using the release handle.

Keep in mind that an HVAC system will determine the exact location of the filter. Most models usually use the air conditioner filters behind the return vent.

Gently remove the AC filter while being careful not to damage it, and inspect it well.

Note: Check around to make sure you aren’t missing any filters during this maintenance. Some systems, especially in large homes, may have many return vents. For instance, if you have a Nordic Pure or Honeywell model. If you are unsure, contact your manufacturer to determine where the AC filter is located and whether your system has more than one.

STEP 3: Clean the filter of dust and grime.

Here, all you need to do is observe. Check if the AC filter is gray, discolored, or has visible surface dust. If that is the case with yours, then it means that the AC filter is dirty, and it‘s time to clean it.

The filter can be cleaned in a variety of methods, including:

1. Vacuuming 
2. Washing.

1. Vacuuming

Vacuuming is all that’s required for routine maintenance. To do so:

• Use a brush-free attachment to avoid damaging the filter. 
• Vacuum the entire length of the filter with the vacuum nozzle to remove dust. 
• If not, use a handheld vacuum or an attachment on the end of a good vacuum hose to vacuum it.
• When vacuuming, do not put too much pressure on the filter, or it will shred.

2. Washing

Simply wash your AC filter with water if you need a proper clean. To do so:

• Fill a big container halfway with room-temperature water.
• Mix in a small amount of ordinary liquid detergent thoroughly.
• Make sure the filter is completely submerged in the container.
• Allow the filter to sit for 20 minutes after moving it back and forth in the soapy solution.
• You should not use brushes and other abrasive equipment to clean the filter since they may cause damage; instead, use a hose to remove dirt and debris.
• Rinse it thoroughly with clean running water.

STEP 4: Allow the air conditioner filter to dry before replacing it.

Allow your AC filter to dry completely after washing it. It should be entirely dry after around 6 hours. Please do not dry it with a hairdryer because you may damage the filter.

STEP 5: Install the clean AC filter.

 Once your filter is completely dry, you can now install it. To do that:

• Simply place the filter back into its correct slot, ensuring that the arrows on its frame point away from you and toward the unit.
• Take care to observe the arrows printed on the filter’s side.
• All of the filter compartment components you opened should be closed and sealed.

How to replace an AC filter    

Below are all the steps you need to replace a dirty air conditioner filter.

STEP 1: Turn off the air conditioning.

Turning off the complete air condition system is critical before changing the AC filters. This is a very crucial step for safety reasons.

STEP 2: Locate your filter compartment and open it.

To access the filter, you may need to unscrew the vent cover, remove the filter using the release handle, or remove a door panel and unscrew a small metal slot where your filter is kept, depending on the type or model AC filter you have.

If you’re having problems finding your filter, consult the instructions provided by the manufacturer for your specific model.

STEP 3: Remove the filter you are using now.

Once you access your AC filter, remove it by gently pulling it out. Be careful not to tear or damage it.

STEP 4: Remove the new filter from its packaging.

Before installing the filter, double-check that you have the correct one and remove it from its packaging.

STEP 5: Place the new filter in the correct position.

Pay close attention to the arrows printed on the side of your new filter as you install it. The arrow indicates which way the air should pass through the filter. The arrow must be pointing away from you, just as indicated.

STEP 6: Make sure your filter container is closed.

Close and seal all of the components of the filter compartment after installing a new filter before turning your air conditioner back on. Create a cleaning routine afterward.

Frequently Asked Questions

Will an AC work if the filter is dirty?

An air conditioner will work even if its filter is dirty. However, a dirty filter will stop an air conditioner from working efficiently. A dirty filter will force an air conditioner to work harder to cool a home, resulting in more frequent repairs and, eventually, a shorter unit lifespan.

Dirty air filters reduce the efficiency of your air conditioner. It’s necessary to clean the AC filter for it to function correctly and to extend its lifespan.        

Is it better to run an AC with a dirty filter or no filter?

It is neither better to run an air conditioner (AC) with a dirty filter nor without a filter. Running an AC without a filter can lead to a condensation drain problem or even permanent damage to the entire AC system. On the other hand, dirty filters will make your air conditioner work inefficiently or become damaged.  

How often should AC filters be cleaned?

You should clean your AC filters once every month or according to the instructions on your user manual. If the AC is used frequently, is exposed to dusty surroundings, or has pets in the house, filters may require more frequent care. You should clean filters more frequently in dustier areas.

Based on how often you use your AC, the house dust condition, and pets’ availability, create a filter cleaning routine or consult your user manual.

Conclusion

There are various repercussions of not cleaning an AC filter regularly, but overall damage to the AC unit is a major concern.

Your cleaning routine may vary depending on how often you use your AC, the house dust condition, pets’ availability, and the type of filter your AC has. For instance, if your AC is always on and your home has a pet and is dusty, you may need to clean the AC filter more frequently.