Grocery stores are among the most energy intensive types of commercial buildings. This is primarily due to the high energy use of refrigeration systems that may make up more than 50% of the electricity use in a typical grocery store. Monthly electricity costs for grocery stores in California can range from $10,000 to $15,000 per month. In addition, grocery stores' profit margin on sales is very low -typically two percent. Cost savings from improvements in refrigeration efficiency go directly to the bottom line and have a significant impact on store profitability. The paper presents an overview of several cost effective opportunities for energy efficiency retrofits in supermarket refrigeration controls. The author discusses refrigeration equipment and controls upgrades drawing from his recent experience with retrofit and new construction projects in over 50 commercial grocery facilities in Oregon, Washington, Utah, and California. The paper begins with a brief overview of typical system types and control strategies that are found in existing facilities. Next, the paper discusses potentially cost-effective retrofit options for controls. These options include improved condenser fan controls, anti-sweat heater controls, floating suction temperature controls, floating head pressure controls, and case-lighting controls. For each technology the paper discusses energy savings as well as potential installation pitfalls to avoid. A discussion of commissioning as applied to retrofit refrigeration projects 'will demonstrate the particular value of commissioning for these retrofits, and demonstrate the level of reporting capable with the newest controls. The paper concludes with a discussion of the pros and cons of the current options for modeling energy efficiency measures in supermarket refrigeration systems. There are new methods that promise to improve the level of analysis for these types of projects. The author discusses these recent improvements and also the areas where improvements are still needed.
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