Estimating the Annual Water and Energy Savings in Texas A & M University Cafeterias using Low Flow Pre-Rinse Spray Valves

Abstract

Improving the efficiency of a Pre- Rinse Spray Valve (PRSV) is one of the most cost effective water conservation methods in the Food Services Industry. A significant contributor to this cost efficiency is the reduction in the energy costs required to provide the mandatory hot water. This research paper estimates the potential quantity and dollar value of the water and energy that can be saved annually in Texas A&M University's dining services with the installation of low flow pre-rinse spray valves. The data collection was obtained from four of Texas A&M University's Dining Services facilities. The annual savings were estimated by contrasting the water consumption of the existing T & S Brass B 0107-M PRSVs with the latest and most advanced available low flow T and S Brass B 0107-C PRSV. The annual water consumption of the existing and new PRSVs were predicted by measuring an individual average flow rate for each and observing the number of hours per day the PRSV would be used. The observed and measured values were extrapolated to amount rates to determine cost savings. The dollar value was ascertained using the utility cost data recorded over a semester by the Facilities Coordinator of the Department of Dining Services. The findings of this study show that the water savings from a single PRSV could lead to an estimated annual saving ranging between 46% and 78% of the current operation cost. The T & S Brass B 0107-C PRSV is currently priced between $52- $60 per valve resulting in a payback period ranging between 1.5-6 months per valve. If every valve on campus was replaced, the University could reap a savings in the range of $ 5,400- $22,590 over the 5 year useful life of the valve, having initially invested less than $550.