Short-Cycling: Your air conditioner is supposed to cycle on and off occasionally throughout the day, but a dirty air filter can cause those cycles to become more frequent than they need to be.
Freezing Up: A good, clean air filter allows air to flow freely out of your unit. A dirty air filter restricts the flow of cold air, causing it to build up inside the air conditioner and lower the internal temperature. Given enough time, that buildup of cold air can eventually cause ice to form on the coils.
Uneven Cooling: Even if it’s not enough to cause freezing, that restricted airflow isn’t good for your air conditioner’s cooling power.
Allergen Buildup: If anyone in your home suffers from asthma or respiratory allergies, it’s especially important to keep the air filters clean. A dirty filter can cause allergens to build up in your duct system, and they’ll linger there for months.You might even end up with a mold problem in the ducts.
General Wear and Tear: Air conditioners just last longer if they’re maintained properly. A good air filter helps to stop dust and dirt from building up on all of the unit’s internal components; a bad one will cause additional wear and tear that can lead to serious maintenance issues down the road. You may end up having to replace your air conditioner a year or two sooner.
Reduced System Efficiency: An A/C unit with a dirty filter will use much more power to cool your home
