Evaporator Coil Icing: When The Air Handler Is The Source Of The Problem

16 May 2016
 Categories: , Blog


The air handler handles most of the airflow responsibilities in an air conditioning system. It pulls air into the air conditioner. It also forces air throughout the system. Anything that messes with the way it functions is therefore bound to cause air conditioning system airflow problems.

Restricted airflow and icing problems

In addition to reducing the efficiency of the air conditioning system, restricted air flow usually encourages the formation of ice on the system's evaporator coils. How does this happen? Anything that restricts the flow of air usually limits the amount of warm air available at the evaporator coil area. As a result, there is likely to be too-little-to-be-enough heat in this area to balance out the cooling effect caused by the change-of-state process of the refrigerant. This then creates the perfect environment for extreme temperature drops that not only cause moisture to condense, but also cause the formed moisture to freeze. This then leads to evaporator coil icing complications.

The following are air handler problems that usually lead to restricted airflow -- that then causes icing at the evaporator coil.

Motor problems

The motor at the air handler is responsible for the pull-and-push powers of the unit. Therefore, when there is a problem with the motor, the air handler won't be as effective as it should be when it comes to forcing air through the air conditioning system.

The use of an undersized motor will lead to an underpowered unit that won't be able to deliver the needed amount of air. Dirt accumulation in the motor can also interfere with the functioning of the motor by not only increasing the amount of friction that it has to overcome, but also increasing the risks of overheating – something that will reduce both its lifespan and its output.

Regular cleaning of the air conditioner's air filters is a must if you want to eliminate dirt-caused motor problems. As for an undersized motor, replacing it is the only solution.

Fan blade problems

The ability of the air handler's fan to push air through an air conditioning system heavily depends on the shape of its blades. Dirt accumulation on the depressed side of the blades can reduce the amount of air that they can push at a given time. And so can the twisting of the blades. Twisted blades can also cause the fan to wobble when the system is in operation. This will result in an ineffective air-driving process that will ultimately affect the overall functioning of the air conditioning system.

To restore proper airflow in your system, you will have to have the blades straightened. Regularly cleaning the blades will also help to ensure that the air handler is functioning at full capacity, something that will then reduce the risks of the coil icing that results from restricted airflow. Contact a commercial HVAC installation service for more help and info.


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