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Best Management Practice #11: Commercial Kitchen Equipment

Commercial kitchen equipment represents a large set of water users in the non-residential sector. Water efficiency for commercial kitchen equipment is especially important because high volume applications typically use mostly hot water. Ensuring commercial kitchen equipment uses water efficiently affords both significant water and energy savings.

Water-using commercial kitchen equipment include pre-rinse spray valves, wash tanks and sinks, commercial dishwashers, food steamers, steam kettles, commercial ice makers, and combination ovens (combination oven/steamer). Find more information about commerical kitchen equipment in FEMP's food service covered product category. Additional equipment information is available from ENERGY STAR and the Food Service Technology Center.

Operation and Maintenance

To maintain water efficiency in operations and maintenance, Federal agencies should:

  • Educate staff about the benefits of water efficiency and the importance of hand scraping before loading a dishwasher.
  • Establish a user-friendly method to report leaks and fix them immediately. Require cleaning or custodial crews to report problems.
  • Only run dishwashers if they are full. Fill each rack to maximum capacity.
  • Immediately replace any damaged dishwasher racks.
  • Check equipment water temperatures and flow rates to ensure each is within manufacturer recommendations. For maximum water savings, water flow rate should be near the minimum recommended by the manufacturer.
  • Test system pressure to make sure it is between 20 and 80 psi. High-efficiency devices won't work properly if pressure is too low. If pressure is too high, they will consume more than their rated amount of water.
  • For dishwashers, observe final rinse pressure to ensure it is within manufacture recommendations, typically 20 ± 5 psi. If the pressure is too low, the dishes may not be rinsed and sanitized properly. If it is too high, they will require more than their rated amount of water.
  • Ensure all equipment is installed and operated in accordance with manufacturer instructions.
  • Use the combi-mode of combination ovens sparingly and appropriately as this mode consumes water and significantly increases energy usage. Combi-mode should be minimized and convection mode maximized. By moderating use at the beginning of the cook cycle, the benefit of the combi-mode can be achieved without using the mode for the entire cooking event. When adjusting the use of the combi-mode, consider the impact on cook times and product yield.
  • For steam cooking, use batch production as opposed to staged loading of food pans (i.e., do not continuously open the door to load and unload food pans). This uses a lot of energy and wastes water. If possible, fill the steamer to capacity instead of cooking one pan in a five pan steamer.
  • Some pre-rinse spray valves may be easily taken apart to perform routine cleaning or to clean when performance is noticeably impacted. However, because pre-rinse spray valves are relatively inexpensive, it may be more viable to replace plugged or poorly performing valves with new efficient models. If cleaning or maintenance is necessary, avoid drilling out holes to remove scale and buildup. If replacing, choose a FEMP designated pre-rinse spray valve, which designates pre-rinse spray valves that have flow rates of 1.25 gpm or less and meet ASTM F2323-03, Standard Test Method for Performance of Pre-Rinse Spray Valves.
  • Garbage disposals can waste significant amounts of water. Eliminate or minimize the use of garbage disposals by using strainers or traps that employ a mesh screen to collect food waste.

Retrofit Options

The following retrofit options help Federal agencies maintain water efficiency across facilities:

  • Install dishwashers with rack sensors to allow water flow only when dishes are present.
  • Check if ice machines operate with single-pass cooling. To maximize water savings, eliminate single-pass cooling by modifying equipment (if possible) to operate on a closed loop that recirculates the water instead of discharging it. In 2011, FEMP released a purchasing specification for water-cooled ice machines, which identifies water-cooled ice machines that are connected to a cooling tower that operates year round and meet the performance requirements as listed in the performance requirements. Otherwise, replace the water-cooled ice machine with an ENERGY STAR®-qualified air-cooled unit.
  • Existing pre-rinse spray valves with new more efficient and inexpensive FEMP designated pre-rinse spray valves to reduce the flow rate to 1.25 gallons per minute (gpm) or less.

Replacement Options

The following replacement options help Federal agencies maintain water efficiency across facilities:

  • For commercial dishwashers, check volume of service and size the dishwasher accordingly. Be sure to consider the energy tradeoff associated with increased tank heat that may be required for larger machines.
  • Purchase high-efficiency commercial dishwashers that are ENERGY STAR®-qualified.
  • Replace water cooled commercial ice makers with high-efficiency air cooled commercial ice makers with the ENERGY STAR-qualified label.
  • For low to medium volume steam cooking needs, purchase high-efficiency steam cookers with the ENERGY STAR-qualified label or purchase boilerless (connectionless) commercial steam cookers. Specifically look for steamers with improved insulation, standby mode, and closed-system design to ensure steamers are used most efficiently. Select a steamer based on projected use (i.e., balance production demand with steamer production capacity).
  • Purchase high-efficiency pre-rinse spray valves. The Energy Policy Act of 2005 requires that pre-rinse spray valves manufactured after January 2006 have a maximum flow rate of 1.6 gpm. In 2007, FEMP released a purchasing specification for pre-rinse spray valves, which requires Federal agencies to purchase pre-rinse spray valves that have flow rates of 1.25 gpm or less and that meet ASTM F2323-03, Standard Test Method for Performance of Pre-Rinse Spray Valves. For ease of maintenance and to increase operational life, purchase pre-rinse spray valves that can be easily taken apart and cleaned.
  • Consider steaming needs when purchasing steam kettles. Direct steam kettles may be appropriate for bulk cooking (more than 50 servings at a time), but may require more maintenance as they are supplied with steam from an external boiler and may need to be "blown down" daily to eliminate condensate buildup in the steam supply line. For smaller steaming needs, purchase self-contained steam kettles. Self-contained kettles may require regular monitoring of water levels and maintenance of control components.

 Resources

The following resources provide guidance on water best management practices.

Case Study

The Exchange, formerly the Army and Air Force Exchange Service (AAFES), took a leadership role in kitchen appliance upgrades to improve water efficiency by integrating water efficiency concepts into the organization's overall sustainability plan and objectives.