Y does the icebox get all frost up after lowering the temperature?

Question

Y does the icebox get all frost up after lowering the temperature?

Answer 1

Freezing draws moisture from the air, the water in ice cube trays, and the food in the freezer and it collects as ice on the walls of a non-frost-free freezer.

Answer 2

When you lower the temp, the temp eventually equals out to the dew point. When this happens, moisture in the air condenses (called dew). If it is below freezing, the dew freezes to become frost.