How Do Commercial Ice Machines Work?

Have you ever wondered how a commercial ice machine manages to make all those perfect ice cubes so quickly? We have. While a domestic machine seems to work logically — at a rate of about a very small bag of ice every three hours — commercial machines create copious quantities of perfect ice very quickly, so how do they do it?

Let’s First Talk Briefly About the Refrigeration Process

The actual science behind freezing water doesn’t change much, except that commercial machines have more powerful compressors and refrigeration cycles. The refrigeration process applies to all gas-filled coolers — that is, all modern electric fridges and freezers. Refrigeration works because of the heat absorption of evaporation. The refrigeration cycle forces a suitable gas to condense into a liquid and then evaporate again. A refrigerant — a.k.a. a gas that has effective heat transfer properties when it changes state — passes through a compressor, raising the pressure and temperature. Next, the compressed gas is forced through another condenser, made up of narrow tubes that convert the compressed gas into a liquid. Then the liquid passes through an expansion valve and chamber called an evaporator, where the liquid evaporates, changing back to gas. This evaporation process is what provides the cooling effect, as heat is absorbed during evaporation, and the surrounding area is cooled. This is how refrigeration occurs. In a commercial ice machine, the evaporation chamber directly cools the water, which is running slowly into ice trays, filling them with ice.

How the Ice Is Made in a Commercial Ice Machine

The special feature of a commercial ice machine is the way water is directed onto the super-cooled evaporator to effectively and rapidly make ice. The majority of commercial ice makers use a vertical ice tray. Water is poured slowly over the vertical tray so it freezes in layers. This layering is the key to making clear ice versus the cloudy ice often made in our ice trays at home. When ice freezes in small layers, it remains clear because it is mostly free of trapped air. To release the ice, ice machines either use re-directed heat from the compressor or a mechanical trigger. The quantities of ice made are possible because of the size of the refrigeration cycle, the direct freezing process and the special compact design of the vertical ice trays

What is the Basic Construction of a Commercial Ice Machine?

All commercial ice machines employ a refrigeration cycle as described above, where the evaporation chamber is directly aligned with the ice tray. They have a water inlet, a reservoir to ensure constant controlled flow and a drainage point for overflow. A heat operated or mechanical release mechanism releases the ice cubes once they are fully formed. Sensors are fitted to automate parts of the process or provide warning functions. A collection point and storage bin or an on-demand dispenser are fitted depending on the type of ice machine. To improve efficiency and operation, the compressor and condenser require some cooling. Most commercial ice machines are air-cooled while some are water-cooled. Water-cooled machines are slightly more expensive but reduce the operating temperature, which can help machine efficiency in hot environments and reduce air-conditioning expenses. Water-cooled machines are also slightly less noisy. Some machines include a pump to increase the amount of water available or to pump from a static water source.  

Qualities of a Commercial Ice Machine

 

• Quantity of Ice Produced

  The design capacity of a commercial ice machine is determined by the amount of ice a machine can produce over a 24-hour period. Very small commercial machines produce around 50 pounds of ice per day, similar to home ice makers; large machines can make several hundreds of pounds of ice per day. Very large ice machines are capable of thousands of pounds of ice per day.  

• Type of Ice Produced

  Commercial ice machines produce three main types of ice: cubes, nuggets and flakes. To make matters a little more complicated, each manufacturer has a slightly different name for these types of ice. Cubes are available in a variety of sizes: small, medium or regular and large or full cubes. Full cubes are usually 7/8-inch cubed. Large cubes don’t melt as quickly, so they’re very suitable for serving restaurant drinks in hot conditions or for use in chilling buckets. Half cubes are 3/8 inch x 7/8 inch squared. Ice nuggets have the largest variety of names and shapes. Usually called nuggets, they are also known as round cubes, cubelets or bullet cubes. Cornelius calls them chunklets, and Ice-O-Matic calls them pearls. Scotsman trademarked their nuggets as “Chewable Ice Cubes” since people love to crunch on their small shapes while drinking. These are great for cocktails, juices, iced coffee and many other beverages. Nugget machines use slightly less water and power than cube machines. The smaller size permits more ice quantities for the same apparent volume in glasses, slightly improving drink to ice ratio and improving profits. Storage is also more efficient. Nuggets do melt quicker than full ice cubes, watering down drinks faster and not lasting as long. Flakes or crushed ice are used mainly in food storage such as fish displays and medical applications. They can also be used in ice-blended beverages.  

• Type of Structure

  Ice machines come in a range of shapes and functions designed to meet the different applications they are intended for. Under-counter ice machines, as the name indicates, are around 30 to 35 inches (70 cm-85 cm) tall, allowing them to fit neatly under a countertop. Compact ice machines are smaller units that provide better use of space for a small kitchen area such as in a food truck. The overall capacity is slightly smaller than freestanding machines, but they are still capable of producing quite large amounts of ice. Modular ice machines are popular for commercial applications because heads and bins are sold separately. The ice head is the production part of an ice machine, and the ice bin is the storage part. Ice heads may also be attached to different dispensing mechanisms. Self-contained ice machines are stand-alone devices that perform all the ice machine functions together. Ice dispensers are on-demand units that provide ice for filling ice buckets or refilling ice storage bins in different locations. Ice machines may be fitted, meaning they are connected directly to the plumbing and electricity and not movable, or they can be standalone where the water and electricity sources are plugged in so they can be disconnected and moved.  

• Features

  The different features available for ice makers are what distinguish the various models. Automatic sensing functions are available to automatically refill ice storage bins in freestanding units. Some machines provide a selection of different ice cube sizes; however, molds are usually only one shape. A variety of different cleaning and filtering features are available in different models, and later models have improved self-cleaning and flushing features. Diagnostic functions may be provided to indicate when a part fails or when regular maintenance is required. Advanced controller options provide for pre-programming of ice dispensing functions to match demand.  

• Performance

  Performance comparison of ice machines is not just in the capacity of ice they make but can also be measured in the water usage and electricity usage per 100 pounds of ice. Both these figures should be considered along with the overall ice capacity when comparing models. Water and electricity usage per 100 pounds of ice can vary significantly from under 5 to over 12kW of power, and from under 12 to over 35 gallons of water to make the same 100 pounds of ice. With costs of utilities and current environmental concerns, energy rating is definitely something to consider when comparing machines. A low-cost machine with a high output is suddenly not so cheap if it uses double the water and electricity. Here are some of our recommended models:   Scotsman Ice Machine A leader in ice technology, Scotsman has been making commercial ice machines since the 1950s, with the origin of the Scotsman ice making brand actually dating back to 1921. Scotsman has a range of over 300 ice machines, with authorized distributors and service agents in over 100 countries. For Scotsman, ice is their business; they concentrate solely on developing excellence in ice machine technology. Their policy is to get to know everything about the different ice making needs of their customers and provide effective solutions for them. This has led to many patented systems, such as WaterSense and Eclipse. Their latest technology, Prodigy, improves efficiency by operating at much lower electricity and water consumption rates for the same quantities of ice. Scotsman believes in quality, and for this reason, they were the first commercial ice machine manufacturer to receive ISO9001 certification. Scotsman products appear to have one of the best cost versus quality ratios, meaning that the type of design they provide is a very good value for the money. Scotsman has one of the largest ranges of machines. Currently their highest-rated machines can produce around 2,600 pounds of ice in a 24-hour period.   Hoshizaki Ice Machine Creators of Japan’s first fully automatic ice maker, Hoshizaki now has headquarters in Europe, Asia and the USA, with vendors in over 100 countries. They specialize in commercial ice machines and commercial kitchen refrigeration equipment. Hoshizaki’s excellence dates back some 70 years; continued research has helped them establish themselves as one of the industry’s leaders in ice making technology. Hoshizaki’s focus is on clean, quality ice, so their features include proper filtration, self-cleaning and a double flushing system. Efficiency and durability are their next highest priority, and the high-quality engineering that goes into these products ensures they succeed. Hoshizaki’s range includes a patented evaporator and design features such as CycleSaver, which improves efficiency, and the EverCheck control board that improves diagnostics. Partnering with Danish refrigeration specialists Gram Commercial, they have improved their style and innovation in ice makers. The Hoshizaki range’s best feature is its patented stainless-steel evaporator plates, which have extremely good durability. The machines perform well in all conditions too, where other machines can exhibit reduced performance with increasing temperatures.   Top-of-the-range engineering does come with a cost, and these machines are comparatively toward the top end of the price range for an ice maker. Hoshizaki has some 200 different machines within a range of 45 pounds up to just over 500 pounds, including all types of shape and function. They are one of the few companies to make a crescent-shaped pure, clear ice cube.   Manitowoc Ice Machine One of the most popular U.S. brands, Manitowoc Ice has been producing ice machines since the 1960s.   The Q-Series provided the first in aesthetic designs, QuietCube provided quieter remote condenser technology, and the S-Series was the first to comply with the new sanitation requirements of NSF/ANSI 12-2003. Manitowoc Ice machines pride themselves in their extensive automation and advanced technology. The Indigo series provides “intelligent diagnostics,” a complex computer controller that makes maintenance and operation foolproof. Their high-tech designs also host a range of easy cleaning and maintenance functions. Many parts can be removed without tooling, making replacement and cleaning very quick and efficient. One of the most automated and advanced brands with extensive features and aesthetic design, Manitowoc ice machines are typically higher priced than comparable machines for the same ice quantities. Their physical size is also slightly larger than most, which can be difficult in a confined space. Manitowoc has around 200 different machines with a range of around 65 pounds up to a whopping 3,300 pounds of ice per 24-hour period.     Cornelius Ice Machine Cornelius is a leading manufacturer of drink dispensers, coolers and ice machines. Relatively newer in the market than some of their competitors, Cornelius has wasted no time coming up with some innovative designs. Their experience with commercial machines and customers in the beverage industry has allowed them to quickly come up with a practical and extensive range of machines. They provide free-standing, modular and under-counter machines for cubes, nuggets (called chunklets) and flakes. Their range provides for a selection of machines producing from 100 pounds to 2,000 pounds per 24-hour period. The philosophy behind Cornelius is ice, plain and simple. They provide all the quality of other ice machines but without the complicated add-ons. And with over 50 years in the business, they know what they are doing when it comes to ice. The reason they provide simpler machines is that both manufacturing and maintenance costs can be reduced when simple operating principles are adhered to. Where no fancy functions are needed, these machines are perfect, being more reliable and slightly cheaper than comparable models.   Iceomatic Ice Machine  Iceomatic pays attention to the important features of an ice machine, and they were the first to introduce bacteria-reducing AgION technology. Not only do Iceomatic machines promise and generally succeed in providing “the most ice for the price” (their sales slogan), they also currently provide the longest warranty — seven years — which backs up their promise of high durability. The warranty is only valid if an approved Iceomatic water filter is used and replaced according to their specifications. Filters ensure that parts are kept clean, and clean ice is formed more efficiently.

Ice Machine Choices

If you’re researching the different types of ice machine, first determine what your needs are for capacity, energy efficiency, control features, diagnostics, dispensing or storage, and space. Then look at the availability of options and service in your price range.