What are refrigeration evaporator coils? A refrigeration evaporator coil is one of the most important parts of a walk-in cooler or freezer. It absorbs heat when warmer air is passed through a walk-in refrigeration system, thereby cooling the inside of the unit.
In other words, moisture from the air freezes onto the refrigerator evaporator coil—the cooling coils inside the freezer—and helps form a barrier that insulates against heat transfer. Airflow is also minimized as the passages inside the refrigeration evaporator tend to narrow because of build-up of ice. Each walk in freezer evaporator also features a defrost cycle that helps melt the frost or ice that gradually builds up in the refrigerator evaporator coil. Water that results from the melted ice is then drained from the freezer.