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How Do Ice Makers Work? – Explained by Types

Ice makers use built-in thermostats to monitor and maintain the temperature in the molds. Once the water valve is opened, the water starts filling the ice molds for the next 7 seconds and closes by itself. Ice cubes freeze gradually and, once the ice builds up and the temperature dips to a particular level, the thermostat will close a switch in the electrical circuit and start warming up the heating coil and the bottom of the mold. Once the mold is warm enough, the ice cubes will start slipping off the surface.

More information about how do ice makers work and the differences between the ice-making process of a commercial ice maker, a regular refrigerator ice maker, and a portable ice maker are listed below.

How Do Commercial Ice Makers Work?

How Do Ice Makers WorkIce makers use four essential components: a compressor, a condenser, an inlet valve, and an evaporator. To start the ice making process, the machine should be hooked to the plumbing line that supplies it with fresh water and to the electrical circuit that powers it up. This automates the process of ice making as the ice tray (connected to a set of coiled heat exchanging pipes) is instantly refilled once a batch of ice cubes is extracted.

When the switch is turned on, the machine starts pumping water from a collection sump and directs it towards the ice tray. Then, the compressor fires up and compresses low-pressure vapor into high-pressure vapor, which is then delivered to the condenser. Next, the condenser will take that high-pressure vapor, route it into its coiled pipes which are near the unit or on its exterior. This will dissipate the heat as the high-pressure vapor transforms into high water pressure.

Then, an inlet valve will release the pressure of the high-pressure coolant, creating vapor again. The refrigerant moves to the evaporator where the heat exchange happens. An evaporator is usually a metal rod that is cooled by the low-pressure coolant which then makes the interior of the machine and the ice tray cold.

During this process, the water gradually freezes and turns into clear ice. Several minutes afterward, a solenoid valve (that is connected to the heat exchanging pipes) is activated, which makes the refrigerant change the direction and cycle back to the evaporator. The ice tray and heat exchanging pipes start heating up rapidly, which loosens the ice cubes and makes them slide down. Some ice makers come with cylinder pistons that eject the cubes out of the tray once the tray starts warming up.

How Do Refrigerator Ice Makers Work?

Regular freezers and refrigerators come with ejector blades and shut-off arms that scoop the cubes up and out and push them towards the collection bin that is located right underneath the tray. When there are no more ice cubes left in the molds and the shut-off arm reaches the lowest position, the water valve is instantly activated to begin a new cycle. If there are any ice cubes stuck in the way, the machine will fill only a part of the tray with water.

The Difference Between Commercial and Refrigerator Ice Makers

The difference between a commercial ice maker and a refrigerator ice maker is that the latter freezes whole pockets of water. Commercial ice makers freeze ice cubes layer by layer, from the inside out, making sure the cubes stay clear and crack-free.

How Do Portable Ice Makers Work?

How Do Portable Ice Makers WorkA portable ice maker is not connected to a water line and thus, filling the water reservoir is a manual task. A water filter pumps the water via a hole in the bottom of the reservoir up to the ice tray that is located on top of the machine. When the cycle starts, the ½-inch prongs on the heat exchanger are submerged into the water.

Prongs get cooled down quickly, which encourages the formation of ice cubes within minutes (6 on average). When the cubes are ready, the spikes start heating up, making it convenient for the cubes to slide off and roll down into the ice bin, right above the water reservoir. Portable nugget ice makers do not keep stored ice frozen as commercial ice makers do. If all the cubes stored in the ice collection bin are left unused, the water from the melted cubes will go back into the water reservoir and turn into ice again.


Ice making is a tale as old as time. However, ice making techniques have become more sophisticated over centuries, and we couldn’t be happier! Now you know everything about how do ice makers work – whether it be a commercial or portable machine, while your freezer/refrigerator works on a similar, yet not quite the same, principle.

About Aaron Walters

Aaron Walters is a code writer by day, and a cocktail enthusiast by night. Once he realized that high-quality ice is equally important as other ingredients, he started researching ice machines of all types and sizes. Icemaking101.com is a library of researched topics regarding all things ice he made along the way.

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