How to Diagnose a Problem With an Evaporator Coil

It’s essential to diagnose the problem with an evaporator coil and fix it. For example, if your evaporator coil is frozen, it could be a sign of a problem. Keep reading to learn how to diagnose a problem with an evaporator coil.

What are evaporator coils?

The evaporator coil is one of the most critical components of an air conditioning system. Evaporator coils and used evaporator coils absorb heat from the surrounding environment and transfer it to the refrigerant gas. The refrigerant gas is then compressed and passed through the condenser coils, which release the heat into the surrounding air. There are four evaporator coils, including sheet-metal, tubular, plate-type, and fin-type coils. Sheet-metal coils are made of aluminum or copper and have a very low resistance to airflow. This makes them ideal for use in variable-air-volume (VAV) systems.


Tubular coils are made of copper or aluminum and highly resist airflow. This makes them ideal for use in constant-air-volume (CAV) systems. Plate-type coils are made of copper or aluminum and have medium resistance to airflow. This makes them ideal for use in either VAV or CAV systems. Fin-type coils are made of copper or aluminum and highly resist airflow. They are also ideal for use in either VAV or CAV systems.


What are some common problems with evaporator coils?

The evaporator coil can be affected by several problems. One of the most common problems is a dirty evaporator coil. This can happen if something gets caught in the coils, such as dirt, dust, or insects. If this occurs, it will impede the airflow and prevent the coil from cooling correctly. A dirty coil can also reduce the efficiency of the air conditioner and increase the amount of electricity the unit uses. Another common problem with evaporator coils is a leak. If a leak occurs, the refrigerant will escape from the coil. This can cause the air conditioner to stop working, and it can also increase the cost of operating the unit.

Lastly, if the evaporator coil freezes up, it can cause significant damage to the coil. Freezing can occur when the air conditioner runs for an extended period and the coil does not get a chance to thaw. Be sure to clean the evaporator coil regularly and keep it debris-free. This will help to prevent freezing and ensure that your air conditioner works properly.


How do you diagnose an evaporator coil problem?

When diagnosing a problem with an evaporator coil, it is essential to test the compressor relay and capacitor for proper operation. If either of these components is not working correctly, it can cause the evaporator coil to malfunction. To test the compressor relay, use a multimeter to measure the resistance across the two pins on the relay. The resistance should be between 0 and 1 ohms. If the resistance is outside this range, the relay is likely defective and needs to be replaced. To test the capacitor, use a capacitance meter to measure its value. The capacitance should be within 10 percent of its rated value. If it is not, the capacitor may need to be replaced.


You can also check to see any obstructions in the coil. You will need to remove the access panel on the side of the unit. Once you have done so, you should be able to see the coils. If you notice anything blocking them, use a vacuum cleaner to remove it. To test the airflow through the coil, you will need an infrared thermometer. The easiest way to do this is to remove the front cover of the furnace and point the thermometer at the coil. You should take a reading in both the supply and return ducts. If there is a significant temperature difference, it could be an indication of a problem with the airflow.


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