BMP #11 - Commercial Kitchen Equipment

Background

Commercial kitchen equipment used by the food service industry represents a large set of water users in the non-residential sector. Commercial kitchen equipment water efficiency is especially important because the high volume applications typically require the use of mostly hot water. Therefore, making sure commercial kitchen equipment uses water efficiently affords both significant water and energy savings. Types of 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).

For more information on this and other FEMP Water Efficiency Best Management Practices, please see the resources section.

Operation and Maintenance Options

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. Encourage 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's water temperatures and flow rates to ensure that they are within the manufacturer's recommendations. For maximum water savings, water flow rate should be near the minimum allowed by the manufacturer.
Test system pressure to make sure it is between 20 and 80 psi. If the pressure is too low, then high-efficiency devices won't work properly, if it is too high they will consume more than their rated amount of water.
For dishwashers, observe final rinse pressure to make sure it is at the manufacturer's recommended setting, typically 20 ± 5 psi. If the pressure is too low, then the dishes may not be rinsed and sanitized properly, if it is too high they will consume more than their rated amount of water.
Ensure all equipment is installed and operated in accordance with the manufacturer's 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 be sure to 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 as opposed to 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.
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

Install dishwashers with rack sensors to allow water flow only when dishes are present.
Check to see 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; otherwise replace the ice-making head with an air-cooled unit.
Flow restrictors can be installed in existing pre-rinse spray valves to reduce the flow rate to 1.6 gpm or less. Flow restrictors, however, may not provide adequate performance in most situations and purchasing new more efficient and inexpensive pre-rinse spray valves may provide a better alternative for saving water.

Replacement Options

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 with the ENERGY STAR® label. If possible, install low-temperature machines that rely on chemical sanitizing over high water temperature. If purchasing a low-temperature chemical sanitizing machine, carefully consider the cost of chemicals and verify water use with the distributor or manufacturer to ensure that the machine uses less water than an equivalent high-temperature machine.
Replace water cooled commercial ice makers with high-efficiency air cooled commercial ice makers with the ENERGY STAR label.
For low to medium volume steam cooking needs, purchase high-efficiency steam cookers with the ENERGY STAR label or purchase boilerless (connectionless) commercial steam cookers. Specifically look for steamers with improved insulation, standby mode, and closed-system design, to ensure that 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 must have a maximum flow rate of 1.6 gpm. In 2007, the Federal Energy Management Program (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), however, 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.

Commercial Kitchen Equipment Resources

ENERGY STAR®.

Food Service Technology Center.

U.S. Department of Energy. FEMP Purchasing Specifications for Energy Efficient Products.

U.S. Department of Energy. FEMP Focus - Clean Up with Water Savings, Fall 2004.