Ice is one of the most important “foods” sold in restaurants. If you have ever run out of ice, you know just how important it is. Most ice shortage headaches are avoidable by proper equipment selection, sizing, and maintenance. Problems with continual service calls are also often avoidable with proper maintenance and the help of some new user friendly accessories available on some machines. This month, we will examine the types of ice makers and bins available and give some sizing guidelines and information about some new features for the equipment.
Cube, flake or nugget?
The first step in evaluating equipment is first to consider the type of ice you need and the kinds of machines that make it. The classic ice type for beverages is cube ice. Cube ice is clear and appealing for beverages.
Commercial quality cube ice differs from that made in ice trays at home in order to produce better quality and much higher rates of production.
Flake ice is the other main ice type. Flakes are ideal for rapid beverage cooling but tend to water down drinks too much for most customers. While flaked ice can be used in beverages, a newer “better” drink ice has been invented, sometimes called “nugget” ice. This ice can be thought of as compressed flaked ice formed into small cylinders. This ice is not as crystal clear as cubes but it is hard and slower to melt than flaked ice. The product is formed in an easy-to-chew sized nugget which is desired by many customers for beverages, especially in quick service applications.
The process of making nugget ice uses less water and significantly less electricity than producing cubes, making it less costly. The nugget machines are also a bit more compact and require less maintenance.
One main reason to choose one type of ice over another is its melting characteristics. Surface area is a main determinant of melt time. A cube tends to melt more slowly than flaked ice because it has less surface area and there is no water trapped inside as is the case with flake ice. The slower melting of an ice cube waters down a beverage less than flaked ice.
Flake ice, however, does have an important place in the back-of-house operation of a kitchen. Because it melts quickly, flaked ice transfers heat and chills product quickly. Flake ice is what you need when holding items like fresh seafood and chickens or for rapid chilling tasks. Nugget ice generally melts more slowly than flaked ice but more quickly than cubes. This melting characteristic makes the nuggets good for keeping soft drinks cold and while still permitting the ice to last for a reasonable period of time.
Once you choose the ice type, sizing ice makers is always a difficult thing to do because there are so many variables. Ice needs are rarely the same in any two operations. Requirements fluctuate depending on the type of operation, day of the week, and season in most operations. While it is difficult to predict, there are a few guidelines for ice usage at the end of this article. These usage guidelines include an allowance for waste and for ice melting in the bin. They also include other ice uses like the flaked ice applications noted above.
Establishing production needs
Once the number of pounds of daily ice production is determined, you have to match the production need with a machine's size. Some icemaker production claims can be misleading if you don't know what to look for. Be careful to note that many manufacturers' ice making claims are based on a 50°F water temperature and 70F° air temperature at the ice maker.
These temperatures are often unrealistic since in many areas incoming water temperature exceeds 50°F, especially in the summer when ice needs are greatest and the air temperature in the restaurant may be higher than 70°F. Exceeding these design temperatures can cause the machine's production capacity to decrease just when you need ice most!
The best way to avoid running out of ice on your hottest, peak use days is to buy enough ice capacity from the start. You want to buy ice and storage capacity for your peak, not just your average, demand.
When sizing an ice maker, be sure to take into account the air and water temperature to be sure enough ice can be produced. As a rule of thumb, a 10F° air temperature increase may reduce daily ice production by 10% when using an air cooled machine.
In addition a higher room temperature will melt ice in the bin more quickly, requiring more ice making capacity to replenish and fill the bin.
The amount of heat generated by air cooled machines is significant, especially if located in a small confined area or a space you may be trying to air-condition for the comfort of kitchen staff. The use of water-cooled ice makers, especially for larger machines, can reduce the amount of heat the ice maker itself adds to the kitchen.
The choice of an air cooled or water cooled machine is an important one. Ice makers use either air or water to cool their refrigeration compressor and condenser system. Each has advantages.
An air cooled condenser has a lower first cost and involves no added water costs. In most areas, water cooled machines must be designed to use a closed loop system, meaning no water can be dumped down a drain. A closed loop and cooling tower may or may not be feasible in your operation, however.
In addition to dispersing less heat than an air cooled machine, a water cooled system does have some significant advantages in terms of machine efficiency. A water cooled maker's electrical consumption is generally less when compared to that of a similarly sized air cooled machine. Water cooled units are also quieter in areas where noise is a factor. If water cooling is practical in your operation, use it.
A variation of the air cooled system is a remote condenser unit that offers some advantages of its own. The remote unit takes the biggest heat producing component, the condenser, out of the primary location and puts it in a remote one. The remote approach does not require water and removes most the heat from the service area. The condenser can be located up to about 50 feet away, sometimes on the roof.
Remote condenser ice makers are also quieter than typical machines because some of the machinery has been relocated. Tightly packed restaurants are a good application for remote equipment because of the reduced noise and heat. Whether you choose air or water cooled equipment, you will want to look for a machine with an Energy Star label for the most efficient equipment.
Here are two last items of importance to make sure you continue to provide quality ice. The first is to never underestimate the importance of a water filter for your ice maker. Water filters condition incoming water, reduce the machine's necessary cleaning frequency, allow top equipment performance, and improve the taste quality of the ice. Lime and mineral build up will be greatly reduced inside your maker if you use a filter. Use a good quality water filter and follow the directions for changing it when necessary.
Second, maintaining your ice maker properly is critical to productivity, food safety, and quality ice. Since ice is considered a food safety concern by many health departments, the cleaning and sanitation of ice machines is critical.
One feature you may want to consider is an automatic, internal self-cleaning system for the machine that includes built-in sanitizers and cleansers. Even if you have automatic cleaning options, still set up and perform a regular internal cleaning and maintenance schedule or contract with a service agency to do the work for you. The most important thing to remember about your ice maker is to choose a machine sized and designed to best meet your needs, and to then take care of it.
Dan Bendall is a principal of FoodStrategy, a Maryland-based consulting firm specializing in planning foodservice facilities. He is also a member of Foodservice Consultants Society International. Bendall can be reached at 301-233-5226.