DishwasherSurveyReview&TestProcedureRecommendationsOfFICE0!BUIIDINGSt*TCANDCOMMUNITYPROCAUMSArthurD.Little,Inc.AcornParkCambridge,Massachusetts02140-2390December4,2001Overviewjbl20301DishwasherSurveyReview1Dishwasher Survey Review Executive Summary The findings

of this review of available data on households’ dishwasher usage

habits show broad support

to define: • Households’ pretreatment methods, • Distribution

of households

by

the level of soil in a dishwasher load, • Quantitative

amounts
of soil on the dish ware, and • Frequency

of households’
use of a dishwasher. Two key

recommendations

are drawn from these survey findings,

the existing

test method for dishwashers, and ANSI/A HAM Standard DW-1: • A weighted, three-point

test method using

different numbers
of soiled dish ware is recommended

to measure the energy consumption

of soil-sensing

dishwashers. • The number
of average-use cycles per year

is recommended

to be reduced

to 203.jbl20301DishwasherSurveyReview2DishwasherSurveyReviewNeededRevisions Technology-driven change

and change

in households’
use of dishwashers
has motivated the need for revision

to the test procedure

for the energy

and water consumption

of dishwashers

(10 CFR 430.23(c)). • The current dishwasher test method, using

a test load of clean dishes, does not yield measures representative

of the total per-cycle energy consumption

of a soil-sensing

dishwasher

in household use. • Publicly available data indicates that the representative average-use cycles per year
is overstated.jbl20301DishwasherSurveyReview3Dishwasher Survey Review Support Data Requirements To address the needed test procedure

revisions there are several key questions:

• How soiled are the dishes

in the dishwashers

of U.S. households?- Quantity

of soil?- Types

of soil? • How loaded are the dishwashers

in U.S. households?- Quantity

of dishware?- Type

of dishware? • How to reflect that soiling

in a modified energy consumption

test method? • How often do U.S. households use
a dishwasher?ajbl20301DishwasherSurveyReview

4Dishwasher Survey Review Data Sources The findings and recommendations

of this review are based on: 1) Review
of existing industry

and DOE dishwasher test standards; 2) Review and analysis

of survey

information from ght individual sources including

dishwasher and detergent manufacturers, energy

and consumer interest groups, independent researchers,
and government agencies;

and 3) Discussions with key personnel

in industry, DOE, NIST, consumers groups,

and Arthur
D. Little.jb120301DishwasherSurveyReview5Dishwasher Survey Review Data Sources A key requirement

of this review

is to maintain the confidentiality

of the industry survey

sources.
To this end no one industry

source

is referenced and the data presented

is an aggregation

of the information in the following surveys. Survey

Sco

e Number

of Breadth
of Quality
of Identifier

p Households Information Information Survey

A Nationally Representative

> 8,000 Wide

High Survey

B Nationally Representative

> 6,000
Wide

High Survey

C Nationally Representative

<

1 ,000 Wide

High Survey

D Regional

> 1,000 Limited Moderate Survey

E Regional

< 250 Limited

Low Survey

F Regional

< 250 Moderate Moderate Survey

G Nationally Representative

< 500 Moderate Moderate Survey

H Nationally Representative

<

1 ,000 Moderate Moderate 1997 RECS Nationally Representative
5,900 Limited

High jbl 20301 Dishwasher Survey Review

6Dishwasher Survey Review Detailed Findings- Soil-based Test How soiled are the dishes

in the dishwashers

of U.S. households? Quantity

of soil?- Drawn from data on:- Pretreatment methods and the resultant soil levels on dishware,- Qualitative ranking

of soil level, and- Assessment

of quantitative

amounts

of soil associated with the Qualitative ranking

of soil level. • Type of soil?- Drawn from data in existing industry standards

jbl 20301 Dishwasher Survey Review

7Dishwasher Survey Review Pretreatment Methods Over 70% of U.S. households pretreat dishes with water before loading into the dishwasher. 80.0%
Over 70% of consumers pretreat dishes 70.0%

with water before loading into dishwasher.60.00/ef 50.0% 40.0% 30.0% 20.0% 10.0% 0.0%-I _____I1



# I

1 Pre-rinse with Pre-wash, including Pre-soak the dish Scrape food without Removed large

Do nothing water some scrubbing

water scraps Pretreatment Methodjbl20301DishwasherSurveyReview

8Dishwasher Survey Review Levels
of Soil U.S. households distribute

in three levels of soil- Light,

Medium and Heavy. 70%

62% 60% U,r o’ .t DUb 

# I 2

40% 

# j 30%- u. 20% D

5% 0%-I Light

Medium

Heavy Soil Level

jbl 20301 Dishwasher Survey Review

9Dishwasher Survey Review Types
of Soil 

# The industry-recognized,

‘worst-case’ cleaning performance test, ANSI/AHAM Standard DW-1, precisely

defines:

1) food soils that are representative

of the types

of soils on the dishware

of U.S. households;

2) amounts

of those food soils; and 3) procedures

to apply

the food soils and to prepare

the dishware for testing. 

# 1[ _I. :t ‘‘‘“

jbl 20301 Dishwasher Survey Review

10DishwasherSurveyReviewQuantitativeAmountsofSoilQuantitativeamountsofsoilondishwareareexpressedintermsofthenumberofplacesettingssoiledperDW-1andarerelatedtothethreelevelsofsoil.Thereisawiderangeinthesurveydataontherepresentativeamountsofsoilcorrespondingtothethreesoillevels.SoilAmountsintermsofPlaceSettingsSoiledPerDW-1LightMediumHeavySurveyC1/2of124-5SurveyD1-24-66-8SurveyF148jol2030DishwasherSurveyReview11Dishwasher Survey Review Quantitative Amounts

of Soil Aggregating
the survey data yields conservative values for the representative amounts

of soil corresponding

to the three soil levels. 100%-

- 90%

Heavy Soil Level- 6 Soiled Place Settings 80%

--—----

-• MediumSoilLevel o- 3 Soiled Place Settings Cl) ______________ 70% Light Soil Level-
1 Soiled Place Setting 9____________________ 60%

(

---•-C g 50%

-U,0 40% >1 030%-‘I04-C 20%

-- 10%0%—----r———-—1— ——-——--—-n----———------i-_——— 1/2

1

2

2

4

6

5

8 Nunl,er
of Place Settings

in the DOE Test Load Soiled cording

to DW-1jbl20301DishwasherSurveyReview

12Dishwasher Survey Review Amount

& Type of Dishware How loaded are the dishwashers

in U.S. households? Quantity

of dishware?- Vast majority
of households (>80%) run dishwashers

at full capacity.- In conjunction with average operation

of about once every other day, implies that some portion, -112, of the dishware load with varying levels of soil is air-drying
for about

a day.- ANSI/AHAM Standard DW-1
is being revised
to consider longer air-drying of soiled dishware. Type of dishware?- As might be expected, there
is a wide variety
of dishware used in U.S. households.- One nationally representative survey indicates that for >50% of households plastic dishware makes up 25% or more of the load.- Any impact

is likely to be of secondary importance

to implementing

a soil-based test method for soil-sensing dishwashers.jbl20301DishwasherSurveyReview

13DishwasherSurveyReviewProposedTestMethodforSoil-SensingDishwashersApplyingonlytosoil-sensingdishwashers,arevisedtestmethodwouldrequire3energyconsumptiontestsusingdifferentnumbersofsoileddishware:SoiledPlaceSettingsCleanPlaceSettingsTestSoilLevelperAHAMStandardperAHAMStandardTotalPlaceSettingsNumberDW-1DW-11Light1782Medium3583Heavy628Theenergyfactorwouldbeaweightedaverageofthe3testsusingthepercentagesforthedistributionofU.S.householdsinthethreesoillevelcategories-62%Light,33%Medium,5%Heavy:EFsoiisensing=1/((.62*Test#1Energy)+(.33*Test#2Energy)+(.05*Test#3Energy))jbl20301DishwasherSurveyReview14Dishwasher Survey Review Frequency

of Use How often do U.S. households use
a dishwasher?- A lot less according

to EIA ‘s 1997 RECS. 60.0%

EIA’s 1997 RECS 50.0%

Median: Half of the responses are at less than

4 times per week, or less than 208 cycles per year. Average: Can range from 207 to 40.0%

282 cycles per year depending

on definition

of the categories. 300% (0 20.0%- 10.0% 0.0%
Less Than

4 Times

4 to 6 Times

At Least Once Each Day jbl 20301 Dishwasher Survey Review

15DishwasherSurveyReviewFrequencyofUseU,1 A weighted average

of five nationally representative surveys yields 203 average-use cycles per year

for dishwashers.



# -Median:halfoftheresponsesareat3.53/weekorlessI.e.—184cyclesperyearorless.-Average:inaggregate,theaverageis3.91cyclesperweekor—203cyclesper16%-14%12%10%8%6%4%2%0%-,1-rj — (çD , ._$l-?f‘-1I n

nn 

# zfl* njbl20301DishwasherSurveyReview16p Dishwasher Survey Review Recommendations Arthur
D. Little’s recommendations

on revisions

to the energy consumption

test procedure

for dishwashers include: • Creating

a separate path in the test method fo soi[sensing dishwashers
and adopting

the weighted three-point test method prevusIy outlined, and • Reducing the average-use cycles per year for dishwashers

to 203 cycles per year. In addition, there are several recommendations

for future opportunities:

• Assessing

the energy impact
of pretreating dishes and the energy savings
of greater

utilization

of dishwashers, • Supporting industry efforts
to update and maintain ANSI/AHAM Standard DW-1, • Assessing

the energy impact
of plastic dishware

in the test load, and • Monitoring

households’ dishwasher usage habits and characteristics through

future survey reviews.jbl20301DishwasherSurveyReview17