What’s the best way to make ice at home? Most people would probably say their freezer. It’s there, it’s convenient, and his usually has an automatic ice maker built right in. They’d say that, but they’d be wrong. If you want a lot of ice, enough so that you never run out, then you should ditch your refrigerator ice maker and get a portable ice maker instead. Portable ice makers produce more ice in less time than refrigerator ice makers, a lot more ice. Approximately 23 and a half pounds more and it all has to do with the way each one makes ice and the physics behind each machine.

Principles of Heat Transfer

The exchange of thermal energy between different physical systems is known as heat transfer. Heat transfer occurs whenever two systems with unequal temperatures come into contact with one another. Heat flows from the warmer system into the colder system until the two are in equilibrium. There are three types of heat transfer: conduction, convection, and radiation. Conduction occurs when two objects of dissimilar temperatures come into direct contact with one another. Convection occurs when the heat from an object travels through a system through the mass movement of fluids such as gas or water. Radiation occurs when photons from a high energy source collide with low energy objects. Radiation plays a considerable role in melting ice, but a in ice formation. Ice formation happens when heat is transferred from water into a colder system it’s coming into contact with. In portable ice makers, it’s the freezing prongs. In refrigerator ice makers, that system is the air in your freezer.

How Refrigerator Ice Makers Work

Your refrigerator’s ice-making cycle begins when the machine sends an electrical signal to the refrigerator’s water valve that opens it and releases water into a specialized mold in your freezer. The valve is normally open for about seven seconds, just enough to fill the mold, which usually holds enough room for 6-9 ice cubes. Once the mold is filled, the valve shuts off and the water slowly freezes through the process of convection. Because the freezer is being filled with cold air from the compressor, it’s a lot colder than the water in being poured in from the rest of the refrigerator, which is usually around 50°F. The difference in temperature initiates a heat transfer. The air in immediate contact with the water’s surface warms up and expands. As it does, it draws in more cold air to replace it, which gets warmed in turn, and so on.

Air is a notoriously bad heat conductor. Its particles aren’t attracted to each other as strongly as particles in solid objects so as heat enters them, they take a long time to collide with other particles and pass the heat on. For this reason, the heat transfer process is pretty slow in your freezer. Even at temperatures of 0°F, the recommended average temperature, it takes water over an hour to freeze into ice. Once it has, the rest of the process is fairly straightforward. Automatic ice makers have a built-in thermostat that monitors the water’s temperature while it in the mold. Once it’s reached a preset level, approximately 9°F in most cases, it actives a heating coil under the ice mold that breaks ice free of the mold. Then a rotating ejector blade swoops down and scoops the ice out into an ice tray below, where it’s stored until you decide to use it. Then the circuits send another signal to the water valve and the whole process starts over again.

How Portable Ice Makers Work

In order to speed up the ice making process, portable ice makers make ice cubes using conduction instead of convection. Once the pump has brought the water up from the reservoir to the ice case, a rotating plastic tray where the ice is formed, a set of metal prongs is lowered down into the water. The prongs are connected to the compressor’s evaporator coils, which keeps them extremely cold. Because metal is an excellent heat conductor, the prongs begin freezing the water almost immediately. The heat gets drawn into the prongs and picked up by the refrigerant in the coils, which is pulled back down into the compressor, heated, and then cooled again as it passes back up into the coils again. This cycle of cooling keeps the prongs freezing cold at all times and the ice builds up around them in layers.

Once the ice reaches a certain thickness, the ice tray pulls back and the prongs switch from cooling to heating. This loosens the ice’s grip on the prongs, causing them to pop off and slid down into the ice try below. Any left over water is drained down into the reservoir and becomes part of the next batch.

In a NewAir portable ice maker, this process takes approximately 15 minutes. That’s 36-48 cubes every hour, 28-50 pounds of ice per day. Here’s how they break down compared to ice makers from leading refrigerator manufactures.

NewAir AI-100 Ice Maker NewAir AI-215 Ice Maker GE Top Mount Ice Maker GE Cafe Side By Side Ice Maker Samsung Ice Maker
Ice Making Cycle 15 Min. 13 Min. 1.5 Hours 1.5 Hour 1.5 Hours
Ice Cubes per Cycle 9 12 6 7 9
Amount of Ice Per Day 28 Pounds 50 Pounds 3.5 Pounds 4.5 Pounds 4.8 Pounds
Ice Sizes 3 3 1 1 1


Twenty-eight to fifty pounds of ice is enough to fill a cooler. It’s enough for a party. It’s enough to make homemade ice cream or provide cool drinks for a sports team. It’s enough to ensure you never have to worry about running out of ice no matter how much you use. That’s something refrigerator ice makers can’t promise. They’re just not built to for large households or large parties with lots of people.


Though portable ice makers outperform ice makers in refrigerators in terms of ice production, they do have some limitations that are worth mentioning. The biggest is their inability to store the ice once it’s been generated. Portable ice makers aren’t refrigerated. All of their cooling power is concentrated in the evaporator assembly and the cooling prongs. Once the ice slides down into the ice basket, it begins melting. If it’s not removed, it will all drain back down into the reservoir and get sucked up by the water pump to form new ice cubes. In order to reach the ice maker’s full capacity, you’ll have to empty the ice into a cooler or place it in your freezer whenever the ice basket fills up.

Refrigerator ice makers also have access to a steady stream of water. Portable ice makers don’t. They have to be refilled manually whenever they run low. Because they’re not refrigerated, portable ice makers are also more susceptible to external temperatures. Placing them in high heat or direct sunlight can slow down the ice making process, reduce ice cube size, or cause the ice in the ice bucket to melt faster. They operate best in cool, shady spots.

Who Are Portable Ice Makers Right For?

Portable ice makers are designed for people who love ice and use ice. They’re made for large households, hot climates, and people who entertain. They’re made for people who want ice immediately, whether they’re sitting in their living room, on their patio, or on an RV camping trip. They’re for people who are tired of the hassle and expense of buying large ice bags. Portable ice makers provide flexibility and convenience that can’t be matched by refrigerator ice makers.


Learn More About NewAir Portable Ice Makers


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