The term ice plant is used here to determine the production and storage of ice. The ice plant unit is the one that converts water into ice together with the associated refrigeration machinery, harvesting and storage equipment, and the building.

Ice plants are usually classified by the type of ice they produce; hence there are block ice plants, flake ice plants, tube, slice or plate ice plants and so on. Ice plants may be further subdivided into those that make dry or wet ice. Dry ice here means ice at a temperature low enough to prevent the particles becoming moist; the term does not refer in this note to solid carbon dioxide. In general, dry sub cooled ice is made in plants that mechanically remove the ice from the cooling surface; most flake ice plants are of this type. When the cooling surface of an ice-maker is warmed by a defrost mechanism to release the ice, the surface of the ice is wet and, unless the ice is then sub-cooled below 0°C, remains wet in storage; tube ice and plate ice plants are of this type.