May 2024 EnergyWise Tip: Doing the Dishes

 May 2024 EnergyWiseSM Tip: Doing the Dishes

By: Energy Efficiency Program Manager Cory Fuehrer

Of the more than one million food service businesses in the United States, the National Restaurant Association estimates more than 260,000 are full-service restaurants. Considering the average restaurant serves about 100 customers per day, that means a lot of dirty dishes!

Not surprisingly, pre-rinsing, washing and sanitizing consumes the largest amount of hot water in commercial kitchens. Unlike most residential kitchens, commercial kitchens tend to use pre-rinse spray valves (PRSVs) to remove food waste from dishes prior to dishwashing. Their concentrated jet of hot water reduces the scraping and scouring necessary before sending dishes to the dishwasher. Food service establishments run nearly 53 billion gallons of hot water through PRSVs each year. Replacing an old, inefficient pre-rinse spray valve with a high-efficiency, DOE-compliant model can save a typical commercial kitchen more than 7,000 gallons of water per year.

Commercial dishwasher design can vary greatly depending on how many employees, visitors, and/or customers are served. Smaller facilities serving fewer than 60 people per day often hand-wash dishes or use undercounter dishwashers similar to residential units. As the number of customers served increases, stationary door- or hood-type commercial dishwashers are selected by establishments serving 100 people or more per day. These may be manually front-loaded with racks or have conveyor belts that automatically run dishes through.

The most efficient commercial dishwashers reuse water from one wash load to the next, using one or more holding tanks. This not only reduces water use, but also reduces the amount of energy required to heat additional water.

Commercial dishwashers that have earned the ENERGY STAR® rating are on average 40% percent more energy and water-efficient than standard models. ENERGY STAR®-certified dishwashers have features such as advanced controls and diagnostics, improved nozzles and rinse arm design to save $1,300 annually and $16,000 over the product lifetime when compared to standard dishwashers.

Restaurants can further improve dishwashing efficiency with the following inexpensive good practices:

• Run fully loaded dish racks through the dish machine. Cutting the number of wash cycles can save hundreds of dollars annually in energy, water, and chemical charges.
• Pay attention to the dishwasher’s pressure gauge—if it’s showing pressure above 25 psi, it’s likely using much more water than necessary. Most commercial dishwashers require only around 20 psi.
• Conveyor-style dishwashers should be used in auto mode, which saves electricity by running the conveyor motor only when needed.
• Install a booster heater for high-temperature dishwashers rather than turning the facility’s water heater up.
• Use a commercial ventilation hood over high-temperature washers, and switch it off during idle periods or when washing is complete.

• Replace any torn wash curtains or worn spray nozzles.
• Repair leaks and perform regular maintenance.

In partnership with Nebraska Public Power District, your local utility wants to help food service establishments make the most from the energy needed to clean and sanitize kitchenware and dishes. For additional ways on how you can make your home or business EnergyWiseSM, contact your local utility or visit www.energywisenebraska.com for more information.