Specific warewasher types are designated for different types of foodservice operations and volumes.

Undercounter machines are most often used in bars, kiosks and low-volume operations, while door-style machines are typically specified for small- and medium-sized restaurants or smaller school foodservice operations. Flight-type or rackless warewashers are best suited for large cafeterias, banquet halls and catering operations while conveyor units are for restaurants with high volumes that require increased throughput.

If operators will wash larger pans, consider a taller unit. Bigger operations may require a conveyor machine. Rack or circular conveyor units are geared toward full-service restaurants and higher-volume applications, such as universities and healthcare foodservice. These units pull racks through the wash tank and a rinse area and then out (as opposed to dishes staying in the zones and washing and rinsing happening in same place). It speeds up the process and potentially increases dish washing volume.

High-temp door machines have a higher chamber height and can wash anything up to 27 inches tall. Lower-volume restaurants tend to choose single-door machines, which have a 19-inch opening, rather than the taller version.

Specialty warewashers may be necessary, depending on the application. For example, pot, pan, and utensil machines offer between a 6- to 60-pan capacity.

With booster heaters and water use, warewashers are the single biggest energy consuming pieces of equipment in commercial kitchens. Today, however, most models are energy and water efficient, using less than a gallon of water per rack for each wash cycle. Those with older machines should consider the water and energy use, as they may save money over the long run with a newer unit.

Since different wares have well-defined washing requirements, operators must determine what exactly they will wash to specify the correct unit. This also will determine if racks or tables are appropriate for the dishroom. If the operation will wash a variety of items in the unit, look at the model’s flexibility. When the ability to wash varied loads that are intermixed is important, consider a system that offers random loading capabilities.

In addition, confirm the durability of items the unit will wash. If a warewasher does not provide a gentle cycle, it will add significant premature wear to certain items being washed or even shorten the service life of these items.

Verify capacity or throughput. Compare the ratio of usable cubic inches of wash area versus the unit’s overall footprint. Tank sizes are measured in 6-inch increments. Throughput speed will determine how fast the system can wash the items required. The bigger the warewasher and the faster it runs, the more efficient it will be.

Like many pieces of equipment, operators should consider the costs associated with the many consumables related to warewashing, such as detergent, rinsing agents and other chemicals. Be aware that water softness or hardness contributes to lime and scale buildup, which can result in the need for more detergent during the wash cycle.

Consider energy consumption and water usage. Energy Star-rated warewashers may save money over time.

Examine where the wash jets are located to get a better picture of the wash action consistency.

Ergonomics are another factor when specifying warewashers. Consider how employees will load and unload the unit.

Consider the location of the warewasher. If there are not space constraints, it may be best to purchase a larger unit for increased efficiency, flexibility, capacity at peak periods and future expansion of the operation. Consider the noise levels, which can be an issue with some warewasher types. If the dishwashing area is located by the dining room, a quieter unit may be best.