How Do Portable Ice Makers Work?

How Does an Ice Maker Work?

Making ice is something we’ve come to take for granted in the last hundred years or so. Just fill a tray with water, stick it in the freezer, wait 30 minutes or so and, bam, ice! Whether you do it manually, or rely on the convenience of an automatic ice maker in your refrigerator, the process is pretty much the same.

Except when it’s not. There are actually some variations in the methods used to make ice, especially when it comes to commercial ice production. Clear ice makers, for example, don’t freeze whole pockets of water at a time like your refrigerator ice maker does. Instead, they lay down thin layers of water, freezing from the inside out, sort of like icicles form, so that there are no microscopic cracks from escaping particles and the ice stays clear.

A portable ice maker works a little differently, too compared to commercial ice makers. So how does a portable ice maker work exactly? Instead of filling an ice mold with water and then putting the ice mold into a freezer, a portable ice maker freezes the water directly, so it takes much less time to complete a batch of ice. Here’s a detailed explanation of how an works.

1) Water is added into the unit’s water reservoir, up to the fill line. Because these units are meant to be portable, they’re not connected to a water line and must be filled manually. That means you just pour the water directly into it with a faucet, bucket, jug, etc.

2) The water is pumped via a hole in the bottom of the reservoir through a water filter and up to an ice tray at the top of the unit. Any overflow spills back into the reservoir.

3) When the refrigeration cycle begins, the 1/2-inch prongs on the heat exchanger are lowered into the water of the ice tray. These submerged spikes get cold very quickly, and ice begins to form on them in a matter of minutes.

4) The size of the ice cubes depends on how long the prongs are left in the water. A longer cycle means thicker pieces of ice. Small ice usually takes about 6 minutes, while large ice is about twice that, though freezing times can be affected by the ambient temperature and how long the unit has been running.

5) When the ice has reached the proper size, the ice tray empties any remaining water back into the water reservoir. At the same time, the heat exchanger reverses itself and the spikes start to heat up – just enough so that the ice pieces slide off the prongs and tumble into the ice bin that’s above the water reservoir.

6) A second sensor on storage basket monitors the amount of stored ice, and shuts off the system if it gets too full.

Here are some important tips on how to use an ice maker:

A portable ice maker is not a freezer. Once the ice is made, it will not keep stored ice frozen. Either use it right away, or move it into your refrigerator’s freezer to keep it from melting.
Ice that melts in the storage bin will drain back into the water reservoir for reuse.
Because the freezing element of a portable ice maker is placed directly in the water, it can make ice much more quickly than a regular freezer, which lowers the air temperature.

Learn More about the Refrigeration Cycle

The vapor-compression refrigeration cycle used in a home ice maker is the same that is used in an air conditioner, refrigerator or freezer. It’s based on the scientific principle of thermodynamics, which explains the transfer of heat during evaporation. When a coolant, like refrigerant, transforms from a liquid into a gas, it is able to absorb the surrounding heat during the transformation. The coolant then releases that heat when it changes back into a liquid.

A refrigeration system has four main components that facilitate the transfer of heat via the coolant. These components are:

Compressor – compresses the coolant, turning it into a hot, high pressure gas
Condenser – a set of coiled pipes on (or near) the exterior of the unit that dissipate heat as the coolant transforms into high water pressure
Expansion Water Valve – also known as an inlet valve – releases the pressure on the coolant, turning it into vapor again and lowering the temperature of the coolant
Evaporator – another set of heat-exchanging pipes on the interior of the unit that make the interior of the unit cold

Here is a diagram of how the system works in principle:

In a freezer or refrigerator, the cold air produced by the evaporator is collected in the unit’s insulated interior. In an air conditioner, the cold air is distributed throughout the room by means of a fan. In a portable ice maker, however, the cold produced by the evaporator is concentrated in the prongs attached to the evaporator, so that ice forms on them when they are immersed in fresh water.

Keep in mind that those prongs can get very, very cold – avoid touching them when the unit is plugged in and operating!

Troubleshooting a Portable Ice Maker

Several mechanical systems work together in a portable ice maker. Problems in any one of them can lead to underperformance, or outright failure, of the unit. Here’s how to diagnose operational problems and try and correct them.

Power supply – if the unit won’t turn on, make sure if it is plugged into an outlet of the proper voltage and the circuit breaker is functioning. If the problem persists the unit will need to be repaired by a qualified electrician.
Broken pump – If the water pump in an ice maker fails, no water will be moved from the water reservoir to the freeze tray. Replacing the water pump should correct this problem.
Leaking water – If the pump is operating but no water is reaching the freeze tray, or there is water leaking from the unit, likely causes are probably a blocked or broken hose in the pump system.
Leaking coolant – If the system appears to be operating normally, but ice doesn’t form, there is probably a coolant leak. You might actually see an oily substance leaking from the unit. This needs to be repaired by a qualified technician.
Insufficient ice – If ice produced is too small, it may be the ambient air temperature is too warm, the water supply is low, or the water placed in the reservoir is too warm. Try using chilled water and see if it helps. If the problem persists, there may be a small coolant leak that is affecting system performance. This needs to be repaired by a qualified technician. Likewise if ice is only forming on some of the evaporator prongs.

If you experience other problems with your NewAir countertop ice maker, you should contact our customer service center for assistance. We have a generous 365-day return policy and we’re happy to help you resolve your problems, so you can continue enjoying plentiful fresh ice whenever you need it.