Undercounter ice machines are also called self-contained ice machines, because the ice maker and ice storage are all in one place. These machines are ideal for facilities looking to save space, or if you don't need a lot of ice per day. Keep in mind that not all of these machines will necessarily fit underneath every counter: so get your measuring stick out!
A standard counter is about 34" high, but of course this can vary. Note that the casters aren't included in the height of the machines; these will add another 6 inches. You can't put the machine itself on the floor because they need ventilation on all sides and a place to drain, but you could put the machine on wooden blocks. Special 2 inch casters are also available.
As with all ice machines, you will need to consider what kind of ice you want to make. Cubes are the most common, and can be used anywhere. Flake ice is typical for displays in grocery stores and with seafood.
Last but not least, you will need to consider the amount of ice you will need. It can be a big mistake to buy a machine that either produces too much or too little ice. Every establishment will vary, but on average a restaurant will need 1.5 pounds of ice per customer, a cafeteria will need 1 pound per person, and a hospital will need 10 pounds per bed.