The force that is generated by the rotation of the blower unit fan is what enables the air conditioner to suck in air into the system. Its rotation is also responsible for the force that pushes the air through the air duct system and into the home. This makes the blower unit fan an important part of the air conditioning system. Any problems with this fan is therefore bound to cause restricted airflow which will not only lead to evaporator coil icing, but also cause a drop in the efficiency of your air conditioning system. Here are the most common blower unit fan problems that may be to blame for the decline in your air conditioner's efficiency.
Dirty fan blades
The cupping of the blades determines how much air the fan can push or pull at any given time. The more cupped the fan blades are, the more air the fan can push into and out of the system.
When dirt accumulates on the cupped sides of a fan's blade, the cupping of the blades is usually reduced. In extreme cases, the accumulated dirt can take up so much space that the cupped sides turn into flat sides. As a result, even though the fan rotates at the same speed as before, the amount of air that it pulls or pushes through the system will be reduced. This will lead to restricted airflow, something that will then cause performance-reducing complications such as evaporator coil icing.
To solve this problem, remove the blades and then clean them with a damp cloth. If you don't want to go through the trouble of removing the fan, simply use compressed air to blow out any accumulated dirt particles. You can also prevent this from happening by replacing your air conditioner filters.
Bent fan blades
Bent fan blades can't rotate as smoothly as they are supposed to. In fact, they tend to knock on the fan's cage. This is one of the main causes of a noisy air conditioner. There is also the fact that bending affects the shape of blades, something that can then create a drag on the force that the fan generates. Both the fan's labored rotation and the distorted shape of the blades usually lead to a reduction in the rate of airflow within the system. And since the evaporator coil's efficiency is dependent on having sufficient airflow, this usually reduces the heat-exchange rate in this area. This eventually causes a drop in the overall efficiency of the air conditioning system.
Straightening the blades of the fan is an easy way to solve this problem. However, if the degree of damage is extreme, replacing it is a must. For more information, talk to a professional AC service.