High performance refrigeration cases
Published: March 3, 2016
Grocery stores use a significant amount of refrigerated equipment including display cases, walk-in coolers and walk-in freezers. This refrigeration equipment accounts for roughly 60 percent of grocery store electricity consumption. Due to this high electric demand, a typical grocery store’s average energy costs are higher than almost all other building types at $4.00 per square foot (Bendewald, 2013).
There are several technologies that can be applied to refrigerated display cases to improve their energy performance. These include:
- Light Emitting Diode (LED) lights,
- electronically commutated (EC) motors
- anti-sweat heater controls
- permanent doors on open dairy, deli and beverage cases
- night curtains for meat and produce open cases
Although the information contained in this guide pertains specifically to refrigerated display cases, many of these conservation measures can also be applied to walk-in cooler and freezers.
Energy savings from high performance refrigerated display cases vary depending on the temperature of the cases. Because low temperature (LT) cases have a larger cooling load, any measure that reduces the heat produced inside the cases, such as turning off anti-sweat heaters or reducing lighting and motor power, will save more energy than similar measures applied to medium temperature (MT) cases.
Additionally, replacing shaded pole (SP) motors with EC motors will result in greater energy savings than replacing permanent split capacitor (PSC) motors with EC motors.
Bendewald, Michael; Hendron, Robert; Krepchin, Ira, et al, 2013. Advanced Energy Retrofit Guide: Grocery Stores, U.S. Department of Energy. https://buildingdata.energy.gov/cbrd/resource/16
Coburn, Bruce; Faramarzi, Ramin; and Sarhadian, Rafik, 2000. A Study of Energy Efficient Solutions for Anti-Sweat Heaters, Southern California Edison.
Friedrich, Michele and Muellendore, Eric, 2011. Vertical Refrigerated Case, Medium Temperature: Open to Closed (Retrofit), PECI. http://rtf.nwcouncil.org/meetings/2011/0830/WP_PECIREF_CA%20DRAFT.pdf
Navigant Consulting, 2013. Guide for Retrofitting of Open Refrigerated Display Cases with Doors, U.S. Department of Energy. Website: http://www1.eere.energy.gov/buildings/commercial/pdfs/cbea_open_case_ret...
Royal, Richard, 2013. Refrigeration Commissioning Guide for Commercial and Industrial Systems, ASHRAE. Website: http://refcx.ashrae.org/