There’s more to a dish room than meets the eye. Learn what makes up a good design before you start selecting equipment.

If you own a restaurant, odds are you’ll wash a fair amount of dishes. But there’s a lot more to a dish room than the dishmachine itself. Unfortunately, restaurant kitchen designs too often relegate dish rooms to whatever space is left over after food storage, prep and cooking areas are laid out. But dish room layout—and the equipment you put in it—is just as important from both food safety and productivity perspectives as the rest of your kitchen.

Dish Room Setup and Flow

Workflow in the dish room should be designed to prevent cross-contamination between dirty dishes and cookware and clean ware. Designs should include plenty of space to handle the inflow of dirty dishes, pots and pans during a rush while both dishwashers and dishmachines catch up, as well as an area for racks of clean items to dry and accumulate before they’re put away.

A typical dish room layout has a landing area for dirty dishes long enough for two or three bus tubs, with angled shelves above for glass racks. Dish room workers clear and rinse plates at a scrapping sink with a pre-rinse spray nozzle and scrap screen. These sinks typically have food waste disposers. A feed area in front of the dish machine should be large enough to hold a dish or glass rack so dishwashers can easily load scrapped tableware before putting the rack in the dish machine.

Depending on the size of your operation and local codes, you may have a separate landing area for pots and pans, either next to a three-compartment sink or a pot washer. If pots and pans are run through the same dish machine you use for tableware, however, you may want a bigger landing area.

At the clean end of your dish machine, you should have an equally large landing area or clean table so dishes coming out of the dish machine have a chance to air dry until dishwashers can unload the racks and put clean dishes on transport carts or wire shelves to be put away. Often, dish rooms have only one entrance/exit, so it’s important that the layout sends dishes in a circular pattern from dirty to clean to help prevent cross-contamination. Keep garbage containers at the “dirty” end of the flow.

Local Codes Come First

Dishwashers are required in most locales to have a Type II ventilation hood; because your dish room must have a way to vent air to the outside, your dish machine may have to be placed in a certain location—unless you purchase a ventless machine (see below).

Three-compartment sinks are required in addition to dishmachines in some locales; Wisconsin requires a four-compartment sink. Food disposers are allowed in much of the country but are banned in others, particularly areas not on municipal sewer lines. While you may have an overall design that works well in your operation, code will dictate what you can and can’t do.

What type of dishwasher you pick largely depends on what type of wares you’re washing in your restaurant and how many pieces. To determine the size you need, figure the number of pieces of tableware you use per patron. Multiply that by the number of customers you serve per hour (at peak periods). Then divide that number by 20 (the number of dishes that typically fit in a rack). The result is the number of racks per hour your dishmachine should be capable of washing.

Commercial Dishmachine Types


Undercounter Commercial Dishwashers

Undercounter dish machines can wash about 500 dishes an hour, about the same time it takes your dishwasher at home to run a single cycle. Undercounter commercial dishwashers take up less space than three-compartment sinks, which often make them ideal where some glass or warewashing is necessary, but space is at a premium, such as in coffee shops or sandwich shops. They can handle 50 or fewer meals per hour.

Door Type Dishwashers

Stationary, single-tank, door-type dish machines fill a niche between smaller undercounter dishwashers and rack-conveyor machines. Strong and powerful enough to handle pots and pans, these workhorses can wash up to 60 racks an hour—or as many as 1,200 dishes. Operations that find door-type dishmachines most useful are restaurants with 100 to 150 seats or high-volume quick-service (fast food) units that use disposables and only need to wash pots, pans and parts.

Rack Conveyor Dishwashers

Basic rack-conveyor dishwashers are single-tank machines and usually start at about 44 inches in length. Water is heated in the tank, detergent is added and the water is pumped through spray nozzles as the conveyor carries the rack of dishes through the machine. These dishmachines are great for high-volume full-service restaurants and can be expanded to fit the needs of larger operations, typically full-service restaurants of 150 seats and up.

Flight-Type Dishmachines

The largest type of dishmachine, used most often in institutions such as hospitals, colleges and universities, and corporate foodservice, are continuous conveyor flight-type washers. These are almost always made to spec.


Though usually located behind the bar or in a bus station, these specialty dishwashers sometimes are found in dish rooms, too. They typically have slightly different cycles and spray arms to handle more delicate glassware. You can choose from undercounter batch dish machines that wash a rack at a time or continuous pass-through or circular conveyor washers that employees load by the piece on a belt.

Pot Scrubbers

Most manufacturers also give you the option of a model with a higher opening. Most standard models have an opening about 19 in. high. Models with taller openings can accommodate sheet pans more easily (instead of running one through at a time). Some are designed with longer wash cycles specifically for restaurant pots and pans.

View all commercial dishwashing units here.

A Word About Ventless Dishwashers

No space for a Type II hood? Ventless dishwashers eliminate the need for a hood by including a condensing coil in the machine. The coil condenses the humidity inside the dish machine and transfers the heat from that air and uses it to help heat incoming cold water for the wash tank. You get the dual benefit of saving the cost of a hood as well as some of the energy that would have been required to heat wash water in the tank. An added bonus: You’ll save on HVAC costs by not having to supply makeup air to the dish room hood.

A potential drawback to consider: Cycle times of ventless machines are extended, typically by about 30 seconds, for condensation and heat transfer. That lowers the throughput of most ventless models to around 27 to 38 racks per hour.

Booster Heaters

The tank in a high-temp dishwasher has a heater that will bring your 140° F hot water up to wash temp, but you’ll need a booster heater to heat the final rinse water. Some machines have boosters built-in, but Central Restaurant Products also has a range of booster heaters to fit your needs.

Dish Tables

Provide at least 48 inches of worktable—enough to hold two racks of dishes—on either side of the dish machine. This will give your employees adequate feed and landing space for loading and unloading dishes. Most restaurant dish machines these days can be field retrofitted for straight-line or corner set-up, and CRP can provide dish tables to fit almost any room configuration.

Scrap Area/Water Troughs/Disposers

Typically, you’ll want a sink with a pre-rinse sprayer and filter basket built into the dish table on the feed end of the dish machine where you can scrap dishes. Most foodservice operations will add a food disposer to that sink, but check your local code to see if it’s okay.


Again, local code, along with space considerations, will dictate what sinks are required in a restaurant dish room. A few types you’ll likely end up with include:

Dish Racks

Be sure to have enough extra racks on hand so dish room employees always have empties to load while other racks of clean wares are either drying or being used to store extra glasses, dishes, etc.

Additional Dishwashing Accessories and Supplies

Don’t forget all the extra supplies your restaurant dish room staff needs to make quick—and safe—work of their jobs.

Pulling It All Together

Here are two basic restaurant scenarios, with dish room scrapping area layout and equipment recommendations. In each case, consider them the bare essentials.

Quick-Service Restaurant

While quick-service restaurants (also known as fast-food restaurants) typically serve food in disposables, most have pots, pans, food containers and utensils that must be washed and sanitized. Dish room equipment needs include:

  • a 5-foot stainless soiled ware table
  • 20 x 20 sink with scrapping screen, pre-rinse spray arm, and disposer, if allowed
  • door-type dish machine or pot scrubber
  • three-compartment sink, if required.

Fast-Casual and Full-Service Restaurants

These types of restaurants tend to serve food (often made-to-order) in permanent ware and have pots, pans, food containers, etc., to be washed and sanitized. Dish room equipment needs include:

  • a 6-foot soiled dish/scrapping area with trough leading to disposer—or similar-size soiled scrapping area with recirculating sink with disposer, if allowed (if no disposer is allowed, undercounter food pulper/extractor)
  • angled overhead glass racking; flatware/utensil soaking bin
  • pre-rinse spray arm at 20 x 20 sink or three-compartment sink or pot scrubber for pots and pans
  • 44-in. or larger rack conveyor dishmachine.

Hot or Cold Dishwashing

High-temp warewashers wash at about 155° F and sanitize using water that’s at least 180°F. Low-temp machines use wash water that’s around 120° F to 140° F and a chemical sanitizing solution in the final rinse. Since they don’t require a lot of power to heat water, most run on 115v electric service, making them suitable in a variety of applications where lighter soils are the rule, such as sandwich shops, for example, or where electrical service isn’t adequate to power a high-temp machine.



  • Better results. Removes lipstick/oils/grease better than low-temp
  • Fresh water rinse leaves no chemical sanitizer residue
  • Less caustic to machine and serviceware
  • Lower chemical costs


  • Higher purchase price due to built-in booster heater
  • Requires higher electrical service
  • Leaves glassware and dishes hot (which also dries them faster, a “pro”)



  • Uses less power; requires standard electrical service
  • Lower purchase price; can also lease from chemical companies for little or no cost when you purchase their products


  • Higher chemical cost
  • May leave a chemical odor and residue on glasses and dishes.
  • Chemicals are hard on the washer and wares

Additional Reading

You might also enjoy our buying guides on commercial dishwashers and sinks.

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