The objective of this project is to install and analyze three different technologies to reduce the energy usage and intensity within a dishroom at a military installation used for cleaning and sanitizing of flatware, dishes, cooking vessels, and other foodservice related utensils. Included will be technologies to recover heat from waste water, to reduce waste water, to improve worker environmental conditions, and to reduce space conditioning loads. The specific Performance Objectives are 60% energy savings for heating water to the dishwasher, 30% energy savings for the ventilation system including fan power and energy to condition indoor air, and 75% savings for water for washing. The project will develop a Best Practices Guide and organize a workshop to assist energy managers, consultants, and commercial foodservice contractors at Department of Defense (DoD) locations in understanding the benefits of these dishroom technologies. The ventilation results also will be used as the basis for establishing dishroom ventilation standards that do not exist for any foodservice application.

Technology Description

This project will demonstrate three types of technologies for dishroom application at the U.S. Army Garrison - Presido of Monterey, California: waste water heat recovery, an advanced ventilation system, and a low water usage warewasher. An optimal savings potential can be achieved from the three technologies based on the interrelationship between them. The warewasher cleans dishware and other items producing steam and hot waste water at various rates depending on the load sizes. Newer gas-fired models require much less water than standard units and thus reduce water usage and energy usage to heat the water. The standard ventilation system vents the steam produced by the warewasher, but is sized to ventilate at the maximum load of the warewasher. A variable speed system saves energy and reduces loss of conditioned air by lowering the fan speed rate to match the venting requirements of the dishroom to maintain a comfortable work environment. A waste water recovery system reuses heat from the waste water to preheat inlet water to the warewasher that would otherwise be poured down the drain. By recovering waste heat and controlling the ventilation rate, less energy and water is used to clean the dishes and to maintain a comfortable work environment.

To demonstrate and quantify the energy and water savings of these technologies, the project team will use a test design employed by previous projects by Gas Technology Institute and Fischer Nickel, Inc. (FNi). The demonstration site will be fully instrumented with data acquisition equipment to measure the water and energy usage of the dishwasher, pre-rinse area, and ventilation system. Both the existing and new equipment will be monitored for six months to give an accurate comparison of the water and energy usage. The cost savings assessments will be done using existing life cost calculators for warewashers and ventilation systems developed by FNi and in accordance with the calculators provided by ESTCP.

Implementation Issues

Implementation of these technologies in the dishroom of a military dining at the U.S. Army Garrison - Presido of Monterey, California (DFAC) benefits DoD facilities by: (1) reducing energy usage, (2) reducing water usage, (3) improving the thermal comfort of the working environment, and (4) demonstrating system reliability. Based on the existing dishroom loading and layout at Presidio of Monterrey, a yearly savings of approximately 6,600 therms, 2,230 kWh, and 468,000 gallons of water can be realized. These savings equate to a yearly savings of about $16,000, and the purchase of the replacement dishwasher is estimated to be $48,000 less than the existing unit. The project results can be incorporated in standard dining facilities designs for military facilities as outlined in UFC 4-722-0 and into information and a workshop organized to help energy managers, consultants, and commercial foodservice contractors understand the benefits of the technologies and promote installation at other DFACs. (Anticipated Project Completion - 2017)