Showcasing Energy Efficiency Solutions in a Cold Storage Facility

Ramin Faramarzi, Bruce A. Coburn, and Rafik Sarhadian, Southern California Edison

Keywords

Abstract

Refrigerated warehouses have one of the highest electric energy usage intensities in the commercial building sector (Leue and Eilert 2000). Their electric usage, often ranges from 40 to 60 kilowatt-hours per square foot per year, with refrigeration accounting for more than 70 percent of overall electric usage. Although refrigeration equipment performance in cold storage facilities is not governed by any efficiency standards, these facilities can benefit significantly from commercially available energy efficiency solutions, which can reduce energy consumption and improve food safety by providing desirable temperatures.

This paper presents the findings of an energy efficiency showcase of a 24,600 squarefoot cold storage facility in Ontario, Calif. A short-term end-use monitoring plan was deployed to capture the impact of the following energy efficiency solutions:

Enclose an open loading dock area and add energy efficient cooling and dehumidification to reduce cooling load.
Design and implement a new state-of-the-art refrigeration system, with advanced controls; sub-cooling; floating head pressure; high efficiency evaporators, condensers, and motors; and variable speed drives.

At a mild ambient temperature of 65oF, the new system reduced daily refrigeration energy use by approximately five percent, and reduced the facility’s peak electric demand by five percent. (The site is, however, exposed to temperatures higher than 65oF during summer.) Additionally, the north and west freezers’ storage temperatures dropped by 2.6oF and 5.6oF, respectively. These improvements were achieved despite a 17 percent increase in refrigerated floor space.