What is the difference between frost free and auto defrost in a freezer?

Answer 1

A frost-free freezer regulates the temperature at a level to prevent the build-up of too much frost - so that it should never need defrosting by the user. The internal temperature is low enough to keep the food frozen - but not low enough to allow a build-up of frost. An auto-defrost freezer allows a layer of frost to build up over time - when it reaches a preset level - the appliance raises the temperature enough for the frost to melt (but maintains the working temperature to keep the food frozen).