key_points

  • Significant savings can be found in ENERGY STAR-qualified appliances.
  • The Fisher-Nickel Food Service Technology Center (FSTC) offers life cycle cost calculators for various cooking equipment.
  • The use of hot-food-holding cabinets is another cooking technique that can reduce overall energy use.

Electric cooking appliances are generally very efficient, though the following suggestions may help to further reduce energy costs.

  • Upgrade equipment or change operating procedures to reduce energy costs. Significant savings can be found in ENERGY STAR-qualified appliances.
  • Under part-load operation, electric fryers and griddles have proven more energy efficient than gas fryers and griddles. Under idle conditions, the energy consumed by a gas unit may exceed that of an electric unit by a factor of three or more.
  • Use TRIAC controls for regulation of energy. The TRIAC is a three-terminal device that controls and conducts current flow to ensure that the proper amount of power is being used.
  • Flat ribbon, low-watt-density heating elements consume less energy and have longer lives than traditional round calrod heating elements.
  • Add insulation or upgrade insulation for electric units. Improved compartment insulation on steamers and kettles reduces heat loss to the kitchen and standby energy consumption.
  • Incorporate demand ventilation, which modulates the range hood and makeup air fan speeds using infrared sensors and variable speed motors. A case study has shown a 60% decrease in demand (kW) and energy (kWh) consumption, as well as an equivalent savings in heating of outdoor makeup air using this technology.
  • Use energy-efficient exhaust hoods that use outside air rather than inside conditioned air for ventilation.
  • Side curtains around cooking equipment can help restrict the flow of conditioned air to the outside.

An ENERGY-STAR-qualified electric open-deep fat fryer must meet a minimum cooking efficiency of 80%, and also meet a maximum idle energy rate of 1,000 watts. In addition to shorter cooking times, a commercial restaurant may be able to increase production throughput with more energy-efficient appliances. The user may also want to consider frypot insulation to further reduce standby losses and to lower the idle energy rate. The Fisher-Nickel Food Service Technology Center (FSTC) offers life cycle cost calculators, including one for electric fryers.

The use of hot-food-holding cabinets is another cooking technique that can reduce overall energy use. An ENERGY STAR unit must meet a maximum idle energy rate of 40 watts/cubic foot, and is generally 50% to 60% more energy efficient than standard models. Models that meet this requirement incorporate better insulation, which reduces heat loss, and may also offer additional energy-saving devices such as magnetic door gaskets, auto-door closures, or dutch doors. The insulation of the cabinet also offers better temperature uniformity within the cabinet from top to bottom. FSTC’s hot-food-holding cabinet cost calculator provides a means to compare various designs.

Electric steam cookers can also achieve ENERGY STAR ratings if they meet a minimum cooking efficiency of 50% while also meeting maximum idle energy rates. Idle energy rates are specified for 3-, 4-, 5-, and 6-pan sizes. These more efficient units use considerably less water (in some cases almost 90% less—from 25 gallons per hour down to 3 gallons per hour for the top rated units). This lower water use can add up in a busy commercial cooking establishment, and will also lower the facility’s water utility bills. The FSTC offers an electric steamer life cycle cost calculator on its Web site.

A commercial kitchen will also include refrigeration equipment. Where possible, the end user should select the more energy-efficient solid door, as well as reach-in refrigerators and freezers that are designed with components such as Electronically Commutated Motor (ECM) evaporator and condenser fan motors, hot gas anti-sweat heaters, or high-efficiency compressors, all of which will significantly reduce energy consumption and utility bills. Compared to standard models, ENERGY-STAR-labeled commercial solid door refrigerators and freezers can be 40% to 50% more energy efficient compared to standard models. FSTC also provides a helpful cost calculator on refrigerators so that the restaurant owners can do their own analysis.

Comparison of Energy Consumption for Gas & Electric Cooking Appliances
Gas Electric
Capacity Operating Hours per Day (h/d) Duty Cycle (%) Annual Energy (kBtu) Duty Cycle (%) Annual Energy (kBtu) Annual Energy (kWh)
Fryers
Open Deep Fat 35-50 lb 12 20% 74,900 20% 38,300 11,200
Pressure/Kettle 30-50 lb 10 30% 56,600 33% 21,300 6,200
Flat Bottom – Chicken/Fish 125 lb. 10 30% 168,000 20% 53,200 15,600
Flat Bottom – Donut 80 lb 8 20% 34,900 14% 17,000 4,985
Griddles
Single-sided 3-foot 12 34%> 86,100 24% 38,300 11,232
Broilers
Underfired 3-foot 8 80% 210,000 70% 85,200 24,960
Overfired 3-foot 8 70% 115,000 70% 74,500 21,840
Ranges
Range Top 6 Burner 12 20% 120,000 25% 38,300 11,200
Range Oven 8 40% 39,900 25% 17,000 4,990
Chinese Range 2 Wok 10 30% 187,000
Ovens
Standard 38 X 38 8 35% 62,400 25% 42,600 12,500
Deck 10 30% 65,500 20% 21,300 6,240
Conveyor 10 50% 212,000 50% 213,000 62,400
Rotisserie 8 60% 74,900 65% 42,600 12,500
Steamers (boiler*)
Pressure* 6 Pan 14 15% 140,000 12% 74,500 21,800
Pressureless* 6 Pan 14 15% 140,000 20% 74,500 21,800
Connectionless 6 Pan 14 14% 37,300 10,920
Kettles, Steam 60 Gal. 4 40% 62,400 40% 34,000 9,980
Braising Pan 30 Gal. 4 45% 49,900 60% 29,800 8,730
Source: Commercial Kitchen Appliance Technology Assessment, Food Service Technology Center, 2002
<< Back to Blog