Technicians often confuse symptoms of a refrigeration system that has a frosted evaporator coil with a system that is severely overcharged with refrigerant. Hopefully, this article can clear up any misconceptions between these two system problems.
Let’s look at what happens as frost starts to accumulate on an evaporator coil. Frost on an evaporator coil will prevent the correct amount of airflow across the coil. Anytime the evaporator coil sees reduced airflow across its face, there will be a reduced heat load on the coil. Low airflow and less heat load across the evaporator coil can cause much of the refrigerant in the coil to remain a liquid and not vaporize as fast. Some liquid refrigerant may travel past the evaporator coil, through the suction line, and eventually get to the compressor. Compressor damage will soon occur from compressor flooding and/or slugging.