Case Studies in Restaurant Water Heating

Panel: Strategies for Appliances, Lighting, Electronics, and Miscellaneous End–Uses

Authors:
Donald Fisher, Fisher-Nickel, Inc.
William Pietrucha, Pacific Gas and Electric Company

Abstract

This paper presents an overview of hot water use and the associated energy loads in the commercial food service and restaurant sector, with a focus on the potential to reduce these loads by improving hot water use and increasing water heater system efficiency. Recent results from field studies are presented for a full-service and quick-service restaurant. The performance of gas-fired standard efficiency tank-type heaters, high efficiency (condensing) tank-type heaters, and instantaneous (or "tankless") heaters are compared. The parasitic impact of the re-circulation loop on hot water system efficiency is illustrated for the full-service operation. Field testing results indicate restaurants can save 8.6 to 19.5% by installing high efficiency water heaters- either tank-type or tankless. The study also suggests that operators of full-service facilities can save up to 10% by installing pipe insulation, flue damper controls, and hot water circulation pump controls. Research on hot water use in commercial food service facilities should be expanded and water heater testing should continue to validate this energy saving potential. In support of the "gas savings" goals of California utilities and the California Energy Commission, an incentive should be considered to encourage retro-commissioning and installation of highefficiency water heaters for commercial applications.