Water can evaporate inside a freezer or a fridge for a few reasons that go beyond just atmospheric pressure.
Firstly, even at low temperatures, some water molecules have enough energy to escape the liquid phase and enter the gas phase. This phenomenon occurs because water molecules are constantly moving and colliding with each other. While the average energy of the molecules is lower in colder conditions, individual molecules can still gain enough energy through these collisions to evaporate.
Another important factor is the humidity level inside the fridge or freezer. If the air inside is relatively dry, the evaporation process will happen more readily as there are fewer water vapor molecules in the air to saturate it. This creates a situation where water from spills or open containers can turn into vapor and diffuse into the air.
Additionally, the constant operation of the fridge or freezer’s cooling system can lead to drier air within the appliance. When the compressor runs, it can remove moisture from the air, further promoting the evaporation of water.
Lastly, ice formation involves complex physical changes, and the presence of ice can contribute to the evaporation of any moisture in the area. As ice sublimates (turns directly from solid to gas) in the freezer, it can also lead to further drying of the air, allowing liquid water to evaporate more easily.
In summary, while atmospheric pressure does play a role, the movement of water molecules, humidity levels, cooling effects, and sublimation all contribute to the evaporation of water inside a fridge or freezer.