Undercounter, door type, conveyor, flight type, pot & pan washers.
Note that the heading is “Dishmachines”, not “Dishwashers”. A dish machine’s primary use is to sanitize the ware, as well as clean it. The type of machine that you will require depends on the type of soil on the ware, the volume of ware and the length of time between soiling the dishes and when it is required back in service. Undercounter machines are too small for school foodservice and flight type machines are only for the very largest applications, which are very rarely in schools. Normally a door type machine is used in smaller schools, up to approximately 300 meals. A conveyor is usually used for schools over 300 meals.
A door type machine holds one rack of ware and washes in about 1.5 minutes, including wash and rinse. A conveyor machine may consist of several parts. All conveyors must have a wash area and a final rinse, which sanitizes at 180 degrees. In addition, a pre-rinse unit, or “scrapper” may be added to the entry area of the machine to pre-rinse the ware and remove baked-on soil. There are typically two size pre-wash sections, either 22″ wide or 36″ wide. It is usually advisable to consult with your foodservice consultant or a manufacturer’s representative to determine your needs and to assist you in writing your specifications.
You must know the volume to be cleaned, the time between cleaning and reuse, the amount of soil that will be on the ware, how many employees will be in the dishroom, incoming water temperature (critical). IT IS IMPERATIVE THAT A DRAWING OF THE DISH ROOM ACCOMPANY ANY SPEC REQUEST. A DISH ROOM MUST BE DESIGNED AROUND THE AVAILABLE SPACE AND THE CONFIGURATION OF THE ROOM. There are machines built that will work perfectly in the corner, using power loaders or power un-loaders.
The proper selection of type and style of dishmachine is difficult. Often a machine that is too large or too small is selected. This is one area that the foodservice director should seek help from a warewashing professional. Also, be concerned with the incoming water temperature. Most BOOSTER HEATERS are designed only to raise the incoming water temperature by 40 degrees. So, if the incoming temp is 140 degrees the booster should increase it to the 180 degrees required by the health department for sanitizing. A “low temp” or chemical machine uses a chlorine additive in the final rinse to act as the sanitizer in lieu of 180 degree rinse water. However, “low temp” is still 140 degrees. Be ABSOLUTELY SURE of the incoming water temperature so that a proper sized booster may be specified. Most schools use high temperature sanitizing.