According to the Consortium for Energy Efficiency, a nonprofit organization that promotes energy-efficient products and services, the food service market consists of the most energy-intensive commercial buildings, consuming roughly 2.5 times more energy per square foot than other commercial buildings. With narrowing margins, foodservice operators are looking for energy-efficient solutions in response to rising energy costs.
Although various facilities contribute to the total energy bill, including HVAC, lighting, and sanitation; refrigeration equipment is quickly becoming a major factor. The total savings potential from a more efficient commercial kitchen can vary from 10 to 30 percent, depending on the technologies installed.
CRACKING DOWN ON REFRIGERATIONIn 2001, Energy Star enacted voluntary energy-consumption guidelines for commercial refrigerators and freezers. The California Energy Commission (CEC) then used those guidelines as the basis for a state law mandating new standards, while outlawing the sale of nonconforming products. New tiers are constantly being reviewed, each with decreasing allowances for energy consumption of refrigeration equipment.
In 2005, the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) took a proactive step toward the industry’s involvement in energy-consumption standards, recommending standards to Congress that were equal to the most stringent in California. The Energy Policy Act of 2005, which included AHRI recommendations, became law and will, in part, become effective in 2010. One goal of the Energy Policy Act of 2005 was to establish one national energy-efficiency standard for most products, as different energy standards in various states had led to confusion among consumers and businesses.
Various local and regional incentives will also gradually encourage adopting even more efficient refrigeration equipment.
Utility companies are joining in to encourage the transition to more energy-efficient refrigeration equipment by offering rebates for the purchase of Energy Star-rated commercial refrigerators, freezers, ice machines, and other types of refrigerated equipment. Rebates can total as much as $500 and are based on the tier efficiency rating of the equipment. Many manufacturers of refrigerated equipment provide links on their Websites to available rebates and incentives.
ENERGY-EFFICIENT COMPRESSORSManufacturers are responding to these standards with newly designed equipment. For example, the compressor can be responsible for up to 60 percent of a system’s total energy use. So, by choosing the most energy-efficient compressors, significant energy savings can be realized. Newer technologies, including system controllers, component diagnostics, and monitoring software can also help cut product energy use.
Hermetic compressors, in particular, are the workhorses of commercial kitchen refrigeration, according to advocates of that technology. These compressors are most often found in reach-ins, ice machines, and food prep tables. Compressor manufacturers have worked in recent years to make the hermetic compressor as energy efficient and reliable as possible.
Keeping energy efficiency in mind, hermetic compressors were developed for decreased size and cost. The body of the compressor is a formed metal shell that is hermetically sealed by welding. The motor is sealed inside and is usually spring mounted to cut vibration.
With hermetic compressors, suction gas travels through the motor area to cool the motor, and the compressor usually incorporates some type of protection against liquid flood back.
Bore, stroke, and valve plates are also optimized for certain temperature conditions, and an internal discharge muffler prevents excessive pulsation and vibration. Because of their energy-saving features, hermetic compressors are now widely used in many applications for small horsepower compressors.
Sidebar: ImprovementsOne example of hermetic technology for freezers and ice machines is Emerson Climate Technologies’ line of Copeland® brand hermetic refrigeration compressors. The line of 1/8- to 5-hp compressors offers new valve plates for improved energy efficiency, suction mufflers for decreased noise, optimized motors for improved starting, adhesive-coated gaskets for enhanced liquid handling, and redesigned bearing surfaces for better oil flow and wear reduction. The line is approved for the latest refrigerants in various refrigeration applications.
According to Emerson, these compressors are actually 2-10 dBA quieter, cutting out the need for a sound blanket or insulation. Five to 15 percent energy improvement will also cut down on coil costs and make it easier for customers to reach the next energy tier level.