Frost-free freezers can save you the hassle and mess of manual defrosting as they automatically help reduce the frost build up on freezer walls. Freezers without this feature typically require a manual defrost at least once per year or once the ice on the walls is more than ¼ inch thick. Manual defrosting requires you to turn off and unload your freezer, allow ice to melt, then clean up the melted ice, turn on the freezer and return frozen foods. However, no frost freezers can cost slightly more to operate as they work to monitor and automatically get rid of frost build-up.