Survey Review & Test

ecommendations

OfFICE 0!

BUIIDING

St*TC AND COMMUNITY PROCAUMS

Arthur D. Little, Inc.Acorn Park

Cambridge,

Massachusetts

02140-2390

December 4, 2001
jbl 20301 Dishwasher Survey Review 1
urvey Review Executive Summary

s of this review of available data on households’ dishwasher

ts show broad support to define:

eholds’ pretreatment methods,

bution of households by the level ofsoil in a dishwasher load,

titative amounts ofsoil on the dishware, and

uency of households’ use of a dishwasher.

commendations are drawn from these survey findings, the

t method for dishwashers, and ANSI/AHAM Standard DW-1:

ghted, three-point test method using different numbers of

d dishware is recommended to measure the energy

mption ofsoil-sensing dishwashers.

number of average-use cycles per year is recommended to be

ced to 203.

jbl 20301 Dishwasher Survey Review 2
urvey Review Needed Revisions

y-driven change and change in households’ use of

rs has motivated the need for revision to the test procedure for

and water consumption of dishwashers (10 CFR 430.23(c)).

urrent dishwasher test method, using a test load of clean dishes,

not yield measures representative of the total per-cycle energy

mption of a soil-sensing dishwasher in household use.

cly available data indicates that the representative average-use

s per year is overstated.

jbl 20301 Dishwasher Survey Review 3
urvey Review Support Data Requirements

the needed test procedure revisions there are several key

oiled are the dishes in the dishwashers of U.S. households?

uantity of soil?

ypes of soil?

oaded are the dishwashers in U.S. households?

uantity of dishware?

ype of dishware?

o reflect that soiling in a modified energy consumption test method?

often do U.S. households use a dishwasher?a

jbl 20301 Dishwasher Survey Review 4
urvey Review Data Sources

gs and recommendations of this review are based on:

ew of existing industry and DOE dishwasher test standards;

ew and analysis of survey information from ght individual sources

ding dishwasher and detergent manufacturers, energy and

umer interest groups, independent researchers, and government

ncies; and

ussions with key personnel in industry, DOE, NIST, consumers

ps, and Arthur D. Little.

jb120301 Dishwasher Survey Review 5
Survey Review Data Sources

uirement of this review is to maintain the confidentiality of the

urvey sources. To this end no one industry source is

d and the data presented is an aggregation of the information

owing surveys.

Sco e Number of Breadth of Quality of 

p Households Information Information

Nationally Representative > 8,000 Wide High

Nationally Representative > 6,000 Wide High

Nationally Representative < 1 ,000 Wide High

Regional > 1,000 Limited Moderate

Regional < 250 Limited Low

Regional < 250 Moderate Moderate

Nationally Representative < 500 Moderate Moderate

Nationally Representative < 1 ,000 Moderate Moderate

Nationally Representative 5,900 Limited High

jbl 20301 Dishwasher Survey Review 6
Survey Review Detailed Findings -Soil-based Test

d are the dishes in the dishwashers of U.S. households?

tity 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.

of soil?

Drawn from data in existing industry standards

jbl 20301 Dishwasher Survey Review 7
Survey Review Pretreatment Methods

% of U.S. households pretreat dishes with water before loading

dishwasher.

Over 70% of consumers pretreat dishes

with water before loading into dishwasher.

I

_____

I 1 I 1

rinse with Pre-wash, including Pre-soak the dish Scrape food without Removed large Do nothing

water some scrubbing water scraps

Pretreatment Method

jbl 20301 Dishwasher Survey Review 8
Survey Review Levels of Soil

seholds distribute in three levels of soil - Light, Medium and

62%

5%

I

Light Medium Heavy

Soil Level

jbl 20301 Dishwasher Survey Review 9
r Survey Review Types of Soil

ustry-recognized, ‘worst-case’ cleaning performance test,

AM Standard DW-1, precisely defines: 1) food soils that are

ntative of the types of soils on the dishware of U.S.

lds; 2) amounts of those food soils; and 3) procedures to

e food soils and to prepare the dishware for testing.

1[ _I.

:t ‘‘‘“

jbl 20301 Dishwasher Survey Review 10
Survey Review Quantitative Amounts of Soil

ive amounts of soil on dishware are expressed in terms of the

of place settings soiled per DW-1 and are related to the three

soil. There is a wide range in the survey data on the

tative amounts of soil corresponding to the three soil levels.

Soil Amounts in terms of Place Settings Soiled Per DW-1

Light Medium Heavy

C 1/2 of 1 2 4-5

D 1-2 4-6 6-8

F 1 4 8

jol 2030 Dishwasher Survey Review 1 1
Survey Review Quantitative Amounts of Soil

ing the survey data yields conservative values for the

tative amounts of soil corresponding to the three soil levels.

Heavy Soil Level

- 6 Soiled Place Settings

—----

-• MediumSoilLevel

- 3 Soiled Place Settings

______________

Light Soil Level

- 1 Soiled Place Setting

_______ __________

- --•- 

-

- 

— ----r— — —-— 1— ——-— — --—-n----— — —------i-_—— —

1 2 2 4 6 5 8

Nunl,er of Place Settings in the DOE Test Load Soiled cording to DW-1

jbl 20301 Dishwasher Survey Review 12
Survey Review Amount & Type of Dishware

ed are the dishwashers in U.S. households?

ntity 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.

e 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.

jbl 20301 Dishwasher Survey Review 13
r Survey Review Proposed Test Method for Soil-Sensing Dishwashers

only to soil-sensing dishwashers, a revised test method

quire 3 energy consumption tests using different numbers of

shware:

Soiled Place Settings Clean Place Settings 

il Level per AHAM Standard per AHAM Standard Total Place Settings 

DW-1 DW-1

Light 1 7 8

Medium 3 5 8

Heavy 6 2 8

gy factor would be a weighted average of the 3 tests using the

ges for the distribution of U.S. households in the three soil

egories - 62% Light, 33% Medium, 5% Heavy:

ng = 1/((. 62*Test# 1 Energy)+(. 33*Test#2 Energy)+(. 05*Test#3 Energy))

jbl 20301 Dishwasher Survey Review 14
urvey Review Frequency of Use

do U.S. households use a dishwasher? - A lot less

to EIA ‘s 1997 RECS.

EIA’s 1997 RECS

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

282 cycles per year depending on

definition of the categories.

Less Than 4 Times 4 to 6 Times At Least Once Each Day

jbl 20301 Dishwasher Survey Review 15
Survey Review Frequency of Use

d average of five nationally representative surveys yields 203

se cycles per year for dishwashers.

-

Median: half of the responses are at

3.53/week or less I.e. —184 cycles per yearor less.

- Average: in aggregate, the average is

3.91 cycles per week or —203 cycles per

- , 1- rj — (ç D

$l-?f

I

n n n n zfl*

jbl 20301 Dishwasher Survey Review 16
Survey Review Recommendations

Little’s recommendations on revisions to the energy

ion test procedure for dishwashers include:

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

ing the weighted three-point test method prevusIy outlined, and

cing the average-use cycles per year for dishwashers to 203 cycles per

n, there are several recommendations for future

ties:

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

er utilization of dishwashers,

orting industry efforts to update and maintain ANSI/AHAM Standard

,

ssing the energy impact of plastic dishware in the test load, and

toring households’ dishwasher usage habits and characteristics

gh future survey reviews.

jbl 20301 Dishwasher Survey Review 1 7