Spec Check: Induction Cooktops

For foodservice operators or cooking areas that don't have available gas, induction cooktops represent a viable option. Foodservice operators can use these in place of traditional gas and electric ranges as well as burners. This type of cooking can be fast and extremely energy efficient.

Induction-CooktopsInduction cooktops offer efficiency rates that approach 95 percent. With these units, boiling a gallon of water takes seconds, as opposed to 30 minutes or more with a typical gas burner. Low-end units tend to be less energy efficient and slower. For example, an induction burner with an efficiency rating between 60 percent and 70 percent will have longer cooking times at lower temperatures compared to one with an efficiency rating approaching 95 percent.

This technology runs electricity through an induction coil that produces a high-frequency magnetic field just above the cooktop. When staff place cookware made of ferrous material on this surface, the magnetic field causes the molecules in the cookware to vibrate, which heats the pan. Operators can choose from countertop or built-in induction cooktops. In addition, operators can opt to install newer hidden induction warming units beneath countertops.

When specifying this equipment, configuration
represents an important consideration. Cooktops come in single-, double-, four- and six-burner configurations, all either in drop-in or countertop styles. Relatively new to the market is direct contact food cooking, which includes such induction equipment as griddles and planchas.

Single and double hob models offer a front-to-back or side-by-side configuration. These come with the more familiar flattop cooking hotplates or in round bowl wok units. The range of cooktops available goes from 450 watt warming units to 10 kW stockpot units. The variety of functions includes low-power warming and wok ranges, in addition to single-, double- and four-coil units. Operators can also choose from griddle-top models and hidden warmers that heat through the countertop.

These units typically feature small footprints, which means space is generally not a primary consideration during specification. Single hob induction ranges typically measure 13 to 15 inches wide, 15 to 17 inches deep, and 3.5 to 5 inches tall. Double units measure roughly 27 to 30 inches deep.

The hobs generally will hold a 14-inch-wide vessel, but the cookware can be wider than the actual range. Typical stockpot capacities would be 24 to 40 quarts, but can be larger. Higher wattage ranges work with 60-quart stockpot applications. High-powered induction ranges that must accommodate stock pots and braising pans will tend to grow in size with power level.

In terms of placement, induction cooktops plug into almost any electrical outlet, allowing for flexible positioning. For those employing display cooking in catering and buffet applications, induction cooktops can emerge as a practical option. Buffet lines typically use two types of induction units. One offers an effective controlled heat source for keeping food items at proper temperatures, while the other acts as a cooking unit for action stations. Some induction ranges provide both heating and cooking modes.

Along with being useful for front-of-the-house applications, induction cooktops can be simple additions to kitchen cook lines, helping facilitate menu expansion. Because these units take up little space, operators can plug in induction ranges in back-of-the-house areas where additional prep work or finishing takes place.

Prior to purchasing an induction cooktop, operators should determine how they intend to use this equipment. Common applications include sauté stations, stock pot ranges, high-temp cooking, auxiliary heating stations for soup and sauce work, stir fry, warm salad condiments and pastry kitchens. These units also are suitable for single-plate demonstration cooking and plating.

Operators should use only induction-ready or magnetic pans with these cooktops, because those types of cookware provide the most even heat and efficient cooking.

Exterior construction choices range from plastic or aluminum housings with tempered glass tops to heavy-duty stainless steel housings with brand name ceramic-glass
composite tops.

Standard features vary, depending on the manufacturer, but can include empty pan protection and over-heating limiters. Some units include self-analysis by the induction range to adjust to varying cookware, voltages and electrical cycles. Manufacturers may offer either control knobs or touchpad operation. Control panels that rely on cooking levels to select temperatures generally offer between 20 and 100 settings.

In the United States, it is mandated that induction ranges are FCC listed and compliant, which helps ensure that the unit will not interfere with radio waves or electronics. Lower cost units may have higher wattage ratings, but it is likely that they do not meet the rated wattage over a wide range of cookware.

One common mistake operators make is not ensuring that the location has the correct power requirements needed to operate the type of induction ranges the property is specifying. It is imperative to provide adequate power for the cooking application. In terms of power, 1,800 watts is ideal for light sauté dishes and omelets; between 2,200 and 3,000 watts is appropriate for stir-fry, saucepots and higher volume cook stations; and between 3,000 and 3,500 watts or more can be used for high-volume applications, such as stockpots stations. For reference a 3.5kW induction burner, taking relative efficiencies into account, translates to a 31,000 Btu gas burner.

With induction cooking, the power and speed have a direct and linear relationship. For example, if it takes 90 seconds to boil a pint of water on an 1,800-watt unit, it will take 46 seconds on a 3,500-watt unit. Although the difference in a few seconds for sauté work might not matter, for larger volumes, such as large sauce pans, stock pots, etc., the time difference could impact speed of service.

Also, it is not uncommon for operators to fail to evaluate whether a hood is necessary. While induction units create no effluent, vapors from the cooking may still require some form of ventilation, depending on local jurisdiction and code.

Like computers, induction cooktops' electronic brains can misbehave or fail once they get too hot. Operators need to look at how the unit will react if overheating occurs. Some will suddenly reduce power unannounced in the middle of cooking at some point during overheating, which could be a problem, while other models wait longer before shutting down and showing an error code.

When first introduced, induction ranges had limited controls and were costly. Units now feature advanced power levels and temperature controls, are durable for true commercial environments and cost a fraction of the originals.


The Ambient Assessment

Induction is a high-tech product, and operations need to address this type of heating differently compared with traditional methods.

Operators should assess the environment in which they will use the unit. For example, if in the back of house, take into account grease and moisture in the air. Very hot, greasy, high humidity kitchens are not the proper environment for induction cooking. The electronics need to cool and will require ambient temperatures to be less than 105 degrees F.

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