Quick-service restaurants could cut their energy bills by between 41 and 52% if they adopted measures suggested by the DoE's Pacific Northwest National Laboratory. Moreover, PNNL figures the payback period for installing the energy efficient gear would be a little over two years.
So says a recent PNNL report called PNNL-19809, Technical Support Document: 50% Energy Savings for Quick-Service Restaurants. PNNL researchers modeled a typical quick-service restaurant and figured the savings based on typical usage rates for equipment and restaurant square footage.
Some of the recommendations for savings are common-sense measures for any commercial building: use energy efficient lighting, make use of daylight to reduce lighting bills, use occupancy sensors and photocells on exterior lights, and make sure the building insulation and windows are first rate. But many of the recommendations apply to kitchen gear. This is important because depending on the appliance, some 20% or even more of the annual energy use can happen when the appliance is idling, as when not cooking or frying anything.
Typical PNNL recommendations in the kitchen include: Use of an ECM motor in walk-in cooler/freezer, additional insulation, waste heat recovery from refrigerant to preheat hot water etc.; reduced exhaust flow rate for ultra-efficient cooking appliances and efficient exhaust hoods; demand-controlled exhaust based on cooking appliance schedule; runaround coil heat recovery to preheat outdoor air with waste heat from kitchen exhaust hood; and use of a gas-fired condensing water heater with 95% thermal efficiency.
PNNL figures the payback for installing energy efficient equipment ranges from a little over a year in Miami restaurants to a little over three years in Chicago.
You can read the full report here: http://www.pnl.gov/main/publications/external/technical_reports/PNNL-19809.pdf