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Restaurant electricity cost

Restaurants use energy differently and more intensively than most businesses. In the low desert climates cooling andinterior lighting are the biggest energy users at about 17% of total cost each, followed by refrigeration, cooking andventilation at about 13% each. These five uses account for 75% of the energy used in a typical sit-down restaurant. In aquick-service restaurant they account for over 80% of the energy. The following chart provides a breakdown of the annualcost of electricity for sit-down and quick-service restaurants. It is based on a survey of APS small office customers andcan be used as a guide for determining how energy is used in your restaurant.

Annual Electricity Cost for Typical Restaurants in the Phoenix Area

Electric End Use

Annual cost per square

foot For a Sit-Down

Restaurant

Annual cost per Square

Foot for a Quick-Service

Restaurant

Interior lighting $0.60 $1.07

Space Cooling $0.60 $1.48

Miscellaneous $0.43 $0.75

Ventilation $0.46 $0.92

Exterior lighting $0.12 $0.32

Refrigeration $0.45 $1.01

Cooking $0.46 $0.80

Water heating $0.32 $0.15

Total $3.44 $6.50

Lighting

Lighting has an important influence on ambience, function and operating cost. When examining your lighting system,consider the following issues:

Quantity The Illuminating Engineering Society (IES) recommends lighting levels for restaurants of 5 to 30footcandles for dining areas and 70 footcandles for kitchens. Quick-service restaurants have recommended lightinglevel of 100 footcandles. It is common to have more light than is needed. If there is too much light remove some ofthe lamps from the fixtures, or change to smaller wattage lamps. Footcandles can be measured with a light meteravailable at photography stores.

Quality If you want a warm relaxed atmosphere choose lamps that provide a low intensity and produce a warmlight. Warm light is considered to be light with the longer wave, or red portion of the spectrum dominant. If you wanta high energy atmosphere choose lamps to provide high intensities and cold light. Cold light is considered to be

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light with shorter wave, or where the blue portion of the spectrum is dominant. You may not notice a difference whenlooking at the light, but colors will appear different.

Efficiency The table below compares the efficiency and other features of common light sources used in restaurantapplications.

Characteristics of Common Light Sources1

Light Source

Efficiency

(Lumens/Watt)

Average Lamp

Life (Hours)2Color Rendering

Index*

Standard Incandescent 5-20 750-1000 100

Tungsten-Halogen (halogen) 15-25 2000-4000 100

Halogen Infrared Reflecting 20-35 2000-3000 100

Compact Fluorescent (5-26 watts) 20-55 10,000 80

Compact Fluorescent (27-40 watts) 50-80 15,000-20,000 80

Tubular Fluorescent 60-100 15,000-24,000 50-90

Metal Halide 45-100 10,000-20,000 60-90

Compact Metal Halide 45-80 5000-10,000 60-90

CRI is a measure of light quality. 100 is considered to be nearly equal to natural daylight. Lower values tend to makecolors look faded or washed out. CRI values of 80+ are considered to have good color rendering properties. CorrelatedColor Temperature (CCT) is another measure of light quality. High CCT highlights blue colors; low CCT highlights redcolors.

Cost There are three factors in the cost of lighting: purchase cost, operating and maintenance. As a general rule 90%of the cost is in the energy used and 10% is in the cost of the equipment, so it pays to select energy efficientequipment. The table below provides a brief comparison of the annual operating costs of some of the most commonlighting fixtures in restaurant applications, and the savings you might expect with their energy-efficient alternative.You can use these values to estimate the savings that could be gained at your facility. The least efficient lamp will use

66% more energy to produce the same amount of light as the most efficient. Selecting the most efficient lamp cansave $400-$500 per year per 1,000 square feet of space compared to the least efficient. The more efficient lampsproduce less heat and reduce the cooling load. That can add $100 to $175 per 1,000 square foot per year to the coolingcost. Total energy savings available by using the most efficient lamps compared to the least efficient are $500 to $675per 1,000 square foot per year. Maintenance costs and the hassle factor of lamp replacement can be reduced byselecting light sources with longer lives. For example, compact fluorescent lamps cost more to purchase thanincandescents but they last up to ten times as long thus reducing replacement costs. Halogen lamps tend to havelonger lives than standard incandescent lamps, and long-life versions of standard incandescent lamps are alsoavailable.

1Lighting Fundamentals Handbook, EPRI, 1992.

2 Lamp life ratings of incandescent lamps are based on three hours of use per start. Turning incandescent lamps on and off morefrequently will shorten their life.

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Comparison of Energy-Efficient Restaurant Lighting Options

FixtureTypical Annual Energy

Cost per Fixture

Savings With Energy-

Efficient Option

Standard 3-lamp T12 fluorescent fixture $60

Energy-efficient 3-lamp T8 fluorescent fixture $39 $21

Standard 75 watt incandescent downlight $34

Energy-efficient 20 watt compact fluorescent downlight $9 $25

Standard 90 watt halogen PAR flood light $41

Energy-efficient 60 watt halogen infra-red PAR flood light $27 $14

Space cooling

In low desert Arizona, cooling is a major energy user in restaurant applications. Cooling costs are approximately $550 and$1,350 per 1,000 square foot per year for sit down and quick service respectively. The cost of cooling is greatly influencedby other uses. Heat generated by lights and cooking and cool air lost through kitchen exhausts increases cooling costs. Tocontrol cooling costs, consider the following steps:

Maintain air-conditioning equipment Air conditioning equipment is often out of sight, out of mind, and you are

not in the AC maintenance business. Ask your air conditioning contractor to give you a proposal for a preventivemaintenance plan to keep it operating efficiently. See the For More Information section at the end of this sheet forinstructions on how to find other fact sheets, one of which deals specifically with air conditioning.

Ventilation

Ventilation is an important factor in maintaining comfort and controlling odors. It should maintain the kitchen at a slightnegative pressure with respect to the dining area to keep heat and cooking odors confined to the kitchen. Restaurantsrequire large quantities of ventilation air for both kitchen and dining areas. This can be an expensive proposition since theventilation air often needs to be heated and/or cooled to maintain comfort. There are two main components to ventilationcosts the cost of the fan energy to move the air required for ventilation and the cost to condition (cool or heat) the make-

up air that replaces that which has been removed. These costs can be minimized by good kitchen hood and ventilationsystem design. While this topic goes beyond the scope of this fact sheet the following general guidelines apply:

Optimize the quantity of ventilation air Many commercial kitchen ventilation systems were designed by rules-of-thumb such as 100 cubic feet per minute (CFM) of airflow per square foot of hood capture area. This may be more airthan required, and the same quantity of air may not be needed all the time. For example, different levels of ventilationapply when actual cooking is in process compared to other times of general preparation. Also, one manufacturersuggests that sizing ventilation systems based on the ventilation needs of specific pieces of food preparationequipment could reduce ventilation requirements by one third, saving significantly on ventilation costs. Check yourlocal codes and ventilation equipment manufacturers to see if your ventilation rates can be reduced and still do thejob.

Optimize the cost of conditioning make up air Air conditioning costs can be minimized by introducing

unconditioned make up air near the kitchen hood where air is exhausted. This will minimize the amount ofconditioned air exhausted at the hood. For tempering hot outdoor makeup air, an evaporative cooler can be a cost-effective option for most of the year in the low desert region. Without make up air you could be exhaustingheated/cooled air costing hundreds of dollars a month.

What about heat recovery systems? While some commercial kitchen ventilation equipment manufacturers areworking on heat recovery systems for kitchen ventilation, kitchen heat recovery is not practical with currenttechnology. This is primarily due to grease buildup in the exhaust system which limits heat transfer. Manufacturersare working on advanced grease filtration systems to make heat recovery more feasible. Heat recovery for fresh airventilation of dining areas is feasible, however, and can reduce air conditioning costs.

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Non smoking sections Some restaurants dont effectively isolate non-smoking sections. Its difficult to keep thesmoke odor out if the same air conditioner serves smoking and non-smoking. Get separate air conditioners and get anair balance professional to adjust them so air from the smoking section does not enter the non-smoking section. Keepthe non-smoking section under a slight positive pressure to keep the smoke out.

Cooking

Whether using electric or gas, the basic principles for cooking energy conservation are the same. Turn it off when not in

use, and exhaust the heat and moisture as efficiently as possible. Use the lowest heat setting that will do the job, and avoidexcessive equipment warm-up periods. Most equipment will warm up in a few seconds to a few minutes. When choosingkitchen equipment consider that some are more efficient than others. For example, microwave ovens are more efficientthan standard and convection ovens. If possible, stagger run times of heavy-duty electric cooking equipment to keepdemand charges down. See the For More Information section at the end of this sheet for instructions on how to findother fact sheets, one of which deals specifically with cooking.

Refrigeration

The annual cost of food storage refrigeration is estimated to be about $460 and $1,040 per 1,000 sq. ft. per year for sitdown and quick service restaurants respectively. High-efficiency equipment can save up to 50% on energy costs. When

specifying new or replacement refrigeration equipment look for features such as high-efficiency fan motors, high-efficiency compressors, energy-efficient anti-sweat heater controls, and high-efficiency lighting. See the For MoreInformation section at the end of this sheet for instructions on how to find other fact sheets, one of which dealsspecifically with food storage refrigeration.

Water heating

Heat pump water heaters can be used to cool the kitchen and provide free hot water. They use the heat removed fromthe kitchen air to heat the water, so the hot water is a free by product of cooling the kitchen. Commercial kitchens are oneof the few places where heat pump water heaters are a good application, consequently there is not much of a market forthem and they are hard to find. Use your web search engine to look for heat pump water heater, or ask your airconditioning or plumbing contractor for sources.

For more information

For additional information on a variety of energy topics go to www.aps.comand select business/more options/ways tosave and click on one of the Energy Answers for your Business fact sheets. For a more detailed analysis, click onEnergy Survey. You can input the information for your facility and get a comparison to similar businesses along withspecific suggestions on ways to improve energy use.

Some of the best resources of information on lighting, ventilation sources and other restaurant applications are often yourequipment suppliers. Most major manufacturers also have excellent information on their websites. For lightinginformation visit the Lighting Research Center at http://www.lrc.rpi.edu/. Some very interesting information can be foundat the Commercial Kitchen Ventilation (CKV) Lab at www.archenergy.com/ckv.

http://www.aps.com/http://www.aps.com/http://www.lrc.rpi.edu/http://www.lrc.rpi.edu/http://www.archenergy.com/ckvhttp://www.archenergy.com/ckvhttp://www.archenergy.com/ckvhttp://www.lrc.rpi.edu/http://www.aps.com/