Frost Free Refrigerators
Frost comes from moisture in the air that comes in contact with the cold generated by the evaporator coils. It condenses down to ice that collects both along the evaporator as well as inside the food compartments. Over time, more moisture comes in contact with the freezer area and the ice accumulates into large chunks.
Back in the day, freezers would frequently suffer from a build-up of frost inside the freezer walls. These chunks of ice would routinely need to be chipped and dug out of the refrigerator in order to free up lost space and rescue encased leftovers. Thankfully, modern refrigerators usually come with a "frost free feature", which eliminates that hassle.
Frost free refrigerators have a mechanism that will briefly heat up the area around the evaporator coils, melting any ice thatâ€™s attached itself. This mechanism operates on a timer, set to run approximately every six hours. Some more recent models of refrigerator have devices that actually monitor how often its doors are opened to determine when to activate. The mechanism will continue to apply heat until its temperature sensors detect the temperature rising above 32 °F, to which it then shuts off.