Walk-in coolers and freezers (walk-ins) are large, insulated refrigerated spaces with access door(s) large enough for people to enter. Walk-ins are used to temporarily store refrigerated or frozen food or other perishable items. The equipment is composed of an envelope (panels and doors) and a refrigeration system.
In 2004, California set the first standards for walk-ins, reducing average walk-in energy use by over 40% through prescriptive requirements for insulation levels, motors, and use of automatic door-closers. Connecticut, DC, Maryland, Oregon, and Rhode Island later adopted the California standards. In 2007, ACEEE reached an agreement with walk-in cooler and freezer manufacturers on national standards for walk-ins that built upon the California standards but added some provisions and modified others. This agreement was incorporated into the Energy Independence and Security Act (EISA) of 2007 and includes prescriptive requirements for the thermal enclosure, motors, and lights. The EISA standards went into effect January 1, 2009.
In May 2014, DOE issued new standards for walk-ins which require separate minimum efficiency levels for panels, doors, and refrigeration systems. In addition, DOE adopted an innovative approach that allows manufacturers to certify either the refrigeration system or its components, which provides flexibility for both manufacturers and customers. The rule will reduce the cost to operate a refrigeration system for a walk-in cooler or freezer by 10-38%, depending largely on the size of the walk-in.
The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) and others filed a lawsuit against the 2014 rule which resulted in a settlement agreement. Among other things, the settlement agreement remanded the standards for certain types of walk-in refrigeration systems to DOE for rulemaking using a negotiated rulemaking process. Of the 19 standards established in the 2014 final rule, 6 were remanded. In 2015, a working group comprised of manufacturers, efficiency advocates, contractors, and DOE successfully negotiated new standards for the remanded equipment types.
The standards for doors take effect in 2017. The standards for the non-remanded refrigeration system equipment classes take effect in 2017, but DOE will use their enforcement discretion to not enforce these standards until 2020. The effective date for remanded equipment types will be issued when DOE publishes a final rule.
DOE estimates net present value savings of up to $9.9 billion on purchases through 2047 and CO2 emissions reductions of 159 million metric tons over the same period.
Walk-in coolers and freezers are generally assembled on-site from pre-fabricated wall, ceiling, and floor panels; doors; a refrigerator system; and electrical components. Technology options for reducing walk-in energy consumption include improved insulation, floating head pressure control, evaporator fan control, and high-efficiency compressors, fan blades, and fan motors.