APPENDIX 7A. LOAD USAGE FACTOR IN COMMERCIAL LAUNDRY 

APPLICATIONS

TABLE OF CONTENTS

7A.1 INTRODUCTION .......................................................................................................7-A-2

7A.2 METHODOLOGY AND DATA.................................................................................7-A-2

7A.3 FINDINGS...................................................................................................................7-A-3

LIST OF TABLES

Table 7A.1.1 Load Usage Factors from the Test Procedure..................................................7-A-2

Table 7A.2.1 Cal UCONS Commercial Laundry Program: Number of monitored days 

for each washer ................................................................................................7-A-3

Table 7A.3.1 Load Usage Factors from the Cal-UCONS Commercial Laundry Program ...7-A-4

LIST OF FIGURES

Figure 7A.3.1 Distribution of Load Usage Factors.................................................................7-A-4

7A-1
APPENDIX 7-A. : LOAD USAGE FACTOR IN COMMERCIAL LAUNDRY 

APPLICATIONS 

7A.1 INTRODUCTION

The purpose of this appendix is to clarify how the Department of Energy (DOE) made its 

estimates regarding the load usage factor (LUF) to address potential differences in loading 

practices between residential clothes washer usage and commercial clothes washer usage. 

DOE’s current approach for estimating dryer energy use is based on the existing test procedure 

for residential clothes washers. The approach utilizes the following equation to calculate the percycle energy consumption for removing moisture –

DE = ((LUF ×W )+ (LUFavg ×Wavg )+ (LUF ×W ))×(RMC 4%)× DEF × DUF _

max max min min

Where:

LUF = load usage factor, 

W = weight of test load [pounds (lb)/cycle],

RMC = moisture content that remains after washing (lb),

DEF = nominal energy required for a clothes dryer to remove moisture from clothes 

(0.5kWh/lb), and

DUF = dryer usage factor, a percentage of washer loads dried in a clothes dryer (0.91).

DOE implements the Load Usage Factor, as described in the current test procedure. As per this 

description, LUFmax, LUFmin, and LUFavg are established as described below: 

Table 7A.1.1 Load Usage Factors from the Test Procedure

LUFmax LUFavg LUFmin

Manual Fill 0.72 - 0.28

Adaptive Fill 0.12 0.74 0.14

Since the test procedure describes the load usage for a typical residential application, DOE 

analyzed data from available studies to establish loading practices in a commercial setting. 

7A.2 METHODOLOGY AND DATA

For the purposes of understanding loading patterns, DOE looked at total water consumption as a 

proxy for loading. DOE collected data from the Cal-UCONS Commercial Laundry Program, 

which monitored clothes washers from different coin-operated laundromats or multifamily 

7A-2
laundry rooms within the Southern California Gas Company (SCG) and the San Diego Gas and 

Electric Company (SDG&E) service territories.a The study conducted in situ monitoring of 50 

clothes washers at selected properties, either common area laundry in multi-family buildings or 

coin-operated laundromats. The CCW units included 21 clothes washers located at two 

commercial coin-operated laundromats and 32 clothes washers at four multi-family properties, 

for a total of 53 clothes washers. Of these, only 6 coin-operated laundromats monitored water 

usage. The monitored data included hot and cold water gallons dispersed at 5 minute intervals 

with indicators of a completion of a cycle. In order to assess loading, DOE only examined those 

washers that had gallons recorded for both cold and hot water. For all sites, only six clothes 

washers had data for gallons of hot and cold water. Two of these clothes washers were from the 

same site (CCW#3 and CCW#4). Table 7A.2.1 provides the number of days of data for each 

clothes washer. 

Table 7A.2.1 Cal UCONS Commercial Laundry Program: Number of monitored days 

for each washer

. 

CCW #1 CCW #2 CCW#3 CCW#4 CCW#5 CCW#6

9 13 12 12 35 35

Computation of gallons per cycle

The start of a cycle was denoted if the previous 5 minute data point had 0 gallons of water or if 

the previous 5 minute data point was flagged by the completion of a cycle indicator. After the 

start of a cycle was noted, the gallons of water were then summed until a 5 minute data point was 

flagged as completion of a cycle. 

We further categorized each cycle into different buckets based on their total gallons used during 

that cycle. The Load Usage Factor is described in the current test procedure. 

7A.3 FINDINGS

Table 7.A.3.1 shows the different Load Usage Factors for the six different clothes washers we 

analyzed from the Cal-UCONS Commercial Laundry Program. These are compared to the Load 

Usage Factors from DOE’s test procedure. The distribution of LUFmin varies from 7% to 36% 

across all six clothes washers. A wide range of values is also apparent for LUFavg and LUFmax. 

Figure 7A.3.1 shows the distribution for all clothes washers as well. CCW#1, CCW#5, and 

CCW#6 are all located in multifamily homes. All other clothes washers are located in coinoperated Laundromats. Variability may also be due to different clothes washing behaviors of 

residents living multifamily buildings or customers washing at coin-operated Laundromats. 

However, we do not have enough data here to conclude this. Thus the variability of the data is 

problematic. 

a PNNL 2008. Cal-UCONS Commercial Laundry Program Measurement and Evaluation - PNWD-3910.

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In addition, CCW#5 and CCW#6 are monitored for at least 20 more days than the rest of the 

clothes washers. This may explain why they have a couple of washing cycles with a high water 

usage, but the majority of their washing loads are around the average amount of water per cycle. 

Furthermore, all of these clothes washers are located in the Southern California area, which may 

not be representative of the U.S. population. However, since analysis of the Cal-UCONS 

Commercial Laundry Program does represent a section of the U.S population, DOE considers it 

for a sensitivity analysis. For default LUF values, DOE has decided to use the load usage factors 

from the current test procedure.

Table 7A.3.1 Load Usage Factors from the Cal-UCONS Commercial Laundry 

Program

DOE TP CCW 

#1

CCW 

#2

CCW 

#3

CCW 

#4

CCW 

#5

CCW 

#6

Average 

across 

CCWs

LUFmin 0.14 0.10 0.26 0.14 0.07 0.36 0.29 0.20

LUFavg 0.74 0.69 0.53 0.43 0.37 0.60 0.61 0.54

LUFmax 0.12 0.22 0.21 0.43 0.56 0.04 0.10 0.26

Figure 7A.3.1 Distribution of Load Usage Factors

0%

10%

20%

30%

40%

50%

60%

70%

80%

LUFmin LUFavg LUFmax

Frequency

DOE TP CCW #1 CCW #2 CCW #3 CCW #4 CCW #5 CCW #6

7A-4