# ASTM F1787-98 (Reapproved 2015)

Designation: F1787 − 98 (Reapproved 2015) An American National StandardStandard Test Method forPerformance of Rotisserie Ovens1This standard is issued under the fixed designation F1787; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (´) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method evaluates the energy consumption andcooking performance of rotisserie ovens. The food serviceoperator can use this evaluation to select a rotisserie oven andunderstand its energy performance.1.2 This test method is applicable to thermostatically-controlled gas and electric rotisserie ovens designed for batchcooking.1.3 The rotisserie oven can be evaluated with respect to thefollowing (where applicable):1.3.1 Energy input rate (10.2),1.3.2 Preheat energy and time (10.4),1.3.3 Idle energy rate (10.5),1.3.4 Pilot energy rate, if applicable (10.6),1.3.5 Cooking energy efficiency and production capacity(10.9), and1.3.6 Holding energy rate and product shrinkage (optional,10.10),1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This test method does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ANSI Document:ANSI Standard Z83.11 American National Standard for GasFood Service Equipment22.2 ASHRAE Document:ASHRAE Guideline 2—1986 (RA90) Engineering Analysisof Experimental Data33. Terminology3.1 Definitions:3.1.1 cooking cavity, n—that portion of the appliance inwhich food products are heated or cooked.3.1.2 cooking energy, n—energy consumed by the rotisserieoven as it is used to cook whole chickens under heavy- andlight-load conditions.3.1.3 cooking energy effıciency, n—quantity of energy im-parted to the chickens and appropriate spits, expressed as apercentage of energy consumed by the rotisserie oven duringthe cooking event.3.1.4 cooking energy rate, n—average rate of energy con-sumption (Btu/h or kW) during the cooking energy efficiencytests.3.1.5 cook time, n—time required to cook thawed (38 to40°F) whole chickens as specified in 7.4 to an averagetemperature of 195°F during a cooking energy efficiency test.3.1.6 energy input rate, n—peak rate at which a rotisserieoven consumes energy (Btu/h or kW), typically reflectedduring preheat.3.1.7 idle energy rate, n—the rate of energy consumed(Btu/h or kW) by the rotisserie oven while “holding” or“idling” the cooking cavity at the thermostat set point.3.1.8 holding energy rate, n—the rate of energy consumed(Btu/h or kW) by the rotisserie oven while keeping cookedproduct warm for display or merchandising purposes.3.1.9 pilot energy rate, n—average rate of energy consump-tion (Btu/h) by a rotisserie oven’s continuous pilot (if appli-cable).3.1.10 preheat energy, n—amount of energy consumed bythe rotisserie oven while preheating the cooking cavity fromambient room temperature (75 6 5°F) to a calibrated 350°F.1This test method is under the jurisdiction of ASTM Committee F26 on FoodService Equipment and is the direct responsibility of Subcommittee F26.06 onProductivity and Energy Protocol.Current edition approved March 1, 2015. Published May 2015. Originallyapproved in 1997. Last previous edition approved in 2008 as F1787 – 98 (2008).DOI: 10.1520/F1787-98R15.2Available from the International Approval Services, Inc., 8501 E. PleasantValley Road, Cleveland, OH 44131.3Available from American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE), 1791 Tullie Circle, NE, Atlanta, GA30329.Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.11 preheat rate, n—average rate (°F/min) at which therotisserie oven’s cooking cavity is heated from ambient tem-perature (75 6 5°F) to 350°F.3.1.12 preheat time, n—time required for the rotisserie ovento preheat from ambient room temperature (75 6 5°F) to350°F.3.1.13 production capacity, n—maximum rate (lb/h) atwhich the rotisserie oven can bring thawed (38 to 40°F) wholechickens as specified in 7.4 to an average temperature of 195°F.3.1.14 production rate, n—rate (lb/h) at which the rotisserieoven brings thawed (38 to 40°F) whole chickens as specified in7.4 to an average temperature of 195°F. Does not necessarilyrefer to maximum rate. Production rate varies with the amountof food being cooked.3.1.15 product shrinkage, n—the reduction in net chickenweight (%) which occurs during holding.3.1.16 rotisserie oven, n—an appliance with a closed cavitydesigned for batch cooking, fitted with one or more spits thatare mechanically rotated past a fixed heat source while the foodis slowly being cooked on all sides.3.1.17 uncertainty, n—measure of systematic and precisionerrors in specified instrumentation or measure of repeatabilityof a reported test result.4. Summary of Test Method4.1 The rotisserie oven is connected to the appropriatemetered energy source, and energy input rate is determined toconfirm that the appliance is operating within 5 % of thenameplate energy input rate.4.2 The amount of energy and time required to preheat therotisserie oven to a calibrated 350°F thermostat set point isdetermined.4.3 The idle energy rate is determined with the rotisserieoven set to maintain 350°F in the cooking cavity.4.4 Pilot energy rate is determined, when applicable, for gasrotisserie ovens.4.5 The rotisserie oven is used to cook thawed, wholechickens to an average internal temperature of 195°F. Cookingenergy efficiency is determined for heavy- and light-loadconditions. Production capacity and product yield are deter-mined for the rotisserie oven based on the heavy-load cookingtest.NOTE 1—Surveys of national chains conducted by PG energy efficiency; performance; productioncapacity; rotisserie oven; shrinkage; test method; yieldANNEX(Mandatory Information)A1. PROCEDURE FOR DETERMINING THE UNCERTAINTY IN REPORTED TEST RESULTSNOTE A1.1—This procedure is based on the ASHRAE method fordetermining the confidence interval for the average of several test results(ASHRAE Guideline 2—1986 (RA90)). It should only be applied to testresults that have been obtained within the tolerances prescribed in this testmethod (for example, thermocouples calibrated, appliance operatingwithin 5 % of rated input during the test run).A1.1 For the cooking energy efficiency and productioncapacity results, the uncertainty in the averages of at least threetest runs is reported. For each loading scenario, the uncertaintyof the cooking energy efficiency and production capacity mustbe no greater than 610 % before any of the parameters for thatloading scenario can be reported.A1.2 The uncertainty in a reported result is a measure of itsprecision. If, for example, the production capacity for theappliance is 30 lb/h, the uncertainty must not be greater than63 lb/h. Thus, the true production capacity is between 27 and33 lb/h. This interval is determined at the 95 % confidencelevel, which means that there is onlya1in20chance that thetrue production capacity could be outside of this interval.A1.3 Calculating the uncertainty not only guarantees themaximum uncertainty in the reported results, but is also used todetermine how many test runs are needed to satisfy thisrequirement. The uncertainty is calculated from the standarddeviation of three or more test results and a factor from TableA1.1, which lists the number of test results used to calculate theaverage. The percent uncertainty is the ratio of the uncertaintyto the average expressed as a percent.A1.4 Procedure:TABLE A1.1 Uncertainty FactorsTest Results, n Uncertainty Factor, Cn3 2.484 1.595 1.246 1.057 0.928 0.849 0.7710 0.72F1787 − 98 (2015)8NOTE A1.2—Note A1.5 shows how to apply this procedure.A1.4.1 Step 1—Calculate the average and the standarddeviation for the test result (cooking-energy efficiency orproduction capacity) using the results of the first three test runs,as follows:A1.4.1.1 The formula for the average (three test runs) is asfollows:Xa35 ~1/3! 3 ~X11X21X3! (A1.1)where:Xa3= average of results for three test runs, andX1,X2,X3= results for each test run.A1.4.1.2 The formula for the sample standard deviation(three test runs) is as follows:S35 ~1/=2! 3=~A32 B3! (A1.2)where:S3= standard deviation of results for three test runs,A3=(X1)2+(X2)2+(X3)2, andB3= ~1/3!3~X11X21X3!2.NOTE A1.3—The formulas may be used to calculate the average andsample standard deviation. However, a calculator with statistical functionis recommended, in which case be sure to use the sample standarddeviation function. The population standard deviation function will resultin an error in the uncertainty.NOTE A1.4—The “A” quantity is the sum of the squares of each testresult, and the “B” quantity is the square of the sum of all test resultsmultiplied by a constant (1⁄3 in this case).A1.4.2 Step 2—Calculate the absolute uncertainty in theaverage for each parameter listed in Step 1. Multiply thestandard deviation calculated in Step 1 by the uncertaintyfactor corresponding to three test results from Table A1.1.A1.4.2.1 The formula for the absolute uncertainty (3 testruns) is as follows:U35 C33S3, (A1.3)U35 2.48 3S3where:U3= absolute uncertainty in average for three test runs, andC3= uncertainty factor for three test runs (Table A1.1).A1.4.3 Step 3—Calculate the percent uncertainty in eachparameter average using the averages from Step 1 and theabsolute uncertainties from Step 2.A1.4.3.1 The formula for the percent uncertainty (3 testruns) is as follows:%U35 ~U3/Xa3! 3100% (A1.4)where:%U3= percent uncertainty in average for three test runs,U3= absolute uncertainty in average for three test runs,andXa3= average of three test runs.A1.4.4 If the percent uncertainty, %U3, is not greater than 610 % for the cooking-energy efficiency and productioncapacity, report the average for these parameters along withtheir corresponding absolute uncertainty, U3, in the followingformat:Xa36U3If the percent uncertainty is greater than 610 % for thecooking energy efficiency or production capacity, proceed toStep 5.A1.4.5 Step 5—Run a fourth test for each loading scenariowhose percent uncertainty was greater than 610 %.A1.4.6 Step 6—When a fourth test is run for a given loadingscenario, calculate the average and standard deviation for testresults using a calculator or the following formulas:A1.4.6.1 The formula for the average (four test runs) is asfollows:Xa45 ~1/4! 3 ~X11X21X31X4! (A1.5)where:Xa4= average of results for four test runs, andX1,X2,X3,X4= results for each test run.A1.4.6.2 The formula for the standard deviation (four testruns) is as follows:S45 ~1/=3! 3=~A42 B4! (A1.6)where:S4= standard deviation of results for four test runs,A4=(X1)2+(X2)2+(X3)2+(X4)2, andB4= ~1/4!3~X11X21X31X4!2.A1.4.7 Step 7—Calculate the absolute uncertainty in theaverage for each parameter listed in Step 1. Multiply thestandard deviation calculated in Step 6 by the uncertaintyfactor for four test results from Table A1.1.A1.4.7.1 The formula for the absolute uncertainty (four testruns) is as follows:U45 C43S4, (A1.7)U45 1.59 3S4where:U4= absolute uncertainty in average for four test runs, andC4= the uncertainty factor for four test runs (Table A1.1).A1.4.8 Step 8—Calculate the percent uncertainty in theparameter averages using the averages from Step 6 and theabsolute uncertainties from Step 7.A1.4.8.1 The formula for the percent uncertainty (four testruns) is as follows:%U45 ~U4/Xa4! 3100% (A1.8)where:%U4= percent uncertainty in average for four test runs,U4= absolute uncertainty in average for four test runs, andXa4= average of four test runs.A1.4.9 Step 9—If the percent uncertainty, %U4,isnotgreater than 610 % for the cooking energy efficiency andproduction capacity, report the average for these parametersalong with their corresponding absolute uncertainty, U4,inthefollowing format:Xa46U4F1787 − 98 (2015)9If the percent uncertainty is greater than 6 10 % for thecooking energy efficiency or production capacity, proceed toStep 10.A1.4.10 Step 10—The steps required for five or more testruns are the same as those described above. More generalformulas are listed below for calculating the average, standarddeviation, absolute uncertainty, and percent uncertainty.A1.4.10.1 The formula for the average (n test runs) is asfollows:Xan5 ~1/n! 3 ~X11X21X31X41…1Xn! (A1.9)where:n = number of test runs,Xan= average of results n test runs, andX1,X2,X3,X4, . Xn= results for each test run.A1.4.10.2 The formula for the standard deviation (n testruns) is as follows:Sn5 ~1/=~n 2 1!! 3 ~= ~An2 Bn!! (A1.10)where:Sn= standard deviation of results for n test runs,An=(X1)2+(X2)2+(X3)2+(X4)2+.+(Xn)2, andBn= (1/n)×(X1+ X2+ X3+ X4+ . + Xn)2.A1.4.10.3 The formula for the absolute uncertainty (n testruns) is as follows:Un5 Cn3Sn(A1.11)where:Un= absolute uncertainty in average for n test runs, andCn= uncertainty factor for n test runs (Table A1.1).A1.4.10.4 The formula for the percent uncertainty (n testruns) is as follows:%Un5 ~Un/Xan! 3100% (A1.12)where:%Un= percent uncertainty in average for n test runs,Un= absolute uncertainty in average for n test runs, andXan= average of n test runs.When the percent uncertainty, %Un, is less than or equal to6 10 % for the cooking energy efficiency and productioncapacity, report the average for these parameters along withtheir corresponding absolute uncertainty, Un, in the followingformat:Xan6UnNOTE A1.5—The researcher may compute a test result that deviatessignificantly from the other test results. Such a result should be discardedonly if there is some physical evidence that the test run was not performedaccording to the conditions specified in this method. For example, athermocouple was out of calibration, the appliance’s input capacity wasnot within 5 % of the rated input, or the food product was not withinspecification. To assure that all results are obtained under approximatelythe same conditions, it is good practice to monitor those test conditionsspecified in this method.A1.5 Example of Determining Uncertainty in Average TestResult:A1.5.1 Three test runs for the full-load cooking scenarioyielded the following production capacity (PC) results:Test PCRun No. 1 33.8 lb/hRun No. 2 34.1 lb/hRun No. 3 31.0 lb/hA1.5.2 Step 1—Calculate the average and standard devia-tion of the three test results for the PC.A1.5.2.1 The average of the three test results is as follows:Xa35 ~1/3! 3 ~X11X21X3!, (A1.13)Xa35 ~1/3! 3 ~33.8134.1131.0!,Xa35 33.0 lb/hA1.5.2.2 The standard deviation of the three test results is asfol