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Energy Efficiency MeasuresCOMMERCIAL: REFRIGERATIONCommercial Refrigerators and FreezersHistorically, solid door, reach-in commercial refrigerators and freezers have been notoriously inefficient, but the Consortium for Energy Efficiency (CEE) has developed a specification for energy-efficient units that is being met by some manufacturers and have garnered ENERGY STAR certification. Also, EPA has begun ENERGY STAR labeling for efficient refrigeration products. Information is available on the Commercial Refrigerators and Freezers section of CEE’s web site at www.cee1.org/com/com-ref/com-ref-main.php3 and www.energystar.gov/index.cfm?c=commer_refrig.pr_commercial_refrigerators for ENERGY STAR. Walk-in CoolersThe floors of some walk-in coolers on farms and in grocery stores are simply concrete slabs that extend out of the cooled area. Accordingly, a good deal of cooling energy is lost to the ground and adjoining areas. Retrofitting these with floor insulation can be accomplished inexpensively using two-inch, closed cell Styrofoam™ tongue-in-groove insulation fastened to the slab using a low volatile organic compound (VOC) liquid adhesive dispensed from a caulk gun. The insulation should be covered by a good quality marine plywood attached to the insulation with the same adhesive and power staples, then finished with a sealer like a low-VOC urethane. Cooler door(s) should be designed or retrofitted to ensure good door operation, a tight seal when closed, and a gently sloping ramp to facilitate rolling goods into and out of the cooler. Vending MachinesMany commercial buildings operate vending machines provided by merchants who maintain the machines and keep them supplied with bottled drinks. However, most vending machines are very energy inefficient, yet the electricity bill is typically paid by the building operators, not the drink supplier. Toward lowering energy bills, a product called Vending Miser has appeared on the market which can save 1,000 to 1,500 kWh per year, roughly 30% of a vending machine’s annual energy consumption. Installed between the line plug of the vending machine and the wall outlet, the Vending Miser uses an occupancy sensor to assess the presence of people. After 15 minutes of inactivity, Vending Miser waits until the end of a compressor cycle, then turns off the vending machine until it detects someone or two hours have passed, whichever comes first. The effect is to turn off machines when they are not needed, thereby saving electricity while maintaining product temperature and being “open for business” when people come by to make a purchase. Refrigerators and FreezersReach-in refrigerators and freezers used in the food service industry account for 17% of all commercial refrigeration energy use, and are notoriously energy inefficient. Unlike residential refrigerators, there are no national standards to regulate their efficiency. ENERGY STAR began rating energy-efficient commercial refrigerator and freezers in 2001. A listing of ENERGY STAR commercial refrigerators and freezers can be found at www.energystar.gov/index.cfm?c=commer_refrig.pr_commercial_refrigerators. Ice MakersIce making machines are in wide use in hospitals, hotels, restaurants, retail outlets, schools, offices, and grocery stores. They account for over 10% of the energy used in commercial refrigeration. Ice makers are rated by the number of pounds of ice they can produce per 24 hours, and models ranging from 250 to 1400 pounds per day are readily available. The index of efficiency for icemakers is energy use per pound, and efficiencies range from 22 to 4 kWh per 100 pounds of ice produced. The least efficient (and least expensive) models use air as a medium for cooling; more efficient models use water. Some models use remote units which discharge heat from the compressor cycle outdoors, thereby lowering both the air conditioning load and compressor noise.
Some models use more water than do others for self-cleaning and removing scale, a factor that trades off with maintenance costs. Smart purchasing of ice makers involves matching the size of the machine to demand, taking into account energy and demand costs as well as water consumption and costs, estimating maintenance costs, and lifetime of the appliance. Energy-efficient units both use less electricity per amount of ice made and produce less heat that must be removed by the air conditioning system. The Los Angeles Department of Water and Power provides general information about ice makers at www.ladwp.com/energyadvisor/PA_31.html. The Consortium for Energy Efficiency (CEE) maintains a list of energy-efficient ice makers at www.cee1.org/com/com-ref/ice-main.php3. The Federal Energy Management Program (FEMP) also provides energy efficiency recommendations at www.cee1.org/com/com-ref/femp-rep.pdf. |
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Introduction | Recommendations by Sector | Energy Efficiency Measures Performance Contracting & Energy Service Companies | Program Profiles Case Studies | Glossary of Energy Terms | Home © 2003 Southwest Energy Efficiency Project |
