CHAPTER 5. ENGINEERING ANALYSIS 

TABLE OF CONTENTS 

5.1 INTRODUCTION ........................................................................................................... 5-1 

5.2 TECHNOLOGIES UNABLE TO BE INCLUDED IN THE ANOPR ANALYSIS....... 5-1 

5.3 PRODUCT CLASSES ANALYZED .............................................................................. 5-5 

5.4 EFFICIENCY LEVELS................................................................................................... 5-8 

5.4.1 Baseline Units .................................................................................................................. 5-8 

5.4.2 Incremental Efficiency Levels ....................................................................................... 5-10 

5.5 METHODOLOGY OVERVIEW .................................................................................. 5-15 

5.5.1 AHAM Data Request..................................................................................................... 5-16 

5.5.2 Manufacturer Interviews ................................................................................................ 5-16 

5.5.3 Product Teardowns ........................................................................................................ 5-17 

5.5.3.1 Generation of Bill of Materials .................................................................... 5-18 

5.5.3.2 Cost Structure of the Spreadsheet Models ................................................... 5-18 

5.5.4 Review of Previous Technical Support Documents ...................................................... 5-20 

5.5.5 Product Testing .............................................................................................................. 5-20 

5.6 ANALYSIS AND RESULTS........................................................................................ 5-20 

5.6.1 Dishwashers ................................................................................................................... 5-20 

5.6.1.1 AHAM Data................................................................................................. 5-20 

5.6.1.2 Product Testing ............................................................................................ 5-23 

5.6.1.3 Product Teardown ........................................................................................ 5-30 

5.6.1.4 Manufacturer Interviews .............................................................................. 5-38 

5.6.2 Dehumidifiers ................................................................................................................ 5-41 

5.6.2.1 AHAM Data................................................................................................. 5-41 

5.6.2.2 Manufacturer Interviews .............................................................................. 5-46 

5.6.2.3 Product Teardowns ...................................................................................... 5-47 

5.6.3 Cooking Products........................................................................................................... 5-57 

5.6.3.1 AHAM Data................................................................................................. 5-57 

5.6.3.2 Review of Past TSDs ................................................................................... 5-63 

5.6.4 Commercial Clothes Washers........................................................................................ 5-70 

5.6.4.1 AHAM Data................................................................................................. 5-70 

5.6.4.2 Manufacturer Interviews .............................................................................. 5-72 

5.6.4.3 Review of the Most Recent TSD for Residential Clothes Washers............. 5-79 

LIST OF TABLES 

Table 5.4.1 EPACT 2005 Standards for Residential Dehumidifiers ...................................... 5-9 

Table 5.4.2 1996 TSD Baseline Energy Factors for Cooking Products ................................. 5-9 

Table 5.4.3 Efficiency Levels for Residential Dishwashers ................................................. 5-11 

Table 5.4.4 Efficiency Levels for Residential Dehumidifiers .............................................. 5-12 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.4.5 Efficiency Levels for Residential Gas Cooktops ............................................... 5-12 

Table 5.4.6 Efficiency Levels for Residential Electric Cooktops......................................... 5-13 

Table 5.4.7 Efficiency Levels for Residential Gas Ovens .................................................... 5-14 

Table 5.4.8 Efficiency Levels for Residential Electric Ovens .............................................. 5-14 

Table 5.4.9 Efficiency Levels for Residential Microwave Ovens ........................................ 5-15 

Table 5.4.10 Efficiency Levels for Commercial Clothes Washers......................................... 5-15 

Table 5.5.1 Engineering Analysis Methods .......................................................................... 5-16 

Table 5.5.2 Major Manufacturing Processes ........................................................................ 5-19 

Table 5.6.1 AHAM Dishwasher Market Share Data Submittal............................................ 5-21 

Table 5.6.2 AHAM Dishwasher Shipments and Shipment-Weighted Efficiency Data 

Submittal ............................................................................................................ 5-21 

Table 5.6.3 AHAM Dishwasher Incremental Cost Data Submittal...................................... 5-22 

Table 5.6.4 Dishwasher Test Unit Features .......................................................................... 5-23 

Table 5.6.5 Comparison of Dishwasher Incremental Efficiency Levels and Teardown 

Unit EFs ............................................................................................................. 5-31 

Table 5.6.6 Design Options on Dishwasher Teardown Units............................................... 5-33 

Table 5.6.7 Incremental Manufacturing Costs for Residential Standard Dishwashers ........ 5-38 

Table 5.6.8 AHAM Dehumidifier Shipments Data Submittal.............................................. 5-42 

Table 5.6.9 AHAM Dehumidifier Shipment-Weighted Efficiency Data Submittal............. 5-42 

Table 5.6.10 AHAM Dehumidifier Market Share Data Submittal for 35.01 to 45.00 

Pints/Day............................................................................................................ 5-42 

Table 5.6.11 AHAM Dehumidifier Market Share Data Submittal for 54.01 to 74.99 

Pints/Day............................................................................................................ 5-43 

Table 5.6.12 AHAM Dehumidifier Incremental Cost Data Submittal for 0–35.00 

Pints/Day............................................................................................................ 5-44 

Table 5.6.13 AHAM Dehumidifier Incremental Cost Data Submittal for 35.01–45.00 

Pints/Day............................................................................................................ 5-44 

Table 5.6.14 AHAM Dehumidifier Incremental Cost Data Submittal for 54.01–74.99 

Pints/Day............................................................................................................ 5-45 

Table 5.6.15 Retained Design Options for Dehumidifiers...................................................... 5-50 

Table 5.6.16 Assumed Dehumidifier Product-Class-Specific Cost and Efficiency 

Parameters.......................................................................................................... 5-51 

Table 5.6.17 Estimated Dehumidifier Cost and Efficiency Parameters for All Product 

Classes................................................................................................................ 5-52 

Table 5.6.18 Incremental Costs to Increase Dehumidifier EF................................................ 5-57 

Table 5.6.19 Microwave Oven Standby Power Comparison.................................................. 5-62 

Table 5.6.20 Gas Cooktop Manufacturing Cost and Efficiency Increments .......................... 5-64 

Table 5.6.21 Electric Coil Cooktop Manufacturing Cost and Efficiency Increments ............ 5-65 

Table 5.6.22 Electric Smooth Cooktop Manufacturing Cost and Efficiency Increments....... 5-65 

Table 5.6.23 Gas Standard Oven Manufacturing Cost and Efficiency Increments ................ 5-66 

Table 5.6.24 Gas Self-Cleaning Oven Manufacturing Cost and Efficiency Increments ........ 5-67 

Table 5.6.25 Electric Standard Oven Manufacturing Cost and Efficiency Increments .......... 5-68 

Table 5.6.26 Electric Self-Cleaning Oven Manufacturing Cost and Efficiency 

Increments.......................................................................................................... 5-68 

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Table 5.6.27 Slopes and Intercepts for Oven Energy Factor versus Cavity Volume 

Relationship ....................................................................................................... 5-69 

Table 5.6.28 Microwave Oven Manufacturing Cost and Efficiency Increments ................... 5-70 

Table 5.6.29 AHAM Commercial Clothes Washer Shipments and Shipment-Weighted 

MEF and WF Data Submittal ............................................................................ 5-70 

Table 5.6.30 AHAM Baseline MEF Commercial Clothes Washer Average Energy and 

Water Use Data Submittal ................................................................................. 5-71 

Table 5.6.31 AHAM Commercial Clothes Washer Incremental Cost Data Submittal........... 5-71 

Table 5.6.32 1996 AHAM Residential Clothes Washer Cost Data Submittal ....................... 5-81 

Table 5.6.33 1996 AHAM Residential Clothes Washer Energy and Water Use Data 

Submittal ............................................................................................................ 5-84 

Table 5.6.34 Incremental Manufacturing Cost for Commercial Clothes Washers................. 5-94 

LIST OF FIGURES 

Figure 5.5.1 Manufacturing Cost Assessment Stages ............................................................ 5-19 

Figure 5.6.1 AHAM Dishwasher Cost-Efficiency Curve ...................................................... 5-22 

Figure 5.6.2 Overall Dishwasher Cycle Parameters versus EF.............................................. 5-26 

Figure 5.6.3 Dishwasher EAEU versus EF ............................................................................ 5-27 

Figure 5.6.4 Dishwasher Machine Electrical Energy Consumption Disaggregated by 

Component ......................................................................................................... 5-28 

Figure 5.6.5 Dishwasher Water Consumption Disaggregated by Cycle Segment ................. 5-29 

Figure 5.6.6 Dishwasher Full Production Cost Distributions ................................................ 5-31 

Figure 5.6.7 Dishwasher Material Cost Distributions............................................................ 5-32 

Figure 5.6.8 Comparison of Dishwasher Incremental Costs for the Efficiency Levels in 

AHAM’s Submittal, 0.58 EF Baseline .............................................................. 5-37 

Figure 5.6.9 Comparison of Dishwasher Incremental Costs for EF = 0.58 to 1.11 ............... 5-37 

Figure 5.6.10 AHAM Dehumidifier Cost-Efficiency Curves .................................................. 5-45 

Figure 5.6.11 Efficiency Range of Dehumidifier Teardowns .................................................. 5-48 

Figure 5.6.12 Baseline Dehumidifier Material Cost Distribution ............................................ 5-49 

Figure 5.6.13 Baseline Dehumidifier Full Production Cost Distribution................................. 5-49 

Figure 5.6.14 Comparison of Dehumidifier Incremental Production Costs: 0-35.00 

Pints/Day............................................................................................................ 5-53 

Figure 5.6.15 Comparison of Incremental Dehumidifier Production Costs: 35.01-45.00 

Pints/Day............................................................................................................ 5-54 

Figure 5.6.16 Comparison of Incremental Dehumidifier Production Costs: 54.01-74.99 

Pints/Day............................................................................................................ 5-54 

Figure 5.6.17 Comparison of Total Incremental Dehumidifier Costs: 0-35.00 Pints/Day ...... 5-55 

Figure 5.6.18 Comparison of Total Incremental Dehumidifier Costs: 35.01-45.00 

Pints/Day............................................................................................................ 5-55 

Figure 5.6.19 Comparison of Total Incremental Dehumidifier Costs: 54.01-74.99 

Pints/Day............................................................................................................ 5-56 

Figure 5.6.20 AHAM Microwave Oven Efficiency versus Rated Output Power .................... 5-60 

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EE-2006-STD-0127 COMMENT 39.2
Figure 5.6.21 AHAM Microwave Oven Efficiency versus Oven Volume .............................. 5-61 

Figure 5.6.22 AHAM Microwave Oven Standby Power Consumption................................... 5-62 

Figure 5.6.23 AHAM Commercial Clothes Washer Incremental Cost Data Submittal........... 5-72 

Figure 5.6.24 2000 Low-Volume versus High-Volume Clothes Washer Cost 

Disadvantage...................................................................................................... 5-88 

Figure 5.6.25 2000 Cost Disadvantage of Producing 100,000 versus 1.5MM Clothes 

Washers per Year with Green Field Facility...................................................... 5-89 

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EE-2006-STD-0127 COMMENT 39.2
CHAPTER 5. ENGINEERING ANALYSIS 

5.1 INTRODUCTION 

After conducting the screening analysis, the Department of Energy (DOE) performed an 

engineering analysis based on the remaining design options. The engineering analysis consists 

of estimating the energy and water consumption and costs of products at various levels of 

increased efficiency. This section provides an overview of the engineering analysis (section 5.1), 

considers technologies which are unable to analyzed for this rulemaking (section 5.2), discusses 

proposed product classes (section 5.35.2), establishes baseline unit specification (section 5.4.1), 

discusses incremental efficiency levels (section 5.4.2), explains the methodology used during 

data gathering (5.5) and discusses the analysis and results (section 5.6) DOE completed a 

separate engineering analysis for residential dishwashers, dehumidifiers, and cooking products 

and commercial clothes washers. 

The primary inputs to the engineering analysis are baseline information from the market 

and technology assessment (Chapter 3 of the TSD) and technology options from the screening 

analysis (Chapter 4). Additional inputs include cost and energy efficiency data, which DOE 

received from the Association of Home Appliance Manufacturers (AHAM) and qualified and 

supplemented through tear-down analysis and manufacturer interviews. The primary output of 

the engineering analysis is a set of cost-efficiency curves. In the subsequent markups analysis 

(Chapter 7), DOE determined customer (i.e. product purchaser) prices by applying distribution 

markups, sales tax and contractor markups. After applying these markups, they serve as the 

input to the building energy-use and end-use load characterization (Chapter 6) and the life-cycle 

cost (LCC) and payback period analyses (Chapter 8). 

DOE typically structures its engineering analysis around one of three methodologies. 

These are: (1) the design-option approach, which calculates the incremental costs of adding 

specific design options to a baseline model; (2) the efficiency-level approach, which calculates 

the relative costs of achieving increases in energy efficiency levels, without regard to the 

particular design options used to achieve such increases; and/or (3) the reverse engineering or 

cost-assessment approach, which involves a “bottom-up” manufacturing cost assessment based 

on a detailed bill of materials derived from teardowns of the product being analyzed. Deciding 

which methodology to use for the engineering analysis depends on the product, the design 

options under study, and any historical data that DOE can draw on. 

5.2 TECHNOLOGIES UNABLE TO BE INCLUDED IN THE ANOPR ANALYSIS 

In performing the engineering analysis, DOE did not consider for analysis certain 

technologies that met the screening criteria but were unable to be evaluated for one or more of 

the following reasons: (1) data are not available to evaluate consumer usage of a product 

incorporating the technology, and, therefore the test procedure conditions and methods may not 

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EE-2006-STD-0127 COMMENT 39.2
be applicable; (2) data are not available to evaluate the energy efficiency characteristics of the 

technology; and (3) available data suggest that the efficiency benefits of the technology are 

negligible. In the first two cases, DOE is unable to adequately assess how these technologies 

impact annual energy consumption 

For technologies that lack consumer usage details (including operating conditions, 

duration, and frequency), DOE believes that the existing test procedures may specify conditions 

and methods that are not representative of actual usage. DOE further believes that even if data 

were available to amend the test procedure, such changes could be extensive enough to require 

total revision, which in turn could warrant the creation of a separate product class for that 

technology in the event that the test procedure changes indicated unique utility. 

Furthermore, certain technologies cannot be measured according to the conditions and 

methods specified in the existing test procedure. 

In other cases, available data suggested that some of the design options resulted in such 

small energy savings as to be negligible. Because DOE intends to focus on the technologies with 

measurable impact on efficiency, design options with negligible energy savings have been 

eliminated from further consideration. 

Dehumidifiers 

Many dehumidifiers feature a built-in relative humidity (RH) sensor, or hygrometer, and 

most (including all units upon which DOE conducted reverse-engineering) feature a built-in 

humidistat, a device that allows the consumer to set the desired RH level for the room. When the 

humidity near the dehumidifier drops below the user-defined or pre-set value, the dehumidifier 

automatically shuts off. This sensor-controlled system presumably saves energy by avoiding 

running the dehumidifier when the RH is such that further dehumidification would be neither 

effective nor desirable. However, there is no industry consensus on patterns in ambient 

conditions and usage. If such parameters were known to DOE, the test procedure, which 

currently specifies constant ambient temperature and humidity, would need to be revised to 

measure energy savings associated with these technologies. Therefore, the built-in 

hygrometer/humidistat design option was not considered for further analysis. 

In addition, several other design options were excluded from consideration in the 

ANOPR based on lack of information on representative consumer usage These include 

improved dehumidifier controls, which incorporate sensors and algorithms to optimize response 

under off-design ambient conditions, and improved flow-control devices. 

Defrost measures are required when air entering a dehumidifier is below 65 degrees 

Fahrenheit (°F), such as in a basement application. Since the test procedure conditions are above 

65° F, no energy savings can be quantified for either improved defrost methods or improved 

demand-defrost controls. Thus, DOE dropped these design options from further analysis for the 

ANOPR. 

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Some dehumidifiers with electronic controls consume standby power when the 

dehumidifier is not performing its intended function. Without industry consensus on usage 

patterns, however, DOE’s test procedure does not include measurement of any standby power 

consumption for dehumidifiers. If such parameters were known to DOE, the test procedure 

would need to be revised to measure energy savings of low-standby-loss controls. Based on the 

lack of information on representative consumer usage, DOE removed the low-standby-loss 

control design option from further consideration for the ANOPR. 

To prevent air filters from clogging, some dehumidifier manufacturers design air filters to 

be removable and washable. Washing the air filter prevents clogging. However, DOE assumes 

rating testing is performed on new machines with little to no dust buildup. In addition, the DOE 

test procedure specifies six hours of continuous testing without any interruptions. Thus, a filter 

could not be removed for cleaning. As a result of the assumed unit cleanliness and continuous 

testing, DOE has no data to determine efficiency improvements associated with washable air 

filters and therefore will not analyze this design option for the ANOPR. 

Cooking Products 

Several technologies are available for cooktops which allow the burners or heating 

elements to automatically adjust in response to cooking-state setpoints, such as cooking vessel 

temperature. These include thermostatically-controlled gas cooktop burners as well as electronic 

controls for electric cooktops. However, DOE is unaware of any data to quantify the energy 

efficiency effects of such technologies. Further, efficiency benefits of these design options are 

only realized under variable burner or element conditions. Because the cooktop test procedure 

does not account for consumer usage patterns, the energy savings of these technologies cannot be 

adequately measured. Therefore, DOE will not consider these design options for further analysis 

for the ANOPR. 

Similarly, DOE is unaware of any data that indicates a measurable energy efficiency 

impact of insulation in gas and electric coil cooktops, so DOE will not analyze this design option 

in the ANOPR for these product classes. 

Induction cooktops require ferromagnetic cookware in order to transfer energy to the 

food contents. While the test block specified in the DOE test procedure is aluminum and thus is 

unable to measure the efficiency of induction cooktops, the National Bureau of Standards (NBS), 

now called National Institute of Standards and Technology (NIST), proposed an alternate 

method of measuring the energy consumption of such cooktops by simply attaching a 

ferromagnetic material to the bottom of the test block. Data obtained by this method suggested 

an efficiency improvement over baseline electric smooth cooktops. However, this test method 

has not been rigorously validated for incorporation into the DOE test procedure and therefore, 

due to the unresolved nature of the NIST data, DOE will eliminate induction elements for 

electric smooth cooktops from further consideration in the ANOPR. 

Some electric cooktops and microwave ovens with electronic controls consume standby 

power, but the EF metrics do not incorporate such power in their calculation. Even though DOE 

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EE-2006-STD-0127 COMMENT 39.2
considers the consumer usage of these products to be well-defined, the current test procedure 

does not measure standby power, thus DOE is unable to quantify the impact on energy savings of 

low-standby-loss electronic controls for these products and will not consider these design options 

during the ANOPR analysis. 

The only currently available gas ovens that DOE is aware of that incorporate radiant 

burners do so for broiling cooking functions, which are a secondary cooking function that is not 

the focus of the DOE efficiency measurement. Energy efficiency is instead measured during the 

primary bake function, thus the energy benefits are not captured by the test procedure under 

these conditions. Accordingly, DOE will eliminate radiant burners in gas ovens from further 

analysis for the ANOPR. 

While there are several residential steam ovens currently on the market, DOE believes 

that the existing test procedure may specify conditions and methods that are not representative of 

actual usage. DOE further believes that even if data were available to amend the test procedure, 

such changes could be extensive enough to require total revision, which in turn could warrant the 

creation of a separate product class in the event that the test procedure changes indicated unique 

utility. Thus, DOE will not consider steam cooking in the ANOPR analysis. 

For added insulation in microwave ovens, this technology will not improve EF, since 

during the short duration of the DOE test procedure as well as during typical usage, the 

microwave oven cavity walls do not heat up. Thus, the energy savings of this design option 

would be so small as to be not be measurable. 

Cooking sensors, which terminate the operation of a microwave oven based upon inferred 

cooking state, appear to promote shorter cook times and thus lower energy consumption. Due to 

the lack of consumer usage details, including operating conditions, duration, and frequency, 

DOE believes that the existing test procedure may specify conditions and methods that are not 

representative of actual usage. Thus DOE will not consider this design option for further 

analysis for the ANOPR. 

According to AHAM, dual magnetrons in microwave ovens do not improve energy 

efficiency due to the added losses associated with two magnetron heaters. In addition, AHAM 

stated that the additional cost of dual magnetrons could not be economically justified. DOE does 

not have any efficiency data on dual magnetrons by which to evaluate this design option. 

Therefore, it will not consider dual magnetrons for further analysis in the ANOPR. 

AHAM stated that virtually no residential solo-function microwave oven still uses a 

ceramic stirrer. Almost all microwave ovens use polypropylene or mica film stirrers, which have 

lower losses than ceramic stirrers. According to AHAM, this design option has already been 

optimized so there is no opportunity for efficiency improvements. The stirrer cover, however, 

may be made of ceramic when there are browning elements that generate too much heat for a 

plastic cover. These covers absorb some microwave energy but are needed to prevent food 

splatter inside the wave guide. Eliminating the ceramic cover would adversely affect consumer 

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EE-2006-STD-0127 COMMENT 39.2
utility by requiring cleaning of the stirrer or by reducing the life of the stirrer. Therefore, DOE’s 

ANOPR analysis will not consider eliminating or improving the ceramic stirrer cover. 

According to AHAM, losses associated with the wave guide are typically less than 0.5 

percent of the overall energy consumption. DOE is not aware of any data demonstrating 

efficiency improvements associated with wave guide improvement, so it will not analyze this 

design option for the ANOPR. 

Commercial Clothes Washers 

Although several manufacturers have made claims regarding improved wash 

performance and greater utility of improved drum designs for horizontal-axis clothes washers, 

DOE is unaware of any publicly-available data to corroborate a decrease in cycle time or water 

consumption or an increase in MEF as a result of implementing this design option. Therefore, 

DOE will not analyze this design option for the ANOPR. 

Even though DOE considers consumer usage of CCWs to be well defined, the current 

tests procedures do not measure standby power. Also, DOE is unaware of any data 

demonstrating energy savings associated with low-standby power supplies for CCWs. Thus, in 

the context of the present rulemaking, DOE eliminated the low-standby-power design option 

from the ANOPR analysis. 

5.3 PRODUCT CLASSES ANALYZED 

DOE separated residential dishwashers, dehumidifiers, and cooking products and 

commercial clothes washers into product classes. Because DOE formulated a separate energy 

conservation standard for each product class, the criteria for separation into different classes are: 

(1) type of energy used (natural gas or electricity), and (2) capacity or other performance-related 

features such as those that provide utility to the consumer, or others deemed appropriate by the 

Secretary that would justify the establishment of a separate energy conservation standard. (42 

U.S.C. 6295 (q) and 6316(a)) 

For dishwashers, the size of the unit significantly impacts the energy consumed. In other 

words, standard-sized dishwashers with relatively greater water consumption have significantly 

greater energy use than compact units. Because standard dishwashers offer enhanced consumer 

utility over compact units (i.e., the ability to wash more dishes), DOE analyzed the following 

product classes, based on the size of the dishwasher (as specified in American National 

Standards Institute (ANSI)/AHAM Standard DW-1-2005, Dishwashers): 

 Compact, capacity less than 8 place settings plus 6 serving pieces; and 

 Standard, capacity equal to or greater than 8 place settings plus 6 serving pieces. 

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EE-2006-STD-0127 COMMENT 39.2
For dehumidifiers, the Energy Policy Act of 2005, Public Law 109-58, (EPACT 2005) 

sets energy conservation standards based on the capacity of the unit as measured in pints of water 

extracted per day. (EPACT 2005, section 135(c), 42 U.S.C. 6295(cc)) DOE believes that there 

are unique design constraints associated with a unit’s capacity that warrant the creation of these 

separate classes. The pints of water extracted per day are measured using the test procedure 

outlined in ANSI/AHAM Standard DH-1-2003, Dehumidifiers. For standards effective October 

1, 2007, EPACT 2005, in section 135(c), names 5 product classes. EPACT 2005 also prescribes 

a new set of amended standards for dehumidifiers in the event that DOE fails to publish a final 

rule requiring new standards to take effect by October 1, 2012. In providing a new set of 

standards, EPACT 2005, in section 135(c), subdivides the 35.01-54.00 pints/day product class 

into 2 product classes: 35.01-45.00 pints/day and 45.01-54.00 pints/day. The 2012 product 

classes are shown below. 

 25.00 pints/day or less; 

 25.01–35.00 pints/day; 

 35.01–45.00 pints/day; 

 45.01–54.00 pints/day; 

 54.01–74.99 pints/day; and 

 75.00 pints/day or more. 

For cooking products, DOE analyzed product classes based on the energy source (i.e., 

gas or electric) and the cooking method (i.e. cooktops, ovens, and microwave ovens). These 

distinctions yielded 5 cooking product classes: gas cooktops, electric cooktops, gas ovens, 

electric ovens, and microwave ovens. DOE’s product classes are based on the list of product 

classes defined by DOE in its 1996 Technical Support Document for Residential Cooking 

Products (1996 TSD), which was released as part of the previous standards rulemaking.1 Gas 

and electric rangesa

 are not listed below as product classes. Because ranges consist of both a 

cooktop and oven, any potential cooktop and oven standards will apply to the individual 

components of the range. As a result, product classes for ranges are not necessary. 

For gas cooktops, DOE’s analyzed product class is: 

 Conventional burners. 

For electric cooktops, DOE’s 1996 TSD determined that the ease of cleaning smooth 

elements provides enhanced consumer utility over coil elements. Because smooth elements 

typically use more energy than coil elements, DOE analyzed the following product classes for 

electric cooktops: 

 Low or high wattage open (coil) elements; and 

 Smooth elements. 

a

 DOE defines a “conventional range” under EPCA as “a class of kitchen ranges and ovens which is a household 

cooking appliance consisting of a conventional cooking top and one or more conventional ovens.” (10 CFR 430.2) 

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EE-2006-STD-0127 COMMENT 39.2
For electric ovens, the 1996 TSD determined that the type of oven-cleaning system is a 

utility feature that affects performance. DOE found that standard ovens and ovens using a 

catalytic continuous-cleaning process use roughly the same amount of energy. Self-cleaning 

ovens use a pyrolytic process that provides enhanced consumer utility with lower overall energy 

consumption as compared to either standard or catalytically-lined ovens. Thus, DOE analyzed 

the following product classes for electric ovens: 

 Standard oven with or without a catalytic line; and 

 Self-cleaning oven. 

For gas ovens, DOE analyzed the following product classes based upon the same 

reasoning as electric ovens: 

 Standard oven with or without a catalytic line; and 

 Self-cleaning oven. 

For microwave ovens, DOE analyzed no further class breakdown. This product class 

can encompass microwave ovens with and without browning elements, but does not include 

microwave ovens that incorporate convection systems (combination ovens). DOE will not 

conduct an analysis at this time of combination microwave ovens due to the inability of the test 

procedure to measure the performance of the convection component and thus a lack of data 

evaluating the energy efficiency or energy efficiency characteristics of microwave ovens 

incoporating convection systems 

For commercial clothes washers, EPCA, as amended by EPACT 2005, applies a single 

standard for energy efficiency and a single standard for water efficiency to all CCWs. (EPACT 

2005, section 136(e); 42 U.S.C. 6313(e)) This class encompasses both top- and front-loading 

units. The statutory provisions do not, however, specifically prevent DOE from creating separate 

product classes subject to the same standards, if such differentiation is deemed appropriate. In 

determining product classes, DOE recognizes there are five classes of residential clothes washer 

classes which are differentiated, in part, by washer axis and that there is certain commonality 

between commercial and residential clothes washers.b

 However, despite the similarities between 

residential and commercial clothes washers, the Congress enacted a single standard for CCWs 

some years after DOE established the five classes for residential clothes washers, which may 

suggest that Congress intended for DOE to retain a single class when updating these standards. 

DOE decided to keep a single product class that encompasses both top-loading and frontloading units for this analysis for several reasons. Also, DOE believes that, even though there 

may be some performance-related features on existing CCWs that might warrant multiple CCW 

b

 DOE understands how some stakeholders could interpret there being only one class of standard-size residential 

clothes washers in DOE’s regulations since the value of the energy efficiency standard is the same for both classes. 

While the standards are the same, DOE notes they are separate in DOE’s regulations found at 430.32(g). The maxtech level for the two classes are different, because of the utility features, and are, therefore, representative of 

separate classes. 

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product classes (as was demonstrated in the residential clothes washer rulemaking), technologies 

may be available that enable top-loading units to attain the same efficiency level as front-loading 

units, thereby rendering any product class distinction meaningless. DOE was sensitive to other 

considerations including the likely outcome of requisite U.S. Department of Justice (DOJ) 

review of the potential impacts, if any, of efficiency standards on competition, given that a large 

percentage of the overall market for commercial washers is produced by one manufacturer that 

specializes in vertical-axis machines. Another consideration may be the potential effect of 

multiple-class standards on the market shares of vertical-axis and horizontal-axis machines. For 

example, if separate standards further widened the first cost differences between these two 

classes of washers, than the overall result might be a decline in the market share of the more 

energy efficient horizontal-axis machines, which could more than offset any energy savings 

achiieved in vertical-axis machines. 

5.4 EFFICIENCY LEVELS 

5.4.1 Baseline Units 

DOE selected baseline units as reference points for each product class, against which 

DOE measured changes resulting from energy conservation standards. The baseline unit in each 

product class represents the basic characteristics of equipment in that class. Typically, a baseline 

unit is a unit that just meets current required energy conservation standards and provides basic 

consumer utility. 

DOE used the baseline units in the engineering analysis and the life-cycle-cost and 

payback-period analysis. To determine energy savings and changes in price, DOE compared 

each higher-energy-efficiency or lower-energy-efficiency design option with the baseline unit. 

The identification of baseline units required establishing the baseline efficiency level. 

EPACT 2005 established standards for dehumidifiers and commercial clothes washers that 

become effective October 1, 2007. For dishwashers, DOE selected baseline efficiency levels 

based upon the current minimum standard. For cooking products, no minimum standards exist, 

so DOE selected baseline levels from the 1996 TSD. For commercial clothes washers, DOE 

used the baseline unit to evaluate new water factor standards in addition to energy conservation 

standards. 

The minimum energy conservation standards for dishwashers, as measured by the 

energy factor (EF) in cycles per kilowatt-hour (kWh), became effective on May 14, 1994. DOE 

developed the following standards for compact and standard capacity dishwashers (10 CFR Part 

430.32(f), Subpart C): 

 Compact = 0.62 EF; and 

 Standard = 0.46 EF. 

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EE-2006-STD-0127 COMMENT 39.2
For dehumidifiers, each energy efficiency level is expressed as a minimum EF, which is 

a function of liters per kWh. EPACT 2005 sets the current minimum energy conservation 

standards for dehumidifiers based on the unit’s capacity (in pints/day). Table 5.4.1 shows the 

product classes established by EPACT 2005, along with the standard levels set to take effect 

October 1, 2007. (EPACT 2005, section 135(c)(4); 42 U.S.C. 6295(cc); 70 FR 60407, 60414, 

(October 18, 2005); 10 CFR 430.32(v)) DOE will use the October 1, 2007 levels as baseline 

efficiency levels. 

Table 5.4.1 EPACT 2005 Standards for Residential Dehumidifiers 

Dehumidifier Capacity Standards Effective October 1, 2007 

EF, liters/kWh 

25.00 pints/day or less 1.00 

25.01–35.00 pints/day 1.20 

35.01–54.00 pints/day 1.30 

54.01–74.99 pints/day 1.50 

75.00 pints/day or more 2.25 

For residential cooking products (except for the prescriptive standard for gas products), 

there are no existing minimum energy conservation standards, as previous analyses failed to 

determine economic justification for them. The DOE test procedure uses an EF to rate the 

efficiency of cooking products. The EF for these products is the ratio of the annual useful 

cooking energy output of the residential cooking appliance (i.e. the energy conveyed to the item 

being heated) to its total annual energy consumption. In accordance with the 1996 TSD on 

residential cooking products, DOE has selected the baseline EFs for the product classes DOE is 

using in this rulemaking listed in Table 5.4.2 

Table 5.4.2 1996 TSD Baseline Energy Factors for Cooking Products 

Product Class Baseline from 1996 TSD 

EF 

Gas Conventional Burner Cooktop 0.156 

Electric Open (Coil) Element Cooktop 0.737 

Electric Smooth Element Cooktop 0.742 

Gas Standard Oven 0.030 

Gas Self-Clean Oven 0.054 

Electric Standard Oven 0.107 

Electric Self-Clean Oven 0.096 

Microwave Oven 0.557 

For all commercial clothes washers, EPCA establishes the following energy and water 

conservation standards: a minimum modified energy factor (MEF) of 1.26 cubic feet (ft3

) per 

kWh and a maximum water factor (WF) of 9.5 gallons per cubic foot. (EPACT 2005, section 

136(e); 42 U.S.C. 6313(e); see also 70 FR 60416 (Oct. 18, 2005), adding 10 CFR 431.156) In 

this rulemaking, DOE is using a baseline model that has those efficiencies. The MEF takes into 

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EE-2006-STD-0127 COMMENT 39.2
consideration not only the energy consumption of the washer but also the amount of energy 

required to dry clothes based on the remaining moisture content of the clothes. 

5.4.2 Incremental Efficiency Levels 

For the majority of the product classes presented in section 5.3, DOE analyzed several 

efficiency levels and obtained incremental cost data at each of these levels. Tables 5.4.3 through 

Table 5.4.10 provide efficiency levels and the reference source of each level for each of the 

products under consideration. DOE notes that in some cases the highest efficiency level was 

identified based on a review of available product literature for products commercially available 

(i.e., commercial clothes washers, dishwashers, and dehumidifiers). For cooking products, the 

maximum levels identified Table 5.4.5 through Table 5.4.9 are based on data developed from the 

design option analysis in the previous rulemaking. 

For residential dishwashers, DOE considered 7 efficiency levels beyond the baseline 

efficiency levels for both standard and compact product classes, as listed in Table 5.4.3. These 

levels were derived from Energy Starc

 criteria, Consortium for Energy Efficiency (CEE) Tier 1 

and 2 levels, and the current maximum technology that is commercially available. DOE also 

added 2 levels to fill the gap between CEE Tier 2 and the current maximum technology that is 

commercially available. As will be discussed in section 5.6.1.1, AHAM provided incremental 

cost data for the first 5 efficiency levels of the standard class only. For compact dishwashers, 

fewer than 3 manufacturers produce products within this product class. Therefore, for disclosure 

purposes, AHAM did not submit data. As a result, DOE conducted an engineering analysis only 

on standard dishwashers DOE achieved scaling for compact dishwashers by using the ratio of 

current standard levels for standard size versus compact size units, although it determined the 

max-tech level by a review of technology in the current Energy Star database of certified 

dishwashers. 

c

 Energy Star is a voluntary labeling program, backed by the U.S. Environmental Protection Agency (EPA) and 

DOE, which identifies energy efficient products through a qualification program. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.4.3 Efficiency Levels for Residential Dishwashers 

Level Efficiency Level Source Efficiency Level (EF), cycles/kWh 

Compact Standard 

baseline Current Federal Standard 0.62 0.46 

1 Energy Star (prior to January 1, 2007) (scaled 

for compact) 0.78 0.58 

2 CEE Tier 1 (2006) (scaled for compact) 0.84 0.62 

3 Energy Star (January 1, 2007) 0.88 0.65 

4 CEE Tier 2 (2006) (scaled for compact) 0.92 0.68 

5 Gap Fill 1.01 0.72 

6 Gap Fill 1.08 0.80 

7 Max Available 1.74 1.11 

AHAM provided incremental cost data for 3 of the 6 dehumidifier product classes. The 

other product classes were not explicitly considered in the engineering analysis and DOE intends 

to extend the results in later analyses to the omitted classes (45.01-54.00 pints/day, 75.00 and 

greater pints/day, and 25.00 pints/day or less). DOE combined two product classes defined by 

EPACT 2005—25.00 pints/day or less and 25.01–35.00 pints/day—to form a single product 

class of 0–35.00 pints/day for this analysis, due to the similar aggregation of data by AHAM in 

its manufacturer cost data submittal. For purposes of conducting the NIA, DOE believes that the 

results from the product classes analyzed can be extended to the two statutorily-set product 

classes for which AHAM data (or comparable data) are unavailable. This approach is believed 

to be valid due to chassis and component similarities among the product classes, with primary 

differences due to scaling. 

To create incremental efficiency levels for residential dehumidifiers shown in Table 

5.4.4, DOE used the default 2012 standards, Energy Star data, and stakeholder input. The first 

efficiency level above the baseline is a gap fill between the baseline and the default efficiency 

level set to become effective October 1, 2012. The second efficiency level is the default 

efficiency level set to become effective October 1, 2012. Dehumidifier manufacturers 

recommended the third and fourth levels. The fifth level is the maximum efficiency level 

available in the Energy Star database of qualified dehumidifiers, as of April 27, 2006. Table 

5.4.4 shows incremental efficiency levels for the product classes for which AHAM submitted 

data. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.4.4 Efficiency Levels for Residential Dehumidifiers 

Dehumidifier Capacity Efficiency Level (EF), liters/kWh 

baseline 1 2 3 4 5** 

0–35.00 pints/day 1.20* 1.25 1.30 1.35 1.40 1.45 

35.01–45.00 pints/day 1.30 1.35 1.40 1.45 1.50 1.74 

54.01–74.99 pints/day 1.50 1.55 1.60 1.65 1.70 1.80 

*Note: baseline efficiency level listed is the baseline level for dehumidifiers rated at 25.01-35.00 Pints/Day 

** Max available 

Table 5.4.5 presents the efficiency levels analyzed for residential gas cooktops. The 

baseline and higher efficiency levels are based on the analysis performed in 1996 for the 

previous rulemaking. Since the 1996 TSD took a design-options approach to the analysis, each 

efficiency level is associated with a particular design option or combination of design options. 

Two higher efficiency levels for gas cooktops were included in the 1996 TSD that are not 

considered here due to the elimination of design options. In the current analysis, reflective 

surfaces are screened out due to impacts on consumer utility, and thermostatically-controlled 

burners were not analyzed for the ANOPR due to the inability of the DOE test procedure to 

adequately represent usage patterns and therefore energy efficiency characteristics. The 

combination of design options that produces the maximum technologically feasible EF is 

designated as “max tech”. 

DOE has structured the analysis for standing pilot igntion systems as a design option 

associated with the baseline configurations because DOE has determined that cooktops 

incorporating such ignition systems do not provide unique utility. Power outages are not 

frequent and long enough for residential electricity customers to consider operation during a lack 

of electric power a significant utility. Between 90 and 93 percent of such customers experience 

no electricity outages longer than four hours per year.2

 The first standards efficiency level 

corresponds to the elimination of standing pilot lights. 

Table 5.4.5 Efficiency Levels for Residential Gas Cooktops 

Level Efficiency Level Source Conventional Burners 

Cooking Efficiency EF 

baseline 1996 TSD Baseline (with standing pilots) 0.399 0.156 

1 1996 TSD (without standing pilots) 0.399 0.399 

2 Max Tech (1996 TSD) 0.420 0.420 

The 1996 TSD analyzed 2 efficiency levels for electric coil cooktops and 3 levels for 

electric smooth cooktops. Since the 1996 TSD took a design-options approach to the analysis, 

each efficiency level is associated with a particular design option or combination of design 

options. In the current analysis, however, reflective surfaces are screened out as a design option 

for electric coil cooktops due to impacts on consumer utility, and induction elements are not 

analyzed for electric smooth cooktops because the available efficiency data, while suggestive of 

energy savings, cannot be validated by the existing DOE test procedure. In addition, radiant 

elements for smooth electric cooktops, which were included in the 1996 TSD, were not 

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EE-2006-STD-0127 COMMENT 39.2
considered as a design option for this rulemaking because manufacturer data provided to DOE 

for the 1996 TSD indicated that this technology does not offer an efficiency improvement over 

the baseline according to the DOE test procedure. Therefore, only a single efficiency level 

beyond the baseline is being analyzed for both electric coil and smooth cooktops, and by default 

this level becomes the max tech, as shown in Table 5.4.6. 

Table 5.4.6 Efficiency Levels for Residential Electric Cooktops 

Level Efficiency Level Source 

Open (Coil) Elements Smooth Elements 

Cooking 

Efficiency EF Cooking Efficiency EF 

baseline 1996 TSD Baseline 0.737 0.737 0.742 0.742 

1 1996 TSD 0.769 (Max Tech) 0.769 0.753 (Max Tech) 0.753 

Efficiency levels for gas ovens, as shown in Table 5.4.7, are based on the 1996 TSD. 

Since the 1996 TSD took a design-options approach to the analysis, each efficiency level is 

associated with a particular design option or combination of design options. The oven separator 

design option from the 1996 TSD was screened out in the current analysis due to consumer 

safety and utility issues, as well as a lack of practicability to design and manufacture. Lowstandby-loss electronic controls were added as design options for both standard and self-cleaning 

gas ovens, but were not included as efficiency levels because DOE does not have efficiency or 

cost increment information on them. 

The baseline efficiency level for gas standard ovens assumes that the product is equipped 

with standing pilot lights, and the first standards efficiency level corresponds to the elimination 

of standing pilot lights based on the same reason as for gas cooktops. However, because the 

cleaning cycle of gas self-clean ovens requires electrical energy use, EPCA in effect requires that 

such ovens currently be equipped with a non-standing pilot ignition system because such an 

ignition system is disallowed if there is an electrical cord provided on the product. Therefore, the 

baseline efficiency level for gas self-cleaning ovens assumes they lack a standing pilot light. 

Further, the first standards efficiency level is not based on elimination of a standing pilot, but 

rather on the addition of the forced convection design option. 

Electronic spark ignition lowers the standby power consumption as well as the cooking 

efficiency of standard gas ovens, and since the standard gas oven EF rating includes standby 

power, results in an overall reduction in energy consumption. Electric spark ignition has the 

same functionality as hot surface ignition sources and is therefore listed as an alternate efficiency 

level to the hot surface (glo-bar) design option. DOE is seeking input on these as design options 

from stakeholders for the Notice of Proposed Rulemaking (NOPR). 

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Table 5.4.7 Efficiency Levels for Residential Gas Ovens 

Level Efficiency Level Source 

Standard Oven Self-Cleaning Oven 

Cooking 

Efficiency EF Cooking Efficiency EF 

baseline 1996 TSD Baseline (with 

standing pilot light) 0.059 0.0298 0.071 0.0540 

1 1996 TSD 0.058 (Glo-bar 

ignition) 0.0536 0.088 0.0625 

2 1996 TSD 0.061 0.0566 0.088 0.0627 

3 1996 TSD 0.062 0.0572 0.089 (Max Tech) 0.0632 

4 1996 TSD 0.065 0.0593 - -

5 1996 TSD 0.065 0.0596 - -

6 1996 TSD/Current 

Analysis 0.066 (Max Tech) 0.0600 - -

1a(1) 1996 TSD (with 

electronic spark ignition) 0.058 0.0583 - -

(1) Note: Standard levels 1 and 1a correspond to designs that are utilized for the same purpose--eliminate the need 

for a standing pilot--but the technologies for each design are different. Standard level 1 is a hot surface ignition 

device while standard level 1a is a spark ignition device 

Efficiency levels for electric ovens, shown in Table 5.4.8, are primarily based on the 

1996 TSD. The oven separator design option from the 1996 TSD was screened out in the current 

analysis due to consumer safety and utility issues, as well as a lack of practicability to design and 

manufacture. The bi-radiant oven was screened out due to a lack of technological feasibility and 

practicability to manufacture, as well as impacts on consumer utility. Low-standby-loss 

electronic controls were added as design options for both standard and self-cleaning electric 

ovens in this analysis, but were not included as efficiency levels because, even though the test 

procedure accounts for the energy consumption of electronic controls, DOE does not have 

incremental efficiency or cost information on them. DOE is seeking input on these from 

stakeholders for the NOPR. 

Table 5.4.8 Efficiency Levels for Residential Electric Ovens 

Level Efficiency Level Source 

Standard Oven Self Cleaning Oven 

Cooking 

Efficiency EF Cooking Efficiency EF 

baseline 1996 TSD Baseline 0.122 0.1066 0.138 0.1099 

1 1996 TSD/Current Analysis 0.128 0.1113 0.138 0.1102 

2 1996 TSD/Current Analysis 0.134 0.1163 0.142 (max-tech) 0.1123 

3 1996 TSD/Current Analysis 0.137 0.1181 - -

4 1996 TSD/Current Analysis 0.140 0.1206 - -

5 1996 TSD/Current Analysis 0.141 (max-tech) 0.1209 - -

For microwave ovens, Table 5.4.9 lists the efficiency levels that were retained from the 

1996 TSD, even though recent AHAM-supplied data suggests slightly different baseline and 

maximum-available efficiencies of a representative sample of current models. For example, the 

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minimum average efficiency among the microwave ovens recently tested by AHAM was 54.8 

percent, while the maximum average efficiency was 61.8 percent, compared to 55.7 percent and 

60.2 percent, respectively, from the 1996 TSD. However, it was noted that the standard 

deviation in efficiency measurements for any given microwave oven ranged from 0.2 to 1.2 

absolute percentage points. Therefore, given this test-to-test variation, it was determined by 

DOE that the efficiency levels from the 1996 TSD were still representative of the state of current 

microwave oven technology to the extent that the DOE test procedure can capture performance. 

Further discussion of the AHAM test data is provided in section 5.6.3.1. 

Table 5.4.9 Efficiency Levels for Residential Microwave Ovens 

Level Efficiency Level Source Efficiency Level (EF) 

baseline 1996 TSD Baseline 0.557 

1 1996 TSD 0.586 

2 1996 TSD 0.588 

3 1996 TSD 0.597 

4 1996 TSD Max Tech 0.602 

EPCA mandates that DOE determine both a minimum MEF and a maximum WF. DOE 

analyzed 6 efficiency levels beyond the baseline for commercial clothes washers, as listed in 

Table 5.4.10. These levels were based on Energy Star, the CEE Commercial Clothes Washer 

Initiative, and maximum levels that are currently commercially available. A gap-fill level was 

added based on stakeholder input. AHAM provided incremental cost data only at 2 of these 

levels (1.42 MEF/9.5 WF and 2.00 MEF/5.5 WF). 

Table 5.4.10 Efficiency Levels for Commercial Clothes Washers 

Level Efficiency Level Source Efficiency Level 

MEF, ft3

/kWh WF, gallons/ft3 

baseline DOE Standard (effective 2007) 1.26 9.5 

1 CEE Tier 1 (January 1, 2004) 1.42 9.5 

2 CEE Tier 2 (January 1, 2004) 1.60 8.5 

3 Energy Star (effective 2007) 1.72 8.0 

4 CEE Tier 3A (January 1, 2004) 1.80 7.5 

5 Gap Fill 2.00 5.5 

6 Max Available 2.20 5.1 

5.5 METHODOLOGY OVERVIEW 

DOE used data submitted by AHAM as the primary source of cost information for the 

engineering analysis. AHAM provided DOE with aggregated incremental manufacturing cost 

data from it member companies. DOE conducted an independent review of the AHAM data 

using several methods and data sources. To gain a better understanding of the data submitted by 

member companies and to be able to relate the costs of improving efficiency to discrete (or 

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EE-2006-STD-0127 COMMENT 39.2
system) technologies, DOE conducted interviews with manufacturers of residential dishwashers 

and dehumidifiers and commercial clothes washers. For dishwashers and dehumidifiers, DOE 

performed detailed product teardowns on several product models spanning a range of efficiencies 

to generate similar cost-efficiency curves for validation of the AHAM data. For products which 

were the subject of a rulemaking in the recent past, DOE reviewed the previous TSDs and 

compared cost and performance information to the AHAM data and other published data. 

Finally, DOE conducted detailed energy performance testing of dishwashers at an independent 

laboratory to gain insights into energy performance and disaggregated energy use of components 

and subsystems. Table 5.5.1 below shows which methods DOE used for each product. 

Table 5.5.1 Engineering Analysis Methods 

Method 

Products 

Dishwashers Dehumidifiers Cooking 

Products 

Commercial 

Clothes Washers 

AHAM Data √ √ √ √

Review of Past TSD √ √

Product Teardown √ √

Product Testing √

Manufacturer 

Interviews √ √ √

5.5.1 AHAM Data Request 

In support of this rulemaking effort, DOE requested incremental cost data from AHAM 

for each of the 4 product categories. The data represent the average incremental production cost 

to improve a baseline unit to a specified efficiency level. This methodology constitutes an 

efficiency-level approach to the engineering analysis because DOE examined aggregated 

incremental increases in manufacturer selling price at specified levels of energy efficiency. In 

addition, DOE requested shipments, shipment-weighted average efficiency, and market share 

efficiency data. Tables of aggregated data provided to DOE by AHAM are contained in 

Appendix 5A. 

5.5.2 Manufacturer Interviews 

AHAM provided to DOE shipment-weighted manufacturer costs. These costs included 

the shipment-weighted average cost as well as the lowest and highest single-manufacturer cost to 

achieve efficiency levels above the baseline level. Presenting the data in this manner enables 

stakeholders to appreciate the variability in baseline units, design strategies, and cost structures 

that exist among manufacturers. To better understand and explain the causes of these cost 

variances, DOE supplemented these cost data with information obtained through follow-up 

manufacturer interviews. These confidential interviews provided a deeper understanding of the 

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EE-2006-STD-0127 COMMENT 39.2
various combinations of technologies used to increase product efficiency, and their associated 

manufacturing costs. 

Sample questions asked during the follow-up interviews are contained in Appendix 5B. 

During the interviews, DOE also gathered information about the capital expenditures 

required to increase the efficiency of the baseline units to various efficiency levels (i.e., 

conversion capital expenditures by efficiency or energy-use level). The interviews provided 

information about the size and the nature of the capital investments. DOE also requested 

information about the depreciation method used to expense the conversion capital. 

5.5.3 Product Teardowns 

Other than obtaining detailed manufacturing costs directly from a manufacturer, the most 

accurate method for determining the production cost of a piece of equipment is to disassemble 

the equipment piece-by-piece and estimate the material and labor cost of each component using a 

process commonly called a physical teardown. A supplementary method, called a catalog 

teardown, uses published manufacturer catalogs and supplementary component data to estimate 

the major physical differences between a piece of equipment that has been physically 

disassembled and another piece of similar equipment. DOE only performed physical teardown 

analysis on dehumidifiers and dishwashers. The teardown methodology is expanded in section 

5.5.3.1 and section 5.5.3.2.

Selection of Units 

During the process of selecting units for teardown, DOE considered 3 main questions: 

 What efficiency levels should be captured in the teardown analysis?

 Are there units on the market that capture all potential efficiency levels and design options?

 Which of the available units are most representative? 

In responding to the preceding questions, DOE adopted the following criteria for 

selecting units for the teardown analysis: 

 The selected products should span the full range of efficiency levels for each product class 

under consideration; 

 Within each product class, if possible, the selected products should come from the same 

manufacturer and be within the same product series; 

 The selected products should primarily come from manufacturers with large market share in 

that product class, although the highest efficiency products were chosen irrespective of 

manufacturer; and 

 The selected products should have non-efficiency-related features that are the same as, or 

similar to, features of other products in the same class and at the same efficiency level. 

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EE-2006-STD-0127 COMMENT 39.2
Additional criteria for selecting the teardown units specific to each product category are 

described in sections 5.6.1.3 for dishwashers and section 5.6.2.3 for dehumidifiers. 

5.5.3.1 Generation of Bill of Materials 

The end result of each teardown is a structured bill of materials (BOM). Structured 

BOMs describe each equipment part and its relationship to the other parts, in the estimated order 

of assembly. The BOMs describe each fabrication and assembly operation in detail, including 

the type of equipment needed (e.g., stamping presses, injection molding machines, spot-welders, 

etc.) and the process cycle times. The result is a thorough and explicit model of the production 

process. 

The BOMs incorporate all materials, components, and fasteners, classified as either raw 

materials or purchased parts and assemblies. The classification into raw materials or purchased 

parts is based on DOE’s previous industry experience, recent information in trade publications, 

and discussions with high- and low-volume original equipment manufacturers (OEMs). 

For purchased parts, the purchase price is an estimate based on volume-variable price 

quotations and detailed discussions with suppliers. For fabricated parts, the price of intermediate 

materials (e.g., tube, sheet metal) and the cost of transforming them into finished parts are an 

estimate based on current industry pricing. 

The cost of raw materials was determined using prices for copper, steel and aluminum 

from the American Metals Market.3

 The prices for rifled and unrifled copper tubing were 

obtained directly from a tubing manufacturer. 

The price of steel drastically increased in 2005, and the price of copper has increased 

steadily since 2004. Because DOE is using a 5-year average in material prices from 2002-2006, 

these price increases are normalized, which better represents long-term material prices. 

5.5.3.2 Cost Structure of the Spreadsheet Models 

The manufacturing cost assessment methodology used is a detailed, component-focused 

technique for rigorously calculating the manufacturing cost of a product (direct materials, direct 

labor and some overhead costs). Figure 5.5.1 shows the 3 major steps in generating the 

manufacturing cost. 

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EE-2006-STD-0127 COMMENT 39.2
Figure 5.5.2 Manufacturing Cost Assessment Stages 

The first step in the manufacturing cost assessment was the creation of a complete and 

structured BOM from the disassembly of the units selected for teardown. The units were 

dismantled, and each part was characterized according to weight, manufacturing processes used, 

dimensions, material, and quantity. The BOM incorporates all materials, components, and 

fasteners with estimates of raw material costs and purchased part costs. Assumptions on the 

sourcing of parts and in-house fabrication were based on industry experience, information in 

trade publications, and discussions with manufacturers. Interviews and plant visits were 

conducted with manufacturers to ensure accuracy on methodology and pricing. 

Following the development of a detailed BOM, the major manufacturing processes were 

identified and developed for the spreadsheet model. These processes are listed in Table 5.5.2. 

Table 5.5.2 Major Manufacturing Processes 

Fabrication Finishing Assembly/Joining Quality Control 

Fixturing Washing Adhesive Bonding Inspecting & Testing 

Stamping/Pressing Powder Coating Spot Welding 

Brake Forming De-burring Seam Welding 

Cutting and Shearing Polishing 

Insulating 

Fabrication process cycle times were estimated and entered into the BOM. For this 

analysis, $24.00 per hour was used as the average fully-burdened labor rate based on typical 

annual wages and benefits of industry employees. In the final step of the cost assessment, 

assembly times and associated direct labor costs were estimated. Once the cost estimate for each 

teardown unit was finalized, a detailed summary was prepared for relevant components, 

subassemblies and processes. The BOM thus details all aspects of unit costs. 

Design options used in units subject to teardown are noted in the summary sheet of each 

cost model and are cost-estimated individually. Thus, various implementations of design options 

can be accommodated, ranging from assemblies that are entirely purchased to units that are made 

entirely from raw materials. Hybrid assemblies, consisting of purchased parts and parts made on 

site are thus also accommodated. 

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5.5.4 Review of Previous Technical Support Documents 

DOE reviewed previous rulemaking TSDs to assess their applicability to the current 

standard setting process for cooking products and commercial clothes washers. These previous 

rulemaking technical support documents served as a source for design options, baseline 

efficiency levels, and energy consumption analysis, in addition to other sources. DOE utilized 

the 1996 cooking products TSD as a source for baseline unit efficiency as well as design options 

and incremental cost and efficiency data. This approach for cooking products was endorsed by 

stakeholders. DOE also reviewed the 2000 residential clothes washer TSD since residential and 

commercial clothes washers share the same design options, are frequently built on the same 

chassis, and are therefore subject to similar economic impacts. 

5.5.5 Product Testing 

DOE conducted product testing on residential dishwashers to develop a better 

understanding of the potential efficiency improvements of design options and to develop 

disaggregated efficiency data. 

5.6 ANALYSIS AND RESULTS 

5.6.1 Dishwashers 

The dishwasher engineering analysis was performed by considering cost and efficiency 

information from multiple sources. AHAM provided incremental manufacturing costs for all but 

the highest efficiency levels of interest to DOE. DOE supplemented these data points by 

conducting its own engineering analysis, comprised of performance testing at an independent 

laboratory and manufacturing cost estimates from detailed teardowns of currently-available 

dishwashers. Manufacturer interviews were also conducted to obtain greater insight into the 

design strategies to improve efficiency and the associated costs. 

5.6.1.1 AHAM Data 

AHAM provided to DOE shipment data from its member companies for dishwashers. 

Table 5.6.1 shows market share by energy factor for residential dishwasher shipments from 2002 

to 2005. 

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Table 5.6.1 AHAM Dishwasher Market Share Data Submittal 

EF Range, cycles/kWh Year 

2002 2003 2004 2005 

0.46-0.49 (Baseline = 0.46) 40% 22% 9% 3% 

0.50-0.53 9% 5% 2% 2% 

0.54-0.57 0% 0% 0% 2% 

0.58-0.59 (2006 Energy Star = 0.58) 15% 19% 18% 43% 

0.60-0.61 13% 16% 28% 17% 

0.62-0.63 4% 23% 31% 22% 

0.64-0.65 (2007 Energy Star = 0.65) 9% 6% 9% 8% 

0.66-0.67 5% 5% 1% 0% 

0.68 and above 5% 5% 2% 3% 

TOTAL: 100% 100% 100% 100% 

On a shipment-weighted basis, the average efficiency of a dishwasher sold in the U.S. has 

been increasing since 1995, according to the AHAM-submitted data shown in Table 5.6.2. 

Table 5.6.2 AHAM Dishwasher Shipments and Shipment-Weighted Efficiency Data 

Submittal 

Year 

Shipments, 

Domestic + Imports 

(# of Units) 

Shipment-Weighted 

Average Efficiency 

(EF, cycles/kWh) 

1995 4,253,745 0.485 

1996 4,316,828 0.476 

1997 4,655,200 0.495 

1998 5,073,023 0.508 

1999 5,424,973 0.504 

2000 5,833,686 0.503 

2001 5,752,217 0.533 

2002 5,906,348 0.553 

2003 6,467,303 0.581 

2004 6,867,551 0.598 

2005 7,280,046 0.599 

AHAM also provided DOE with incremental manufacturing cost data from its member 

companies up to an EF of 0.72. These data include minimum, maximum and average shipmentweighted total incremental costs. These incremental costs include capital costs for tooling and 

equipment, depreciated assuming a 5-year useful life. In addition, AHAM estimated the number 

of dishwashers shipped that would be impacted by standards at each level. 

The data submitted by AHAM represents aggregate input from the producers of 

approximately 90 percent of the standard dishwashers sold in the U.S. Table 5.6.3 shows the 

submitted data. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.6.3 AHAM Dishwasher Incremental Cost Data Submittal 

EF Level (cycles/kWh) 0.58 0.62 0.65 0.68 0.72 

Shipment-Weighted 

Incremental Cost ($) for each 

EF level 

Min. 3.22 4.52 5.39 17.11 34.05 

Avg. 4.01 7.38 14.00 30.35 71.38 

Max. 4.92 8.43 14.50 37.64 91.74 

Avg. One-Time Product 

Conversion Expenses, Million 

$, Total for all Manufacturers 

R&D 1.43 4.43 5.73 18.53 29.23 

Marketing 0.99 1.99 3.29 7.49 13.99 

Conversion Capital 

Expenditure Assumptions, 

Million $, Total for all 

Manufacturers 

Building Insufficient Manufacturer Data Submitted 

Tooling and 

Equipment 16.85 19.95 23.25 44.85 98.45 

Total Shipments, Thousands, subject to 

retooling, conversion, etc. as a function of 

minimum EF level revision 

3,452 7,302 7,302 7,302 7,302 

Incremental Cost ($) 

Note: Shipment-weighted tooling equipment depreciation lifetime is 5 years 

Figure 5.6.1 plots the average incremental cost as a function of EF for the AHAM 

dishwasher data. The lowest point on the graph indicates the baseline level and therefore has a 

cost increment of $0. Note that the curve ‘breaks’ at an EF of 0.65. Above this EF, the cost to 

raise dishwasher efficiency increases dramatically. 

$80

$70

$60

$50

$40

$30

$20

$10

$0

0.72, $71.38 

0.46, $0.00 

0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 

EF 

Figure 5.6.1 AHAM Dishwasher Cost-Efficiency Curve 

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EE-2006-STD-0127 COMMENT 39.2
5.6.1.2 Product Testing 

Dishwasher testing was performed on a group of dishwashers covering a broad range of 

potential standard levels. The test results included submetered component energy consumption 

data which enabled DOE to measure the performance of various design options. The tests also 

served to quantify patterns of water and energy consumption during various stages of the cycle 

and identify energy efficiency and wash performance strategies. Six standard-size dishwashers 

were identified as test units whose EFs spanned a range across two different product platforms 

from the minimum Energy Star level (prior to the increase in January 2007) to the maximum EF 

available. The products chosen comprised multiple units from multiple manufacturers, and were 

selected carefully to identify design options associated with each efficiency level. Beyond 

measurements required to measure the performance according to the DOE test procedure, the 

testing consisted of multi-submetering to record disaggregated energy consumption with various 

design options. Table 5.6.4 lists features of the tested units. 

Table 5.6.4 Dishwasher Test Unit Features 

Feature Dishwasher Test Unit Designation 

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

Rated EF 

(cycle/kWh) 0.58 0.64 0.68 0.78 0.93 1.11 

Controls Electronic ElectroMechanical Electronic Electronic Electronic Electronic 

Soil Sensing No No Yes No Yes Yes 

Tub Material Plastic Plastic Plastic Stainless Stainless Stainless 

Main Pump 

Speeds 1 1 3 1 1, Triac control 

1, Triac 

control 

Spray System 2 arms, 1 

nozzle 

2 arms, 1 

nozzle 3 arms 2 arms 2 arms 

2 main arms, 

1 cutlery tray 

sprayer 

Spray Arm 

Diverter Yes Yes Yes No Yes Yes 

Valve 

Water Heater 

Type Tubular Tubular Tubular FlowThrough 

FlowThrough FlowThrough 

Temperature 

Sensor Fixed Fixed Thermocouple 

Thermocouple Thermocouple Thermocouple 

Venting 

System None None Active 

Door Vent None Fan-Assist 

Vent 

Fan-Assist 

Vent 

Each dishwasher was tested at an independent laboratory according to the DOE test 

procedure (10 CFR 430 Subpart B, Appendix C). The test procedure consists of setting nominal 

ambient and inlet water conditions, selecting a “normal cycle”, and running the dishwasher with 

the appropriate test load. “Normal” conditions are defined in the test procedure as the cycle type 

recommended by the manufacturer for completely washing a full load of normally-soiled dishes 

5-23 

EE-2006-STD-0127 COMMENT 39.2
including the power-dry feature. DOE determined that none of the dishwashers tested had a 

truncated normal cycle, defined as a normal cycle that is interrupted to eliminate the power-dry 

feature after the termination of the last rinse operation. For dishwashers that are not equipped 

with a soil sensor, the test load consists of 8 clean place settings plus 6 serving pieces, and the 

unit is run for a single cycle. For soil-sensing dishwashers, the unit is tested at sensor heavy 

response, sensor medium response, and sensor light response, as defined by the following test 

loads: 

 Sensor Heavy Response – the dishwasher is loaded with 8 place settings plus 6 serving 

pieces. Four of the 8 place settings are soiled according to ANSI/AHAM DW-1-2005. 

 Sensor Medium Response – the dishwasher is loaded with 8 place settings plus 6 serving 

pieces. Two of the 8 place settings are soiled according to ANSI/AHAM DW-1-2005. 

 Sensor Light Response – the dishwasher is loaded with 8 place settings plus 6 serving pieces. 

One of the place settings is soiled with half of the soil load specified for a single place setting 

according to ANSI/AHAM DW-1-2005. 

During each test cycle, machine electrical energy consumption and water consumption is 

measured. In addition, for each dishwasher, standby power is measured. In order to calculate EF 

and annual energy consumption according to the DOE test procedure, the following calculations 

for machines without truncated normal cycles are performed. 

For non-soil-sensing machines, the machine electrical energy consumption M is simply 

the measured kWh consumed per cycle. For soil-sensing dishwashers, the machine electrical 

energy consumption is a weighted average defined as: 

M = (Mhr x Fhr) + (Mmr x Fmr) + (Mlr x Flr) where, 

Mhr = the machine electrical energy consumption for the sensor heavy response test in kWh 

Mmr = the machine electrical energy consumption for the sensor medium response test in kWh 

Mlr = the machine electrical energy consumption for the sensor light response test in kWh 

Fhr = the weighting factor based on consumer use of heavy response = 0.05 

Fmr = the weighting factor based on consumer use of medium response = 0.33 

Flr = the weighting factor based on consumer use of light response = 0.62 

In addition to the machine electrical energy consumption, the EF calculation includes the 

energy required to heat the water used in the cycle. For purposes of calculating EF, it is assumed 

that the water is heated electrically. The water energy consumption V in gallons per cycle is 

based upon the water consumption measured during the normal cycle. For non-soil-sensing 

machines, V is the number of gallons measured during the test cycle. For soil-sensing 

dishwashers, the water consumption is: 

V = (Vhr x Fhr) + (Vmr x Fmr) + (Vlr x Flr) where, 

Vhr = the water consumption for the sensor heavy response test in gal/cycle 

Vmr = the water consumption for the sensor medium response test in gal/cycle 

5-24 

EE-2006-STD-0127 COMMENT 39.2
L 

Vlr = the water consumption for the sensor light response test in gal/cycle 

All of the units were rated for a nominal 120 °F inlet water temperature. Thus, for both 

soil-sensing and non-soil-sensing machines, the water energy consumption W in kWh for 

electrically-heated water is defined as: 

W = V x T x K where, 

T = the nominal water heater temperature rise = 70 °F 

K = the specific heat of water in kWh per gallon per °F = 0.0024 

Finally, EF, expressed in cycles per kWh, is derived from machine and water energy 

consumption according to: 

E = 1/(M + W) 

Estimated annual energy consumption (EAEU) incorporates not only energy used during 

dishwashing operations, but standby power throughout the year as well. For all dishwashers with 

normal cycles, EAEU is defined as: 

EAEU = (M + W) x N + S where, 

N = the representative average dishwasher use as defined by DOE = 215 cycles/yr 

S = the annual standby electrical energy in kWh per year, defined by: 

S = Sm x ((Hs)/1000) where, 

Sm = the average standby power in watts; and 

Hs = H – (N x L) where, 

H = the total number of hours per year = 8766 hours per year 

= the average duration of the normal cycle for non-soil-sensing dishwashers and the 

average duration of the sensor light response, sensor medium response, and sensor heavy 

response for soil-sensing dishwashers 

Unfortunately, unit #6 developed control board problems before testing could be 

completed. Therefore, further performance analysis for data validation purposes was limited to 

rated EFs between .58 and .93 (test units #1 through #5). However, test unit #6 was still subject 

to teardown and costing analysis. 

Additional instrumentation was provided during these tests to measure disaggregated 

component energy consumption in order to assess which design options could have the greatest 

impact on efficiency. Watt meters were attached to the following major components which 

together account for virtually all of the electrical usage of the dishwasher: 

5-25 

EE-2006-STD-0127 COMMENT 39.2
 heating element; 

 main pump motor;

 drain pump motor, if the dishwasher had dual pumps, and; 

 vent blower, if the dishwasher was equipped with convective drying. 

Overall trends in key parameters of the dishwashers under DOE testing are shown in 

Figure 5.6.2, including average cycle times, machine electrical energy consumption, water 

consumption, and standby power. Machine electrical energy and water consumption are 

weighted averages calculated in accordance with the DOE test procedure. Cycle time and 

standby power are simple averages of the 3 tests, with standby power taken as the average power 

measured immediately after the conclusion of the normal cycle. 

6.0 

5.0 

4.0 

3.0 

2.0 

1.0 

0.0 

Consumption, kWh

Cycle Time, hours 

Machine Electrical Energy 

Water Consumption, gallons 

Standby Power, W 

0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 

Rated EF, cycles/kWh 

Figure 5.6.2 Overall Dishwasher Cycle Parameters versus EF 

The data show that, with the exception of unit #2 with a rated EF of 0.64, there are 

relatively consistent trends for machine electrical power consumption and water consumption as 

a function of EF. Unit #2 is somewhat anomalous but its divergent water versus energy-use 

strategy may be explained due to the use of a fixed electromechanical timer program in that unit. 

A plausible explanation could be that the “program” embedded into the various cam shafts of 

that timer might be an “older” program. The electronic units have the benefit of easilyreconfigurable electrically-erasable programmable read-only memory devices (EEPROMs), 

allowing a manufacturer to reprogram its dishwasher line at much lower cost. Some dishwashers 

that DOE examined even had infrared (IR) receivers and transmitters in the user interface, 

potentially allowing the reprogramming of units in the field. 

5-26 

EE-2006-STD-0127 COMMENT 39.2
Excluding the performance of unit #2, there is almost a linear function for water and 

machine electrical energy consumption versus EF. Similarly, standby power generally increases 

with increasing EF. This is likely due to the more complex displays and user interfaces typically 

associated with higher-end machines. Cycle time shows less of a correlation, as cycle times may EAEU kWh/yr 

be limited by consumer acceptance. In addition, as platforms are pushed to higher and higher 

efficiencies, the thermal drying process is aided either via active-vent systems that open the 

cavity to the kitchen, or even power-vent systems that actively pull cooler and drier kitchen air 

through the cavity, which reduces the required final rinse water temperature 

On an EAEU basis, the correlation with EF becomes much more consistent, as shown in 

Figure 5.6.3. The somewhat lower EAEU for the 0.64 EF machine may be explained in part by 

the electromechanical timer inside that dishwasher. Such timers consume no energy when they 

are not in use, whereas the electronic boards found in all other dishwashers may do so in order to 

keep displays, status knobs, and other aspects of the user interface lit and active. 

450 

400 

350 

300 

250 

200 

150 

100 

50 

0 

0.4 0.5 0.6 0.7 0.8 0.9 1 

Rated EF cycle/kWh 

Figure 5.6.3 Dishwasher EAEU versus EF 

Time-resolved data from the watt meters allowed each component’s energy consumption 

to be ascertained for different segments of the cycle as well as for the entire cycle. Figure 5.6.4 

shows the component energy usage per overall cycle for each of the test units. Each value is 

obtained via simple averages of the data from the 3 tests for each dishwasher; no weighting 

based on soil load was applied for soil-sensing machines in order to provide a consistent means 

of comparison among the test units. Machine electrical energy consumption and water 

consumption, however, are both reported elsewhere in this section as weighted averages in 

accordance with the DOE test procedure. It can be seen from Figure 5.6.4 that the heating 

5-27 

EE-2006-STD-0127 COMMENT 39.2
element is by far the largest contributor to machine electrical energy consumption, and therefore 

optimization of its usage and design will have a significant effect on efficiency. The main pump 

energy consumption has a second-order impact, while the drain pump and vent blower (if any) 

have negligible effect on electrical energy consumption. 

0 

0.2 

0.4 

0.6 

0.8 

1 

1.2 

kWh Energy Consumption, 

0.58 0.64 0.68 0.78 0.93 

Rated EF, cycles/kWh 

Heater Main Pump Drain Pump Vent B ower l

Figure 5.6.4 Dishwasher Machine Electrical Energy Consumption 

Disaggregated by Component 

Figure 5.6.5 examines water consumption, since water energy consumption contributes to 

EF along with machine energy consumption. In constructing this graph, the gallons consumed 

during the overall cycle were broken down into separate fill events. Since it is difficult to 

distinguish a pre-rinse, wash, and rinse portion of the cycle, the fill events were qualified only as 

a heated or unheated fill. The fills did not necessarily occur in the order that is displayed in the 

graph; for example, a particular cycle may consist of several unheated fills, a heated fill, another 

unheated fill, and a final heated fill. However, since fill strategies varied significantly from 

model to model, in order to compare water usage across all models this simplified graphing 

approach was taken. 

5-28 

EE-2006-STD-0127 COMMENT 39.2
6

5

Water Consumption, gallons/cycle 4

3

2

1

0

0.58 0.64 0.68 0.78 0.93 

Rated EF, cycle/kWh 

Thi

First Unheated Fill Second Unheated Fill Third Unheated Fill 

Fourth Unheated Fill Fifth Unheated Fill First Heated Fill 

Second Heated Fill rd Heated Fill Fourth Heated Fill 

Figure 5.6.5 Dishwasher Water Consumption Disaggregated by Cycle 

Segment 

The data show that different water usage strategies allow improvement in EF. First, 

reducing the size of each fill clearly will reduce water consumption and thus water energy 

consumption, since less energy is required to heat the volume of water both in the water heater 

and with the booster heater in the dishwasher. Second, the total number of fills may be reduced. 

For instance, moving from the 0.58 to the 0.68 EF unit eliminated one heated fill. Finally, the 

relative proportions of heated and unheated fills may be adjusted. Creating a cycle with more 

unheated fills instead of heated ones means that less electrical energy will be expended to heat 

the water. However, this also means that in order to maintain wash performance, the dishwasher 

will have a greater reliance on mechanical action to loosen soil and require better filtration in 

order to prevent re-deposition of food particles while contending with the reduced cleaning effect 

from thermal or chemical energy, via the detergent. 

Once again, there is an incongruity between unit #2 and the units at adjacent efficiency 

levels. This machine trades off higher-than-expected water consumption with lower-thanexpected heater electrical energy input to achieve its EF. To achieve this with 4 heated fills of 

approximately 1 gallon each requires a reduced water temperature for at least some of the fills. 

When average tub temperatures are measured for each heated cycle segment, the temperature for 

unit #2 ranged from 4 °F to 22 °F lower than those for comparable cycle segments in the other 

units. As discussed previously, this performance trade-off may be due entirely to the controller 

in the unit, since the other physical differences between the (electromechanical) 0.64 EF unit and 

the (electronic) 0.58 EF unit are minimal. 

5-29 

EE-2006-STD-0127 COMMENT 39.2
To summarize key findings from the testing of a small number of dishwashers, DOE 

observed that: 

 Electrical energy consumption was inversely correlated with water consumption, so that the 

higher-EF dishwashers used less water. 

 The higher-EF machines tended to have higher standby power consumption, but on an EAEU 

basis there was still a consistent downward trend as a function of EF 

 The higher-EF machines did not necessarily have longer cycle times and they usually 

supplemented resistance heat with active-vent systems or even fan-assisted drying systems. 

Compared to the power draw of the resistance element, the power required to activate a wax 

motor for vent opening and perhaps a small fan motor is minimal. 

 The vast majority of electrical energy consumption during the cycle was attributable to the 

heating element. Energy consumption of the main pump was secondary, and energy 

consumption from the drain pump and venting mechanism were negligible. Therefore, 

design strategies that improve heater efficiency or reduce the quantity of water to be heated 

have a high impact on EF. Heater configurations are discussed further in the market and 

technology assessment (Chapter 3 of the TSD). 

 The higher-EF machines tended to have more fills per cycle, but less water consumption per 

fill, so that the total water consumption was lower. Design features to reduce the water 

required per fill are discussed in the market and technology assessment (Chapter 3 of the 

TSD). 

 The higher-EF machines with more fills tended to have fewer and/or shorter heated ones. 

They relied more on pre-soaking the dishware, utilizing mechanical energy for a greater 

percentage of soil removal. Fewer and shorter heated cycle segments again reduce the 

overall energy consumption. 

5.6.1.3 Product Teardown 

Costs 

DOE tore down the previously-tested dishwashers to identify design options that can be 

used to raise EF and their associated costs. DOE also tore down an additional 0.72 EF unit that 

shared the same platform as some of the tested units. This last dishwasher was not yet available 

on the market at the time of testing but was released for high-volume manufacturing 3 weeks 

later. The teardown units spanned the range of efficiencies given in section 5.4.2. Table 5.6.5 

compares the incremental efficiency levels and EFs of DOE’s teardown units. 

DOE selected a range of dishwashers that utilized the same platform in order to provide a 

consistent basis of comparison for design options. The first 4 units (EFs of 0.58, 0.64, 0.68 and 

0.72) shared one platform based on the same plastic tub and sump, while the other 3 units shared 

5-30 

EE-2006-STD-0127 COMMENT 39.2
a stainless-tub platform that was almost identical among the 3 models. DOE did not tear down a 

baseline (0.46 EF) unit because DOE was not aware of a baseline unit which shared a platform 

with higher-efficiency machines. 

Table 5.6.5 Comparison of Dishwasher Incremental Efficiency Levels and Teardown 

Unit EFs 

Incremental Efficiency Level, EF 

(cycle/kWh) Teardown Unit EF (cycle/kWh) 

0.58 0.58 

0.62 0.64 

0.65 0.68 

0.68 0.72 

0.72 0.78 

0.80 0.93 

1.11 1.11 

After tearing the units down, DOE grouped production costs into the categories shown in 

Figure 5.6.6. To protect sensitive manufacturing information, DOE does not display absolute 

costs. Note that combined material costs (raw material and purchased parts) typically account 

for 60 percent to 70 percent of the production cost. 

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0% 

EF, Cycles/kWh 

Figure 5.6.6 Dishwasher Full Production Cost Distributions 

Maintenance Costs 

Costs 

Building 

Tooling 

Purchased Parts 

0.58 0.64 0.68 0.72 0.78 0.93 1.11 Raw Material

% of Total Production Cost 

Insurance Costs 

Property Tax 

Utility Costs 

Indirect Process 

Depreciation 

Depreciation 

Equipment 

Depreciation 

Fabrication Labor 

Assembly Labor 

As can be observed in Figure 5.6.6, the importance of raw materials declines for a given 

platform as design options are added via purchased parts. As the complexity of a washer 

5-31 

EE-2006-STD-0127 COMMENT 39.2
increases, the assembly costs also rise. The higher raw material costs for the 3 higher-efficiency 

dishwashers are largely attributable to the stainless steel tub material. 

DOE also broke the material costs down by component subsystem, as shown in Figure 

5.6.7. As expected, the cavity and door assemblies are a major cost component. However, the 

proliferation of design options steadily decreases the percentage cost contribution of doors and 

cavities as dishwasher platforms are pushed to higher and higher efficiency levels. 

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0% 

/

i

0.58 0.64 0.68 0.72 0.78 0.93 1.11 

EF Cycles/kWh 

% of Material Costs 

Final Boxing 

Final Assembly 

Rack Assemblies 

Vent Blower 

Assembly 

Front Door & 

Soap Rinse 

Dispenser 

Control System & 

Wir ng Harness 

Main Pump + Dist. 

Drain Pump & Hoses 

Main Cavity & 

Frame 

Figure 5.6.7 Dishwasher Material Cost Distributions 

Design Options 

For each unit subject to teardown, DOE noted all aspects of construction as described in 

section 5.5.3.1, including design options and how they were implemented. DOE grouped the 

design options for residential dishwashers into 5 major categories as noted in Table 5.6.6: (1) 

insulation, (2) water system, (3) sprayer design, (4) heating system, and (5) controls. In addition 

to the design options noted in Table 5.6.6, DOE noted platform design approaches, such as tub 

material and sump design, to help identify how platform changes allow manufacturers to reduce 

water requirements. 

The 2 platform families subject to teardown were representative of units that span a wide 

range of efficiencies, but the sample size is small compared to the number of different washer 

platforms on the U.S. market today. 

5-32 

EE-2006-STD-0127 COMMENT 39.2
Table 5.6.6 Design Options on Dishwasher Teardown Units 

Energy Factor 

Category Detail 0.58 0.64 0.68 0.72 0.78 0.93 1.11 

Insulation 

by 

Cavity-Top 

and Sides 

Cavity-Back 

Yes 

No 

No 

No 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Location Cavity-Bottom No No No No Yes Yes Yes 

Door No No No Yes Yes Yes Yes 

# of Main 

Pump Speeds 1 1 3 3 1 1, Triac 1, Triac 

Water Supply 

Tubing Loc. Exterior Exterior Exterior Exterior Interior Interior Interior 

Water Water Meter No No No No Yes Yes Yes 

System Multi-Spray / 

Diverter Valve Yes Yes Yes Yes No Yes Yes 

Float Switch Yes Yes Yes Yes No No No 

Sump Pressure 

Transducer No No No No No Yes Yes 

Sprayers 

by Cavity 

Location 

and Type 

Bottom 

Middle 

Top 

Plastic 2­

Arm 

Plastic 

2-Arm 

Plastic 

Spray 

Nozzle 

Plastic 2­

Arm 

Plastic 2­

Arm 

Plastic 

Spray 

Nozzle 

Plastic 3­

Arm 

Plastic 2­

Arm 

Plastic 

2-Arm 

Plastic 

3-Arm 

Plastic 

2-Arm 

Plastic 

2-Arm 

Stainless 

2-Arm 

Stainless 

2-Arm 

None 

Stainless 

2-Arm 

Stainless 

2-Arm 

None 

Stainless 

2-Arm 

Stainless 

2-Arm 

Cutlery 

Tray 

Sprayer 

Heating Heater Type Tubular Tubular Tubular Tubular FlowThrough 

FlowThrough FlowThrough 

Type Electronic 

ElectroMechanical 

Electronic Electronic Electronic Electronic Electronic 

Thermocouple No No Yes Yes Yes Yes Yes 

Controls Soil Sensor 

Humidity 

Sensor 

No 

No 

No 

No 

Yes 

No 

Yes 

No 

No 

No 

No 

No 

Yes 

Yes 

Vent 

Technology None None 

Active 

Door 

Vent 

FanAssisted 

Vent 

None 

FanAssisted 

Vent 

FanAssisted 

Vent 

Platform changes involve changing the overall system architecture, and typically result in 

reduced fill levels in the cavity. As shown by Figure 5.6.4, water heating drives energy 

consumption. Thus, any effort to reduce water usage will reduce energy consumption. DOE 

5-33 

EE-2006-STD-0127 COMMENT 39.2
also observed that platform design is the limiting factor in achieving a higher EF, meaning that a 

machine that uses even the most-efficient components will not achieve a high EF if it has a 

lower-efficiency platform design. This observation was confirmed during manufacturer 

interviews. 

Platform changes give a manufacturer the opportunity to dramatically impact the wateruse requirements per fill. The smaller the sump and water distribution system volume, the less 

water a dishwasher needs. The higher-EF platform chosen for the testing and analysis was thus 

able to have more fills per cycle, yet consume less water per cycle than the less-efficient 

platform. However, reducing the sump volume and filter area comes with a risk of clogging via 

food particles and other debris. To address this risk, the higher-EF platforms incorporate a sump 

pressure transducer that signals the controller whenever the filtration elements need to be 

backwashed. 

Whereas most dishwashers currently manufactured in the U.S. rely on macerators and 

partially bypass their filters during washing and rinsing operations, European dishwasher designs 

generally filter 100 percent of the water that is about to enter the sump pump and distribution 

system. By filtering the water with fine filters, European designs benefit from being able to use 

smaller arm nozzles and distribution pipes without the potential for clogging them with food 

particles. Locating the pipes inside the wash cavity further reduces the length and hence the 

water volume required to fill these pipes. 

Electronic controllers combined with water meters allow a dishwasher to dose water very 

precisely, regardless of water supply pressure. If a dishwasher uses a sump pressure transducer 

to periodically back-flush clogged filters, the knowledge of how much water the drain pump can 

move in a given amount of time also allows the controller to precisely refill the sump after each 

back-flush. Sensing the build-up of filter-clogging particles via the transducer also gives the 

controller an opportunity to vary its cleaning program according to various algorithms, which 

can provide similar soil-sensing functionality as a turbidity sensor. 

Within a platform, EF-reduction options include using multi-speed pumps that can 

operate at speeds optimized for each operating condition. Pumps may use higher pressure to 

help knock food particles off the dishware, for example, while reserving lower pump speeds for 

rinse cycles. 

Manufacturers also vary the number of sprayers and the number of arms per sprayer 

inside the cavity. The lower-efficiency unit within the lower-efficiency platform had 2 sprayers, 

one of which was filled via a spray nozzle in the roof of the cavity. The higher-efficiency units 

within this platform incorporated sprayers with more arms, which were connected directly to the 

sump pump (as opposed to an open-air nozzle), and included an additional sprayer mounted to 

the roof of the cavity. However, the higher-efficiency platform washers all had identical 2­

armed sprayers which were made of stainless steel as opposed to plastic. While the highestefficiency unit had a spray system under the roof of the cavity, its primary function was to direct 

spray to a cutlery rack located directly underneath it. 

5-34 

EE-2006-STD-0127 COMMENT 39.2
Adding insulation or changing insulation materials in the cabinet cuts down on heat 

losses, thus requiring less energy consumption by the heater. DOE observed incremental 

changes in insulation location and type as a function of EF. Lower-efficiency units did not 

appear to have insulation at all. Higher-efficiency units added insulation to the top, sides, and 

bottom of the cabinet and the door. Manufacturers also used several different insulation 

materials: polypropylene blankets, open-cell polyurethane foam, and rubberized asphalt with and 

without cotton or foam backing. The decision to adopt rubberized asphalt seems to be driven 

largely by the desire for sound-attenuation. 

As shown in Figure 5.6.4, water heating consumes the most energy during a wash cycle. 

Thus, in addition to reducing the amount of water required, changing heater design can reduce 

energy consumption. The heater design change that has the most effect on both water and 

machine energy consumption is switching from a tubular supplemental heater to a flow-through 

heater. The tubular supplemental heater design requires a certain amount of water to be in the 

bottom of the tub. Flow-through designs heat the water as it flows from the sump to the sump 

pump and require much less water volume. However, tubular and flow-through heaters are not 

interchangeable technologies, so changing to a flow-through design requires a platform redesign. 

Drying strategy also influences EF. Drying can be achieved via an exposed tubular 

supplemental heating element or by heated rinse cycles that can raise the dishware temperatures 

high enough to drive off moisture. The drying process may be aided by louvers in the door that 

are opened via wax motors. Optional fans can draw relatively cool, dry kitchen air into the 

dishwasher cavity through these openings. Some dishwasher designs feature “condensation” 

drying systems that use cooled cavity walls to remove latent heat inside the dishwasher cavity 

via condensation of the moisture. The cavity walls may be cooled via cold intake water (for 

washers that feature a cold-water connection, as is typical in Europe) or active-fan systems that 

draw relatively cooler kitchen air over the cavity walls. A humidity sensor can provide feedback 

to the controller as to when the contents of the cavity are dry. 

DOE also studied control components and strategy as a means for increasing EF. Section 

5.6.1.2 discussed various observed control strategies in the tested dishwashers, such as reducing 

the total number of cycles and adjusting the relative proportions of heated and unheated fills, but 

these strategies do not require different components and would be reflected as development 

expenditures, not incremental costs. However, during the teardowns DOE did observe specific 

control components that influence EF. Some units have soil sensors, which allow the machine to 

sense the wash water turbidity, infer the cleanliness of the dishware, and possibly reduce the 

required number of cycles or adjust water levels and temperatures accordingly. Also, all higherEF units feature thermocouples to measure temperature for closed loop control. This 

thermocouple was observed to be located in either the door or inside the sump on the teardown 

units. Better water temperature control results in less energy used for water heating and more 

consistent wash performance. 

5-35 

EE-2006-STD-0127 COMMENT 39.2
Cost-Efficiency Comparison 

Using the calculated production costs, DOE generated a cost-efficiency curve to compare 

with the data AHAM submitted. As mentioned previously, DOE is unaware of any baseline 0.46 

EF units on the market with a similar platform as a more efficient unit. As a consequence, DOE 

did not tear down a 0.46 EF unit, and the baseline for DOE’s cost-efficiency curve is a 0.58 EF 

unit. For comparison to the AHAM data, DOE recalculated AHAM’s incremental costs based 

upon a baseline of 0.58 EF. 

The purpose of comparing DOE’s results to the AHAM-submitted data was to assess the 

reasonableness of AHAM’s data rather than attempt to duplicate them. DOE’s teardown sample 

size was very small and could not be expected to adequately capture the variability of all 

products in the marketplace. In addition to small sample size, DOE’s results were influenced by 

the choice of platforms. DOE’s teardown analysis and manufacturer interviews confirmed that 

upgrading components can only raise EF to a certain point for a given platform, and that overall 

system architecture limits EF. The platform which DOE reverse-engineered is among the most 

efficient available from large-volume manufacturers (with an EF that spans the range of 0.58 to 

0.72). Thus, it is reasonable to assume that starting from a lower-efficiency platform, as did the 

units in AHAM’s dataset, will result in higher incremental costs. If the reverse-engineering 

sample size had been larger, it is reasonable to assume that the range of incremental costs by 

efficiency level would have broadened. As a result, DOE feels that the AHAM submission is 

reasonable and reflective of the gamut of dishwasher platforms and their inherent efficiencies on 

the market today. 

Figure 5.6.8 and Figure 5.6.9 compare AHAM’s and DOE’s cost-efficiency curves for 

dishwashers, normalized for a baseline EF of 0.58. Figure 5.6.8 presents the curves across the 

range of EFs for which AHAM provided data (0.58 to 0.72 EF), while Figure 5.6.9 shows the 

same data across the complete range of EFs that DOE examined (0.58 to 1.11EF). 

5-36 

EE-2006-STD-0127 COMMENT 39.2
$-

$10 

$20 

$30 

$40 

$50 

$60 

$70 

$80 

$90 

[$] Incremental Production Cost

AHAM - Min 

AHAM - Avg 

AHAM - Max 

DOE 

0.55 0.60 0.65 0.70 0.75 

EF 

Figure 5.6.8 Comparison of Dishwasher Incremental Costs for the 

Efficiency Levels in AHAM’s Submittal, 0.58 EF Baseline 

$-

$20 

$40 

$60 

$80 

$100 

$120 

$140 

$160 

$180 

$200 

[$] Incremental Production Cost 

AHAM - Min 

AHAM - Avg 

AHAM - Max 

DOE 

0.55 0.65 0.75 0.85 0.95 1.05 1.15 

EF 

Figure 5.6.9 Comparison of Dishwasher Incremental Costs for EF = 0.58 

to 1.11, 0.58 EF Baseline 

Table 5.6.7 tabulates the incremental manufacturing costs for residential standard 

dishwashers as a function of EF for all efficiency levels above the baseline of EF = 0.46. Since 

this data is not normalized to a baseline of 0.58, the values will be higher than those presented in 

the previous figures by the cost increment between EF = 0.46 and 0.58 ($4.01). The cost 

increment at EF = 0.80 was obtained by interpolating the DOE cost curve between EF = 0.78 and 

0.93. Table 5.6.7 contains the cost-efficiency data that is used in subsequent analyses. 

5-37 

EE-2006-STD-0127 COMMENT 39.2
Table 5.6.7 Incremental Manufacturing Costs for Residential Standard Dishwashers 

Product Class: Standard 

Energy Factor (cycles/kWh) Incremental Cost 

Baseline -

0.58 $4.01 

0.62 $7.38 

0.65 $14.00 

0.68 $30.35 

0.72 $71.38 

0.80 $133.29* 

1.11 $184.67* 

* The LCC analysis utilized values for these levels that were normalized to a baseline EF = 0.58, so that each cost 

was $4.01 lower. The LCC analysis for the NOPR will correct these values. 

5.6.1.4 Manufacturer Interviews 

DOE conducted interviews with dishwasher manufacturers to develop a better 

understanding of the technologies used to improve the energy efficiency of dishwashers. These 

interviews also helped DOE analyze the results of the performance testing and ask clarifying 

questions resulting from the dishwasher teardowns. During interviews, manufacturers were 

asked what combinations of design options would be required to increase the energy efficiency 

of dishwashers in order to meet the efficiency levels proposed for dishwashers in section 5.4.2. 

The discussion helped DOE understand what proposed design options have already been 

implemented and what additional design options DOE should consider. Additionally, the 

interviews provided a better understanding of the design strategies underlying the AHAM 

dishwasher data submittal. The discussion below represents a consolidation of the responses in 

order to avoid revealing design details, component costs, and other sensitive information for any 

given manufacturer. 

Background Information 

The dishwasher market is characterized by the dominance of Energy Star-rated units. 

Many manufacturers offer a 90 percent or greater Energy Star-compliant product line. 

Therefore, efficient technologies dominate, and baseline dishwashers do not represent the 

majority of product offerings, although multiple manufacturers stressed that baseline 

dishwashers represent a significant portion of sales. In addition to the prevalence of Energy Star 

products, multiple dishwasher manufacturers specialize in high-end units which have features 

such as stainless steel cavities and electronic controls as standard features. 

0.46 EF Baseline Efficiency Level 

All manufacturers interviewed significantly exceed the baseline, minimally-compliant 

energy efficiency level with most of their dishwasher models. Most baseline dishwashers use 

electromechanical controls instead of the electronic controls prevalent in higher-efficiency 

5-38 

EE-2006-STD-0127 COMMENT 39.2
designs. Dishwashers lacking electronic controls cannot use soil sensors, thermocouples, water 

meters, pressure transducers, or other such features to reduce their annual energy use. Baselineefficiency dishwashers generally feature a plastic cavity instead of the more costly stainless steel 

designs found on higher-end dishwashers, although this feature does not significantly impact 

energy (or water) performance. Manufacturers that offer low-end baseline dishwashers 

mentioned that within this market segment, consumers are more likely to accept fewer features 

and poorer wash performance than consumers purchasing premium dishwashers. 

Baseline dishwashers are primarily associated with older design platforms which 

inherently make it difficult to improve energy (and water) efficiency beyond a certain point. 

These characteristics include a compactor-style drain and filter system, fewer spray arms, and a 

cavity and sump design that requires a relatively large quantity of water. Additionally, low-end 

baseline dishwashers may use multiple water changes to compensate for less-effective filtration. 

0.58 EF Efficiency Level 

This efficiency level corresponds to the 2006 Energy Star level. Since many retailers 

require Energy Star qualification for all the dishwashers they sell, manufacturers regard the 

Energy Star qualification level as the de-facto standard. In order to meet this proposed standard 

level, manufacturers reduce the fill level in the wash cavity, since hot water consumption 

represents a significant portion of dishwasher energy consumption. To reduce the fill level, 

multiple manufacturers reduce the volume of the dishwasher sump; reduce the internal wetted 

volume of the pump, hydraulic tubing, and spray arms; and design the spray-arm jets to clean 

more effectively with less water. The design features described may be, but are not necessarily, 

associated with substitution technologies. The features may also be integral to newer platform 

designs. Multiple manufacturers stated that electronic controls are not necessary to meet the first 

proposed standard level. Multiple manufacturers also stated that soil sensors are not necessary to 

meet the first proposed standard level. 

0.65 EF Efficiency Level 

This is the 2007 Energy Star level. Manufacturers expressed concern about their ability 

to meet this standard level with their low-end product line based on older-generation design 

platforms. These older platforms can be altered with some efficiency-increasing technologies, 

like optimized hydraulic systems, but significant changes to the filtration system or the sump, 

both integral parts of the platform, require a costly redesign involving research and development 

(R&D), tooling changes, and perhaps even a factory and equipment redesign. The costs 

associated with a redesign represent a step function rather than an incremental increase. 

To reach an EF of 0.65, manufacturers further optimize the hydraulic system to reduce 

the water fill level required. For example, one design strategy consists of alternately using the 

top and bottom spray arms, thus reducing the amount of water in circulation and reducing the 

water required in each fill. 

Multiple manufacturers stated that while cost-sensitive consumers may accept some 

performance sacrifice to meet energy conservation standards, manufacturers were uncomfortable 

5-39 

EE-2006-STD-0127 COMMENT 39.2
with the performance sacrifices that might be necessary to meet the 0.65 EF level without large 

cost increases. Drying energy, while associated with significant energy consumption, was not 

viewed as a major area of possible improvement. It was noted that while some European highefficiency dishwasher models use condensation drying, this is less effective in the U.S., since 

U.S. dishwashers are plumbed into the hot water line and therefore cannot maintain a cold water 

reservoir to assist the condensing process. Sacrificing drying performance is not an option 

manufacturers are willing to contemplate even if this meant they could save energy on the heated 

drying portion of their wash cycle. 

Multiple manufacturers stated that consumers of higher-end dishwashers will not tolerate 

either reduced washer performance or longer washing cycles. Thus, reducing the overall energy 

consumption through longer drying cycles via active vents or by alternating spray patterns is 

limited by consumer acceptance. 

For higher-end dishwashers, manufacturers use multiple strategies to meet this proposed 

standard level without sacrificing performance. Several manufacturers stated that electronic 

controls are required to achieve this proposed standard level, since multiple energy-savings 

opportunities arise from control strategy changes. However, the 0.64 EF test unit that DOE tore 

down featured an electromechanical controller, suggesting that inherently-efficient platforms 

may be able to achieve a 0.65 EF while avoiding the need for an electronic controller. 

Soil sensors and/or sump pressure transducers are frequently used to control wash cycles 

at this efficiency level. In order to maintain wash performance, manufacturers use a more 

advanced water filtration system to reduce the number of water fills required per wash cycle and 

shrink the size of nozzles, distribution piping, sump volume, pump, and inline heater to minimize 

wetted volume. Filtration systems with small mesh sizes and minimized surface area carry some 

performance risk, however, as users can overload these systems more easily with excess soil left 

on dishware. Pressure transducers can help mitigate that risk by sensing the build-up of soil and 

flushing the filter as needed. Multiple manufacturers stated that they cannot add electronic 

controls and soil sensors to low-end dishwashers while maintaining their price point. 

One manufacturer noted that as the mass of water inside the dishwasher is minimized, the 

amount of energy required to heat the water inside the dishwasher above its inlet temperature is 

reduced. Thus, platforms that have minimized water requirements by design can heat the water 

to higher temperatures for the same amount of energy, improving wash performance. 

Dishwashers with inline heaters heat the dishware during the final rinse cycle to drive off 

moisture, while those using tubular heating elements can heat the dishware either via the rinse or 

by subsequent convective and radiant drying inside the cavity. Either heating strategy can be 

aided by active-vent doors or blowers after the final rinse cycle. 

1.0 EF Efficiency Level 

To meet this efficiency level, conserving water is essential, since hot water consumption 

drives energy consumption. Multiple manufacturers stated that this standard level would be very 

difficult to meet, even with high-end dishwasher features, without sacrificing wash performance. 

5-40 

EE-2006-STD-0127 COMMENT 39.2
Manufacturers stated that electronic controls and soil sensors would be required on all 

dishwashers to meet this proposed standard level. Some manufacturers commented that meeting 

this standard level would require a complex wash-cycle control decision tree, which increases the 

chance that the dishwasher controller will make a decision tree error, reducing dishwasher 

performance. Reducing water temperature would help meet this proposed standard level, but this 

option is only available in Europe, where dishwashers are plumbed into the cold water line. 

Several product utility concerns were expressed by manufacturers. Some manufacturers 

stated that in order to decrease energy and water consumption, cycle times would have to be 

increased, and that consumers have an incorrect perception that longer cycle times indicate 

greater energy consumption. One manufacturer commented that at these high standard levels 

there is increased risk that some manufacturers would introduce a highly-efficient but poorlyperforming ‘normal’ wash cycle, since this is the cycle measured by the DOE test procedure. 

Consumers might then select a less-efficient wash cycle, negating some of the assumed energy 

savings. 

Since many higher-end dishwashers are potentially simple to re-program in the field, the 

service representatives have the opportunity to modify a dishwasher’s performance at the 

expense of energy consumption. For example, the dishwasher may be programmed to raise 

water temperatures to improve its soil-removal characteristics. Such field modifications would 

be hard to detect or prevent, and could negate much of the energy savings potential intended by 

the rulemaking. 

Intellectual Property 

During discussions with DOE, no dishwasher manufactures expressed significant 

concerns about intellectual property and patent infringement at the first and second proposed 

standard levels. However, one manufacturer expressed concern that there might be some 

intellectual property obstacles at the highest proposed standard level. 

5.6.2 Dehumidifiers 

The dehumidifier engineering analysis was performed by considering cost and efficiency 

information from multiple sources. AHAM provided incremental manufacturing costs for all but 

the highest efficiency levels for the 3 product classes for which data was submitted. DOE 

supplemented these data points by conducting its own detailed dehumidifier teardowns and 

estimating the manufacturing costs of observed efficiency features. DOE also conducted 

interviews with dehumidifier manufacturers to obtain greater insight into design strategies and 

their associated costs to improve efficiency. 

5.6.2.1 AHAM Data 

In support of the dehumidifier rulemaking, AHAM collected incremental manufacturing 

cost data from its member companies and submitted them to DOE. The data submitted by 

AHAM represents the aggregate input from the producers of over 95 percent of the covered 

5-41 

EE-2006-STD-0127 COMMENT 39.2
dehumidifiers sold in the U.S. AHAM did not provide any data for the product class of 75.00 

pints/day or greater, due to insufficient data to protect confidentiality. Table 5.6.8 describes 

overall unit shipments from 2003 to 2005 by capacity range. Other than the product class of 

25.00 pints/day or less, each dehumidifier product class experienced shipment growth in that 

time period. 

Table 5.6.8 AHAM Dehumidifier Shipments Data Submittal 

Year Shipments, Domestic + Imports (thousands of units) by Capacity (pints/day) 

≤ 25.00 25.01-35.00 35.01-45.00 45.01-54.00 54.01-74.99 ≥75.00 

2003 178 282 307 289 255 -

2004 169 389 395 343 376 -

2005 127 509 455 406 460 -

Table 5.6.9 details the shipment-weighted average energy efficiency of dehumidifier 

shipments from 2003 to 2005 by capacity. All product classes other than that for 25.01 - 35.00 

pints/day recorded EF improvements over that time period. 

Table 5.6.9 AHAM Dehumidifier Shipment-Weighted Efficiency Data Submittal 

Year Shipment-Weighted Average Energy Efficiency (liters/kWh) by Capacity (pints/day) 

≤ 25.00 25.01-35.00 35.01-45.00 45.01-54.00 54.01-74.99 ≥75.00 

2003 1.25 1.26 1.35 1.48 1.56 -

2004 1.27 1.27 1.38 1.56 1.56 -

2005 1.28 1.26 1.42 1.57 1.57 -

In addition to total shipment and shipment-weighted average energy efficiency for 

dehumidifiers, AHAM also submitted 2 tables of data disclosing market share by efficiency level 

and year. Table 5.6.10 discloses market share from 2003 to 2005 for dehumidifiers in the 35.01-

45 pints/day product class, while Table 5.6.11 details the same type of data for the 54.01 to 74.99 

pints/day product class. 

Table 5.6.10 AHAM Dehumidifier Market Share Data Submittal for 35.01 to 45.00 

Pints/Day 

Efficiency Bin (liters/kWh) Market Share by Year (percent) 

2003 2004 2005 

< 1.30 

1.30-1.34: Baseline = 1.30 70% 54% 27% 

1.35-1.39: Mid Point = 1.35 35% 

1.40-1.44: EPACT 2005=1.40 4% 

1.45-1.49: Suggested =1.45 26% 38% 

1.50-1.59: Suggested = 1.50 8% 38% 

> 1.59: Max Available = 1.74 

< 1.30 

5-42 

EE-2006-STD-0127 COMMENT 39.2
Table 5.6.11 AHAM Dehumidifier Market Share Data Submittal for 54.01 to 74.99 

Pints/Day 

Efficiency Bin (liters/kWh) Market Share by Year (percent) 

2003 2004 2005 

< 1.50 3% 

1.50-1.54: Baseline = 1.50 9% 31% 

1.55-1.59: Mid Point = 1.55 75% 

1.60-1.64: EPACT 2005=1.60 76% 57% 

1.65-1.69: Suggested =1.65 22% 15% 12% 

1.70-1.79: Suggested = 1.70 

> 1.79: Max Available = 1.80 

< 1.50 3% 

AHAM also submitted incremental cost data by efficiency level for 3 dehumidifier 

capacity ranges as can be seen in Table 5.6.12, Table 5.6.13, and Table 5.6.14. The incremental 

cost at each level is the cost to upgrade a baseline-efficiency unit to that efficiency level. The 

average incremental costs shown in these tables are shipment-weighted averages. The cost 

information provided by AHAM does not account for the scheduled phase-out of 

hydrochlorofluorocarbon (HCFC) refrigerants due to the U.S. Environmental Protection Agency 

(EPA) regulations. R-22 is an HCFC refrigerant commonly used in dehumidifiers that will no 

longer be allowable for use in products manufactured starting in the year 2010. 

The first 2 product classes proposed by EPACT 2005, 25.00 pints/day or less and 25.01-

35.00 pints/day, were combined by AHAM because some manufacturers did not have shipments 

in the 25.01-35.00 pints/day category. To prevent disclosure of sensitive information, AHAM 

did not provide data for the EPACT 2005 product classes 45.01–54.00 pints/day and 75.00 

pints/day or greater because fewer than 3 manufacturers produce units in these categories. 

Also in Table 5.6.12 through Table 5.6.14, AHAM estimates the number of 

dehumidifiers shipped, by product class, that would be impacted by standards at each level. 

5-43 

EE-2006-STD-0127 COMMENT 39.2
Table 5.6.12 AHAM Dehumidifier Incremental Cost Data Submittal for 0–35.00 Pints/Day 

Product Class 0–35.00 pints/day 

Efficiency Level 1 2 3 4 5 

Energy Factor (EF) L/kWh 1.25 1.30 1.35 1.40 1.45 

Incremental Costs, $ Per 

Unit, Shipment-Weighted 

Average 3.12 4.92 10.41 18.8 25.61 

Minimum 0 0 8.03 15.2 21.9 

Maximum 7 10 20 29.54 34.79 

One-Time Product 

Conversion Expenses, 

Million $, Total for All 

Manufacturers 

R&D 0.05 0.15 2.25 4.75 7.15 

Marketing 0.1 0.15 1.7 4.75 6 

Conversion Capital 

Expenditure Assumptions, 

Million $, Total for All 

Manufacturers 

Building 0.025 5.05 5.1 5.15 5.2 

Tooling and 

Equipment 0.3 1.85 3.9 6.95 9 

Total Shipments, Thousands, subject to 

retooling, conversion, etc. as a function of 

minimum EF level revision 

525 625 745 745 745 

Table 5.6.13 AHAM Dehumidifier Incremental Cost Data Submittal for 35.01–45.00 Pints/Day 

Product Class 35.01–45.00 pints/day 

Efficiency Level 1 2 3 4 5 

Energy Factor (EF) L/kWh 1.35 1.40 1.45 1.50 1.74 

Incremental Costs, $ Per 

Unit, Shipment-Weighted 

Average 6.11 14.47 22.68 32.84 N/A 

Minimum 0 0 0 22.5 N/A 

Maximum 10 35.38 46.36 65.34 N/A 

One-Time Product 

Conversion Expenses, 

Million $, Total for All 

Manufacturers 

R&D 1.7 3.43 3.6 4.6 N/A 

Marketing 0.6 2.65 2.7 3.75 N/A 

Conversion Capital 

Expenditure Assumptions, 

Million $, Total for All 

Manufacturers 

Building 0.025 0.05 0.1 5.15 N/A 

Tooling and 

Equipment 2.45 4.5 4.55 8.65 N/A 

Total Shipments, Thousands, subject to 

retooling, conversion, etc. as a function of 

minimum EF level revision 

548 548 548 648 N/A 

5-44 

EE-2006-STD-0127 COMMENT 39.2
Table 5.6.14 AHAM Dehumidifier Incremental Cost Data Submittal for 54.01–74.99 Pints/Day 

Product Class 54.01–74.99 pints/day 

Efficiency Level 1 2 3 4 5 

Energy Factor (EF) L/kWh 1.55 1.60 1.65 1.70 1.80 

Incremental Costs, $ Per 

Unit, Shipment-Weighted 

Average 

Minimum 

Maximum 

4.18 

0 

13 

8 

0 

16 

12.36 

0 

19 

23.18 

9 

63 

33.94 

29 

87 

One-Time Product R&D 0.1 0.23 0.4 6.9 11.8 

Conversion Expenses, 

Million $, Total for All Marketing 0.1 0.15 0.2 6.35 11 

Manufacturers 

Conversion Capital Building 0.025 0.05 0.1 6.15 6.2 

Expenditure Assumptions, 

Million $, Total for All 

Manufacturers 

Tooling and 

Equipment 0.65 0.7 0.75 8.1 12 

Total Shipments, Thousands, subject to 

retooling, conversion, etc. as a function of 450 450 450 612 612 

minimum EF level revision 

Figure 5.6.10 plots the average incremental cost as a function of EF for the AHAM data. 

Note that the 3 curves have similar slopes. 

0 

5 

10 

15 

20 

25 

30 

35 

40 

Incremental Cost $ 

1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 

EF L/kWh 

0 - 35.00 pints/day 35.01 - 45.00 p nts/day i 54.01 - 74.99 pints/day 

Figure 5.6.10 AHAM Dehumidifier Cost-Efficiency Curves 

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EE-2006-STD-0127 COMMENT 39.2
5.6.2.2 Manufacturer Interviews 

DOE conducted interviews with dehumidifier manufacturers to develop a better 

understanding of the technologies used to improve dehumidifier energy efficiency. During these 

interviews, DOE asked manufacturers what groupings of design options would be required to 

increase the energy efficiency in order to meet the efficiency levels proposed in section 5.4.2 for 

dehumidifiers. The discussions helped DOE understand which design options have already been 

implemented and which additional design options DOE should consider. Additionally, the 

interviews provided DOE with a better understanding of the design strategies underlying the 

AHAM dehumidifier data submittal. The discussion below represents a consolidation of the 

responses. 

Components That Influence Energy Efficiency 

Manufacturers identified the components that influence energy efficiency, as measured 

by ANSI/AHAM Standard DH-1-2003, as fans and fan motors, heat exchanger coils, and 

compressors. Most manufacturers use either shaded-pole or permanent split-capacitor (PSC) fan 

motors. Some manufacturers have considered electronically-commutated motors (ECM), which 

use less energy than shaded-pole or PSC fan motors, but have not pursued implementation of 

them because of cost, availability, and concerns about service and reliability issues. 

Manufacturers also noted that the control system, either electronic or mechanical, does not 

influence energy efficiency under DOE test conditions. 

 Manufacturers currently use either rotary or reciprocating compressors in their 

dehumidifiers. The efficiency range of compressors available today varies by product class. 

Manufactures cited the energy efficiency ratio (EER) range for smaller-capacity product classes 

as 8 to 9 and 8.5 to 10.5 for larger-capacity product classes. Manufacturers have not 

implemented variable-speed compressors because of the higher cost and because the static 

conditions of the DOE test procedure cannot capture their benefits. Other compressor 

technologies, such as scroll or inertia compressors, are not available in capacities appropriate for 

dehumidifiers. 

Strategies to Increase Energy Efficiency 

Manufacturers consider material cost, shipping cost, and weight as key design 

parameters. Most manufacturers use only 1 or 2 product platforms for all of their product 

offerings. Manufacturers cited 2 strategies to increase energy efficiency: (1) heat exchanger coil 

improvements or (2) compressor improvements. Fan motors influence energy efficiency, but 

most manufacturers are already using the most efficient products available, with the exception of 

ECM. Coil improvements increase the amount of water collected per unit of energy consumed, 

but manufacturers stated that efficiency gains do not vary linearly with surface area growth. For 

example, an evaporator coil can only be grown so much for a given capacity and compressor 

before its coil surface will start to just cool the air rather than condense moisture out of it. 

Compressor improvements directly reduce energy usage. 

5-46 

EE-2006-STD-0127 COMMENT 39.2
Manufacturers cited compressors as the primary strategy to increase energy efficiency. 

Higher-capacity compressors usually offer higher efficiencies than lower-capacity units. As a 

result, a manufacturer may adapt a high-efficiency, high-capacity compressor to work in a 

higher-efficiency, lower-capacity dehumidifier. However, compressors are usually the most 

expensive dehumidifier component and any increases in compressor price will have a large 

impact on overall unit cost. 

Some manufacturers are currently using the most efficient compressors on the market and 

are therefore focusing on heat exchanger coil improvements to increase energy efficiency. Other 

manufacturers may focus on coil improvements because of the high costs for compressor 

improvements. For these manufacturers, further increases in efficiency are only possible via 

increasing the coil area or complete system redesigns. Complete system redesigns incur 

expenses for R&D, tooling expenditures, and building expenditures. Larger coils require more 

material, and manufacturers cited this as a concern, given high material prices. Also, as coils 

grow, the chassis and compressor capacity must grow as well. If the unit size increases past a 

certain point, fewer units can fit in a shipping container, which results in higher per-unit shipping 

costs. Also, as the chassis grows, weight increases, requiring more substantial packaging. 

Comparing costs required to increase efficiency across product classes, the higher the 

capacity, the higher the incremental costs due to the costs associated with the larger coil and 

compressor. 

5.6.2.3 Product Teardowns 

DOE tore down dehumidifiers to identify design options, and their associated costs, that 

can be used to raise EF. The dehumidifier teardown analysis performed for this engineering 

analysis included 14 teardown units in 4 product classes. DOE selected products such that 

within a product class, the models selected have the same capacity but different efficiencies. 

Figure 5.6.11 illustrates that the selected products cover the range of efficiency levels as 

provided by AHAM. Figure 5.6.11 also shows the efficiency range of products currently 

offered. Note that in the 35.01-45.00 pints/day product class, the range of product offerings 

extends beyond the range of the AHAM data, and DOE tore down a product near the high end of 

the commercially-available range. DOE does not explicitly identify the capacities of the units it 

tore down, because doing so could expose sensitive information about individual manufacturers’ 

products. 

AHAM did not provide data in the 45.01-54.00 pints/day product class to avoid 

disclosure of sensitive information, because fewer than 3 manufacturers produce units in these 

categories. Therefore, cost efficiency curves were only generated for the following product 

classes: 0 to 35.00 pints/day, 35.01 to 45.00 pints/day, and 54.01 to 74.99 pints/day. However, 

DOE conducted teardowns in the 45.01-54.00 pints/day product class for completeness. 

5-47 

EE-2006-STD-0127 COMMENT 39.2
2.2 

2 

1.8 

1.6 

1.4 

1.2 

1 

EF, L/kWh

Teardown Point 

Range of 

products 

Efficiency Range of 

AHAM data 

available 

35.00 pints/day 35.01-45.00 45.01-54.00 54.01-74.99 

or less pints/day pints/day pints/day 

Figure 5.6.11 Efficiency Range of Dehumidifier Teardowns 

After the dehumidifier teardowns, DOE grouped costs into the categories shown below. 

Figure 5.6.12 shows the breakdown of material costs for a typical baseline dehumidifier, as 

generated from DOE’s BOM. Note that the refrigeration system, heat exchangers, and fan 

components (components that largely determine energy consumption) make up 61 percent of the 

material costs. Figure 5.6.13 shows the various costs comprising a typical baseline 

dehumidifier’s full production cost. Depending on the manufacturer and the scale they are 

operating at, the depreciation costs may vary from those shown in Figure 5.6.13, which assumes 

a “green field” site. 

5-48 

EE-2006-STD-0127 COMMENT 39.2
Water Bucket Final 

2% 

Chassis 

17% 

1% 

Controls 

8% 

3% 

7% 

Condenser 

9% 

Assembly Boxing 

16% 

Fan Motor 

and Blade 

Wiring 

Harnesses 

Evaporator 

Refrigeration 

Circuit 

37% 

Figure 5.6.12 Baseline Dehumidifier Material Cost Distribution 

Space Tooling Depreciation Indirect 

4% 

2% 

Depreciation 

Cost 

1% 

Cost 

5% 

3% 

Raw 

Purchased Parts 

Assembly 

Labor Cost 

Fabrication 

Labor Cost 

Equipment 

Depreciation Cost 

0.1% 

Process 

Costs 

Material 

Costs 

32% 

Material Costs 

53% 

Figure 5.6.13 Baseline Dehumidifier Full Production Cost Distribution 

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EE-2006-STD-0127 COMMENT 39.2
Cost-Efficiency Curves 

To generate cost-efficiency curves, DOE focused on design options that influence EF. 

After the screening analysis, DOE retained the design options listed in Table 5.6.15. 

Table 5.6.15 Retained Design Options for Dehumidifiers 

1. Improved fan and fan-motor efficiency 

2. Improved compressor efficiency 

3. Improved evaporator performance 

4. Improved condenser performance 

Manufacturer interviews confirmed the validity of these design options, which can be 

classified into 2 categories: fan and fan-motor improvements and refrigeration component 

improvements. 

For fan and fan-motor improvements, the units DOE tore down contained only shaded 

pole and PSC motors. Manufacturer interviews confirmed that only these types of motors are 

currently incorporated in dehumidifiers. Some manufacturers have investigated upgrading to 

ECM designs, but have not performed these upgrades due to concerns over cost, availability, and 

reliability. 

For the refrigeration components, manufacturers cited 2 strategies to increase EF. The 

first approach is to use a higher-efficiency compressor. As the compressor efficiency increases, 

as measured by the compressor’s EER, the EF increases because less energy is required to 

remove water from the ambient air. Various types of losses can be reduced in order to increase 

compressor efficiency. For example, higher-efficiency motors reduce motor losses and resulting 

heat gain to the refrigerant. Improved compressor bearings can reduce mechanical losses, thus 

increasing mechanical efficiency. Reducing gas leakage from high-pressure to low-pressure 

regions through improved sealing techniques or tighter tolerances improves volumetric 

efficiency. Improved designs can also reduce pressure-drop losses in the compressor, as well as 

losses due to re-expansion of refrigerant or over- or under-compression. 

Available compressor efficiencies vary based upon compressor capacity range and 

technology. DOE’s product teardowns found different compressor technologies in different 

product classes. For the 0-35.00 pints/day product class, hermetic reciprocating compressors 

using R-134a refrigerant were prevalent. Units in the 35.01-45.00 pints/day product class used 

hermetic reciprocating or rotary compressors with R-22. Finally, the teardown units in the 

54.01-74.99 pints/day product class all used rotary compressors with R-22. 

To assess the impact of compressor EER on system EF, DOE assumed that the 

correlation between dehumidifier EF and compressor EER is approximately one-to-one. Given 

the lack of commercially-available software packages to simulate dehumidifiers, DOE verified 

this assumption by examining the DOE engineering analysis for residential room airconditioners.4

 The design of residential room air-conditioners is similar to that of dehumidifiers, 

but with a larger capacity. For the residential room air-conditioner engineering analysis, DOE 

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EE-2006-STD-0127 COMMENT 39.2
used the Oak Ridge National Laboratory (ORNL) Heat Pump Design Model to assess the impact 

of compressor efficiency increases. Using this model, DOE verified that the correlation between 

compressor EER and dehumidifier EF is indeed approximately one-to-one, meaning a one 

percent increase in compressor efficiency roughly translates to a one percent increase in system 

efficiency. 

To estimate the cost of compressor efficiency increases, DOE assumed a one-to-two 

relationship, meaning that a 1 percent increase in compressor efficiency requires a 2 percent 

increase in cost. Manufacturer interviews and discussions with compressor manufacturers 

verified this assumption. Table 5.6.16 shows DOE’s estimates for baseline compressor cost and 

efficiency. Table 5.6.17 lists other key estimates for the compressor portion of the engineering 

analysis. DOE determined, based on product teardowns, that manufacturers must use a 

reciprocating compressor to reach an EF of 1.5 in the 35.01-45.00 pints/day product class. 

Table 5.6.16 Assumed Dehumidifier Product-Class-Specific Cost and Efficiency 

Parameters 

Product 

Class 

Compressor 

Technology 

Refrigerant 

Baseline 

Compressor 

Cost, $ 

Baseline 

Compressor 

Capacity, 

Btud

/h 

Baseline 

Compressor 

EER, 

Btu/Wh 

Heat 

Exchanger 

Baseline 

Cost, $ 

0–35.00 

pints/day 

Hermetic 

Reciprocating R-134a $40 2800 7.60 $10 

35.01– 

45.00 

pints/day 

Rotary & 

Reciprocating R-22 $25 Rotary, $45 Recip. 4500 8.60 $12 

54.01– 

74.99 Rotary R-22 $30 6500 8.80 $15 

pints/day 

d

 Btu = British thermal units 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.6.17 Estimated Dehumidifier Cost and Efficiency Parameters for All Product 

Classes 

Assumption Value Source 

% Increase in compressor cost required to 

increase EER by 1% 2% Interviews with dehumidifier and 

compressor manufacturers 

% Increase in heat exchanger cost required to 

increase EF by 1% 1.71% Product teardowns 

% Increase in compressor EER required to 

increase EF by 1% 1.05% Analysis based on room airconditioner engineering analysis. 

% Increase in chassis and boxing cost per % 

increase in heat exchanger cost 1% DOE estimate 

Average chassis and boxing cost $21.00 Teardown analysis, manufacturer 

interviews 

% of selling price for overseas shipping 5% DOE estimate, verified by 

manufacturer interviews 

% of selling price for ground transportation 5% DOE estimate, verified by 

manufacturer interviews 

Manufacturers cited increasing heat exchanger area as a secondary option to raise EF via 

refrigeration components. In the units DOE tore down, DOE noted various options to increase 

heat exchanger surface area, including adding extra rows, increasing fin pitch, and increasing the 

overall heat exchanger face area. 

DOE developed general correlations for estimating cost impacts of heat exchanger 

improvements, fully recognizing that the relationship between heat exchanger design and 

dehumidifier performance is not linear. From product teardowns, DOE estimated that a 1 

percent increase in EF will increase heat exchanger costs by 1.7 percent, due to the higher 

materials costs required to achieve a larger surface area. From the product teardown analysis, 

DOE estimated typical baseline heat exchanger costs for each product class, as shown in Table 

5.6.16. Manufacturers noted that an increase in heat exchanger coil surface requires a 

corresponding increase in compressor capacity. DOE assumed a 1 percent increase in heat 

exchanger size requires a corresponding 1 percent increase in compressor capacity, where the 

baseline compressor capacities, also shown in Table 5.6.16, were developed from product 

teardowns. 

As heat exchanger surface area grows, the chassis and packaging must grow as well. 

DOE estimates that a 1 percent increase in heat exchanger cost results in a 1 percent increase in 

chassis and packaging costs, because the heat exchanger size is increased. From product 

teardowns, DOE calculated an average baseline chassis and boxing cost of $21.00 for all product 

classes. DOE assumed a constant chassis and packaging cost across all product classes based 

upon manufacturers’ comments that many manufacturers use the same platform for all product 

classes. 

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EE-2006-STD-0127 COMMENT 39.2
According to manufacturers, a key dehumidifier design parameter is shipping cost. 

Dehumidifiers are sized to maximize the number of units that can fit in a standard shipping 

container. A possible consequence of increasing heat exchanger size – and subsequently chassis 

and package size – is a decrease in the number of units per container and therefore an increase in 

shipping costs per unit. Based upon manufacturer interviews and DOE’s experience, shipping 

costs and freight costs are estimated as 5 percent of the selling price. This percentage has 

traditionally been estimated as 3 percent to 4 percent, but recent increases in fuel costs have 

increased transportation costs. To account for domestic versus overseas manufacturing, DOE 

used market data to develop location-weighted shipping costs. DOE then scaled shipping costs 

based upon incremental increases in selling price. 

For non-manufacturing costs (i.e., building, tooling/equipment, R&D, and marketing), 

DOE used the costs submitted by AHAM with a 10-year depreciation period for building costs 

and a 3-year depreciation period for the other costs. Figure 5.6.14 through Figure 5.6.19 

compare DOE’s cost estimates to the AHAM-submitted data. These figures demonstrate 

reasonable agreement between the DOE and AHAM cost-efficiency curves in all product classes. Incremental Production Costs, $ 

16 

14 

12 

10 

8 

6 

4 

2 

0 

1.2 1.25 1.3 1.35 1.4 1.45 1.5 

EF, L/kWh 

DOE AHAM Average

AHAM Mi AHAM M 

Figure 5.6.14 Comparison of Dehumidifier Incremental Production 

Costs: 0-35.00 Pints/Day 

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EE-2006-STD-0127 COMMENT 39.2
0 

5 

10 

15 

20 

25 

30 

35 

Incremental Production Costs, $ 

1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 

EF, L/kWh 

DOE AHAM Average 

Figure 5.6.15 Comparison of Incremental Dehumidifier Production 

Costs: 35.01-45.00 Pints/Day 

0 

2 

4 

6 

8 

10 

12 

14 

16 

18 

Incremental Production Costs, $ 

1.5 1.55 1.6 1.65 1.7 1.75 1.8 1.85 

EF, L/kWh 

DOE AHAM Average 

Figure 5.6.16 Comparison of Incremental Dehumidifier Production 

Costs: 54.01-74.99 Pints/Day 

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EE-2006-STD-0127 COMMENT 39.2
0 

5 

10 

15 

20 

25 

30 

35 

40 

Incremental Production Costs, $ 

1.2 1.25 1.3 1.35 1.4 1.45 1.5 

EF, L/kWh 

DOE AHAM Average AHAM Min AHAM Max 

Figure 5.6.17 Comparison of Total Incremental Dehumidifier Costs: 

0-35.00 Pints/Day 

0 

10 

20 

30 

40 

50 

60 

70 

Incremental Production Costs, $ 

1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 

EF, L/kWh 

DOE AHAM Average AHAM Min AHAM Max 

Figure 5.6.18 Comparison of Total Incremental Dehumidifier Costs: 

35.01-45.00 Pints/Day 

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EE-2006-STD-0127 COMMENT 39.2
0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 

Incremental Production Costs, $ 

1.5 1.55 1.6 1.65 1.7 1.75 1.8 1.85 

EF, L/kWh 

DOE AHAM Average AHAM - Min AHAM - Max 

Figure 5.6.19 Comparison of Total Incremental Dehumidifier Costs: 

54.01-74.99 Pints/Day 

Table 5.6.18 tabulates DOE’s incremental production cost against the AHAM data 

submittal. The AHAM data is shown disaggregated into shipment-weighted incremental 

production costs as well as non-manufacturing cost components. This comparison validates the 

AHAM average total incremental manufacturing costs, which are used to define the costefficiency relationship for the LCC analysis. In the single instance where AHAM did not 

provide data (EF = 1.74 for the 35.01 to 45.01 pints/day product class), the total incremental 

manufacturing cost is extrapolated from a linear fit of the AHAM data at lower efficiency levels. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.6.18 Incremental Costs to Increase Dehumidifier EF 

Product 

Class, 

pints/day 

EF, 

L/kWh 

DOE 

Incremental 

Production 

Cost, $ per 

unit 

AHAM 

Incremental 

ShipmentWeighted 

Production 

Cost, $ per unit 

Incremental 

Depreciated 

Cost, $ per 

unit 

Incremental 

R&D and 

Marketing 

Costs, $ per 

unit 

Total 

Incremental 

Manufacturing 

Cost, $ per unit 

1.25 2.56 2.83 0.20 0.10 3.12 

1.3 5.35 2.97 1.79 0.16 4.92 

0-35.00 1.35 8.12 6.21 2.43 1.77 10.41 

1.4 11.04 10.75 3.80 4.25 18.80 

1.45 14.00 15.00 4.72 5.88 25.61 

1.35 2.61 3.22 1.49 1.40 6.11 

35.01-

45.00 

1.4 5.28 8.03 2.75 3.70 14.47 

1.45 7.75 16.06 2.79 3.83 22.68 

1.5 22.41 23.30 5.24 4.30 32.84 

1.74 N/A N/A N/A N/A 74.72* 

1.55 2.37 3.54 0.49 0.15 4.18 

54.01-

74.99 

1.6 4.77 7.19 0.53 0.28 8.00 

1.65 7.32 11.34 0.58 0.44 12.36 

1.7 10.23 10.55 5.42 7.22 23.18 

1.8 15.40 13.97 7.55 12.42 33.94 

* Extrapolated from the AHAM cost-efficiency curve. 

5.6.3 Cooking Products 

5.6.3.1 AHAM Data 

Conventional Cooking Products 

In concurrence with various stakeholders, DOE determined that the efficiency 

characteristics of gas and electric cooktops and ovens from the 1996 TSD were still valid. 

Therefore, the efficiency data provided in the 1996 TSD were presumed to still be valid. 

Furthermore, DOE believes that the cost of the design options investigated in the 1996 TSD are 

also valid once adjusted to reflect changes in the producer price index (PPI). The data from the 

1996 TSD are detailed in section 5.6.3.2. 

Microwave Ovens 

In contrast to conventional cooking products, microwave ovens were presumed to have 

incorporated improved technology since 1996. Therefore, AHAM provided data on microwave 

oven efficiency and microwave standby power for a sample of microwave ovens currently 

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EE-2006-STD-0127 COMMENT 39.2
available in the U.S. market.5

 Microwave oven efficiency was tested according to DOE’s test 

procedure, which utilizes International Electrotechnical Commission (IEC) 705-1988 and 

Amendment 2-1993, Methods for measuring the performance of microwave ovens for household 

and similar purposes. Standby power was tested in accordance with IEC 62301-2005, 

Household electrical appliances – Measurement of standby power. 

The microwave oven test procedure specified in IEC 705-1998 and Amendment 2-1993 

calls for heating a glass container containing one liter of water at full power until the water 

temperature is raised by a specified amount. The starting temperature of the water T1 in degrees 

Celsius (°C) is given as: 

T1 = T0 – (10 ± 1 °C) where, 

T0 = the ambient temperature, specified as 20 ± 2 °C 

The water is heated by the operation of the microwave oven until the final water 

temperature T2 in °C is: 

T2 = T0 ± 1 °C 

The microwave power output P in watts (W) is then calculated from: 

P = (4.187 mw (T2 – T1) + 0.88 mc (T2 – T0))/t where, 

m

mw = the mass of the water in grams (g) 

c = the mass of the container in g 

t = the heating time in seconds (s) 

The time to heat the water load, power input PIN in W, and the total energy consumption 

EM in watt-hours (Wh) of the microwave oven during the test period are also recorded. This test 

is repeated 3 times, unless the power output value resulting from the second test is within 1.5 

percent of the value obtained from the first test. The 2 or 3 values of P are averaged for further 

calculations. 

Cooking efficiency EffMO is then obtained using: 

EffMO = P/PIN 

For the remainder of the calculations, the test procedure specified in 10 CFR 430 Subpart 

B Appendix I is utilized. Note that in the following calculations, all temperatures are expressed 

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EE-2006-STD-0127 COMMENT 39.2
in degrees Fahrenheit. The microwave oven test energy output ET in Wh (kilo-joules (kJ))e

 is 

calculated as: 

ET = CPMW (T2 – T1) + CCMC (T2 – T0))/Ke where, 

MW = the measured mass of the test water load in pounds (lb), (g) 

MC = the measured mass of the test container before filling with test water load in lb (g) 

T1 = the initial test water load temperature in °F (°C) 

T2 = the final test water load temperature in °F (°C) 

T0 = the measured ambient room temperature in °F (°C) 

CC = 0.210 Btu/lb-°F (0.88 kJ/kilogram (kg)-°C), specific heat of the test container 

CP = 1.0 Btu/lb-°F (4.187 kJ/kg-°C), specific heat of water 

Ke = 3,412 Btu/kWh (3,600 kJ/kWh), conversion factor of kWh to Btu. 

The 2 or 3 values for test energy output are averaged and the microwave oven annual 

energy consumption EMO is calculated in kWh per year from: 

EMO = (EM x OM)/ET where, 

EM = the test energy consumption in Wh (kJ) 

OM = 79.8 kWh (287,280 kJ) per year, the microwave oven annual useful cooking-energy 

output 

Finally, the microwave oven energy factor RMO (equivalent to EF) is calculated from: 

RMO = OM/EMO 

EF is the metric for microwave ovens on which the DOE efficiency standard is based, 

while AHAM provided test data in terms of cooking efficiency in their data submittal for this 

rulemaking. From the above equations, it can be observed that there are several contributing 

factors that can lead to significant test-to-test variations in measured EF and efficiency. First, the 

tolerances on the temperature specifications are substantial relative to the absolute values. The 

range of allowable temperatures for ambient, starting, and final temperatures can lead to 

acceptable test load temperature rises ranging from 4 to 16 °C. Since the heating time is on the 

order of only a few tens of seconds, power and energy output calculations are difficult to 

measure consistently test-to-test. In addition, the efficiency calculation assumes that input power 

is constant for the duration of the test, which may not be the case. These factors make the 

existing test procedure difficult to conduct with accuracy and repeatability. 

e

 Note that in order to correctly utilize the equation as specified in the test procedure to produce either watt-hours for 

standard units or kJ for metric units, additional factors must be applied. For standard units, ET must be multiplied by 

1000. For metric units, ET must be divided by 3600. 

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EE-2006-STD-0127 COMMENT 39.2
In the recent testing for this analysis, although AHAM only tested 21 units from 9 

manufacturers, the units were selected to represent a broad spectrum of models available in the 

marketplace with varying capacities and features. Figure 5.6.20 through Figure 5.6.22 display 

the AHAM microwave oven efficiency and standby power data. 

50% 

55% 

60% 

65% 

Efficiency 

600 700 800 900 1000 1100 1200 1300 1400 

Rated Output Power (W) 

Figure 5.6.20 AHAM Microwave Oven Efficiency versus Rated 

Output Power6 

Figure 5.6.20 illustrates a small variation in efficiency across all rated output powers, 

approximately ±3.5 absolute percentage points from the average efficiency. There is a lack of a 

correlation between microwave oven rated output power and microwave oven efficiency. Figure 

5.6.21 illustrates the relationship between microwave oven efficiency and microwave oven 

volume. Similarly, there is no correlation between microwave oven efficiency and volume. 

Figure 5.6.20 and Figure 5.6.21 confirm DOE’s approach of creating a single product class for 

microwave ovens irrespective of rated output power or cavity volume, and demonstrate that there 

is no basis to specify an efficiency standard that is a function of either rated output power or 

cavity volume. 

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EE-2006-STD-0127 COMMENT 39.2
50% 

55% 

60% 

65% 

Efficiency 

0.0 0.5 1.0 1.5 2.0 2.5 

Microwave Oven Volume (ft^3) 

Figure 5.6.21 AHAM Microwave Oven Efficiency versus Oven Volume7 

Microwave oven standby power consumption is a function primarily of the digital clock 

display, with more complex graphical displays drawing more power. According to AHAM, the 

3 major types of displays used in microwave ovens are light emitting diodes (LEDs), vacuum 

fluorescent display (VFD), and liquid crystal display (LCD). Typically, LCD without backlighting uses the least amount of energy while VFD uses the most. Energy consumed by LCD 

would depend on whether back-lighting is present or not, and if present, the number of LEDs 

used for back-lighting. For LEDs, the number of segments, color and operating temperature has 

an impact on energy consumption. The size of the display (number of digits and icons) also 

affects the energy consumed by the display. For VFD, the size of the display is a major factor in 

energy consumption.8

 Standby power consumption may also be affected by the electronic 

controls required for features such as cooking sensors. 

Figure 5.6.22 displays AHAM-measured microwave oven standby-power-consumption 

data as a function of rated output power. Unlike efficiency, these data show a wide range of 

standby power usage, but there is no correlation between standby power consumption and output 

power. Standby power consumption ranged from 1.5 to 5.8 W, with 9 of the 21 microwave 

ovens meeting the FEMP recommendation of 2.0 W or less. The average standby power 

measured was 2.9 W. AHAM did not provide any information with which DOE could correlate 

standby power with other features such as cooking sensors. 

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EE-2006-STD-0127 COMMENT 39.2
7.0 

6.0 

Standby Power Consumption (W) 5.0 

4.0 

3.0 

2.0 

1.0 

0.0 

600 700 800 900 1000 1100 1200 1300 1400 

Rated Output Power (W) 

Figure 5.6.22 AHAM Microwave Oven Standby Power Consumption9 

Table 5.6.19 compares the AHAM-measured microwave oven standby-powerconsumption data with data from other studies that have examined standby power in the U.S. and 

Canada. It can be seen that average standby power has remained relatively constant since 1997 

even though minimum and maximum levels have varied by a greater amount. 

Table 5.6.19 Microwave Oven Standby Power Comparison 

Source 

Microwave Oven Standby Power Consumption 

Min, W Average, 

W Max, W Std Dev, W # Samples 

AHAM 200610 1.5 2.9 5.8 0.8 21 

CBEEDAC 200611 0.4 1.9 3.3 0.8 19 

CREEDAC 2001 (New Stock)12 0.8 3.8 12.6 - 4 

CREEDAC 2001 (Existing Stock)13 0.0 2.1 7.3 - 64 

LBNL 199914 0.0 2.9 6.0 - 42 

Florida Solar Energy Center 199815 - 3.0 - - 25 

LBNL 199716 - 3.1 - - -

Although the DOE test procedure does not measure standby power, it is recognized that 

annual energy consumption can be significantly affected by standby power in real-world usage. 

For example, a 1-watt increase in standby power corresponds to an increase of 8.76 kWh in 

annual energy consumption. The microwave oven test procedure assumes an annual useful 

cooking energy output (OM) of 79.8 kWh. For a baseline microwave oven that operates at 55.7 

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EE-2006-STD-0127 COMMENT 39.2
percent efficiency (ET/EM), annual energy consumption (EMO) not including standby power 

would be: 

EMO = OM/(ET/EM) = 143.3 kWh 

Therefore each watt of standby power included in the annual energy consumption metric 

would increase it by 6 percent for a baseline microwave oven. Since the highest measured 

standby power was 5.8 W, the increment of 3.8 W over the FEMP recommended level of 2.0 W 

would represent a 23 percent increase in annual energy consumption for a baseline microwave 

oven. Since the annual energy consumption of a more efficient unit will be lower, the standby 

power will have an even greater relative contribution for high-efficiency microwave ovens. 

5.6.3.2 Review of Past TSDs 

After consulting with AHAM and various stakeholders, DOE determined that the design 

options for cooking products other than microwaves have not changed significantly since the 

1996 TSD analysis. Therefore, DOE decided to update the 1996 TSD analysis using the PPI to 

scale incremental manufacturing cost data for gas and electric cooktops, and gas and electric 

standard and self-cleaning ovens. For gas cooktops and ovens, the PPI for gas household 

cooking equipment was utilized. Similarly, the PPI for electric household cooking equipment 

was used for electric cooktops and ovens. Where additional design options have been identified 

that weren’t in the 1996 TSD, DOE is soliciting inputs from stakeholders to determine efficiency 

and incremental cost information. This cost-efficiency data will be included in the TSD for the 

NOPR. 

Comparison of current microwave oven efficiency data with analogous data from the 

1996 TSD showed that the range of efficiency levels analyzed in the 1996 TSD are still valid, 

although AHAM indicated in comments provided along with its data submittal for this 

rulemaking that certain design options used to achieve those levels have already been 

optimized.17 But as noted in section 5.4.2, the range of efficiency levels from the 1996 TSD is 

still representative of the performance of current microwave oven models. Therefore, for the 

purposes of this analysis, the same efficiency levels are used. As with the conventional cooking 

products, the incremental manufacturing cost data from the 1996 TSD was scaled by the PPI for 

electric household cooking equipment, which includes microwave ovens, to obtain the costefficiency relationship. DOE is seeking further information from stakeholders regarding specific 

design options and cost increments to include in the TSD for the NOPR. 

Cooktop Test Procedure 

DOE’s cooktop test procedure is based on measuring the amount of energy required to 

raise an aluminum block test load from room temperature to a specified temperature above room 

temperature at full input heating rate, then operating the burner or element a fixed time longer at 

a reduced input heating rate. The size of the test block depends on the burner or element size, and 

the test is repeated for each burner or element. Annual energy consumption is calculated from the 

average cooking efficiency of the burners or elements. Cooktops are rated using EF, which is the 

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EE-2006-STD-0127 COMMENT 39.2
ratio of the annual useful cooking-energy output of the cooktop to its total annual energy 

consumption. The annual energy consumption includes the energy input during the time the load 

is being heated, plus the energy consumed by any standing pilot during standby hours for a gas 

cooktop. Therefore, design options that raise the cooking efficiency of a gas or electric cooktop 

and/or reduce the energy consumption of a pilot on a gas cooktop can decrease the total annual 

energy consumption and therefore improve EF. 

Gas Cooktops 

Table 5.6.20 describes the design options and design option combinations that result in 

increased EF of gas cooktops. The design options and efficiency levels analyzed are those 

presented in the 1996 engineering analysis, with several design options (reflective surfaces and 

thermostatically-controlled burners) eliminated in this analysis as described in section 5.4.2. 

Table 5.6.20 Gas Cooktop Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 39.9% 0.156 -

1 Baseline + Electronic Ignition 39.9% 0.399 $12.06 

2 1 + Sealed Burners 41.8% 0.420 $32.06 

Notes: 

Baseline: Cooktop cooking efficiency = 39.9%, four conventional 9,000 Btu/hr burners, two 117 Btu/hr standing

pilot lights 

(1) Electronic Ignition: Standing pilot lights eliminated, cooking efficiency increase = 0.0% 

(2) Sealed Burners: Cooking efficiency increase = 4.8% (relative percent) 

Electric Coil Cooktops 

Table 5.6.21 describes the design option that results in increased cooking efficiency of 

electric open (coil) cooktops. The design option and efficiency levels analyzed are those 

presented in the 1996 engineering analysis, with one design option (reflective surfaces) 

eliminated in this analysis as described in section 5.4.2. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.6.21 Electric Coil Cooktop Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 73.7% 0.737 -

1 Baseline + Improved Contact 

Conductance 76.9% 0.769 $2.28 

Notes: 

Baseline: Cooktop cooking efficiency = 73.7%, two 6-inch 1,250 W and two 8-inch 2,100 W elements

(1) Improved Contact Conductance: Cooking efficiency increase = 4.3% (relative percent) 

Electric Smooth Cooktops 

Table 5.6.22 describes the design options that result in increased cooking efficiency of 

electric smooth cooktops. The design options and efficiency levels analyzed are those presented 

in the 1996 engineering analysis, with one design option (induction element) eliminated in this 

analysis as described in section 5.4.2. Another design option (radiant element) discussed in the 

1996 engineering analysis was not included in this analysis because it exhibited a lower 

efficiency than the baseline cooktop. 

Table 5.6.22 Electric Smooth Cooktop Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 74.2% 0.742 -

1 Baseline + Halogen Lamp 

Element 75.3% 0.753 $89.09 

Notes: 

Baseline: Cooktop cooking efficiency = 74.2%, two 6-inch 1,500 W and two 8-inch 2,000 W solid disk elements

(1) Halogen Element: Cooking efficiency increase = 1.5% (relative percent), two small 1,200 W and two large 

1,800 W circular lamps 

Conventional Oven Test Procedure 

DOE’s oven test procedure is based on measuring the amount of energy required to raise 

an aluminum block test load from room temperature to a specified temperature above room 

temperature. Ovens are rated using EF, which is the ratio of the annual useful cooking-energy 

output of the oven (energy conveyed to the item being heated) to its total annual energy 

consumption. The annual energy consumption includes the energy input during the time the load 

is being heated plus the energy consumed by other features such as a clock, standing pilot, 

electronic ignition system, and/or self-cleaning cycles. Therefore, design options that raise the 

cooking efficiency of the oven and/or reduce the energy consumption of features not related to 

heating food can decrease the total annual energy consumption and therefore improve EF. 

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EE-2006-STD-0127 COMMENT 39.2
Gas Ovens 

Table 5.6.23 describes the design options and design option combinations that result in 

increased EF of gas standard ovens. The design options and efficiency levels analyzed are those 

presented in the 1996 engineering analysis, with one design option (oven separator) eliminated in 

this analysis as described in section 5.4.2. For the NOPR, DOE intends to analyze additional 

design options which would result in a lowering of the energy consumption of non-cooking 

features (e.g. standby power). 

Table 5.6.23 Gas Standard Oven Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 5.9% 0.0298 -

1 Baseline + Electric Glo-bar 

Ignition 5.8% 0.0536 $12.06 

2 1 + Improved Insulation 6.1% 0.0566 $15.64 

3 2 + Improved Door Seals 6.2% 0.0572 $16.72 

4 3 + Forced Convection 6.5% 0.0593 $38.86 

5 4 + Reduced Vent Rate 6.5% 0.0596 $40.48 

6 5+ Reduced Conduction Losses 6.6% 0.0600 $44.11 

1a Baseline + Electronic Spark 

Ignition 5.8% 0.0583 $15.00 

Notes: 

Baseline: Cooking efficiency = 5.92%, 2” of 1.09 lb/cubic foot insulation, standing pilot light ignition = 175

Btu/hr 

(1) Baseline + Electric Glo-Bar Ignition: Cooking efficiency decrease = 0.152 (absolute percentage points), added 

electricity consumption = 176 Wh 

(2) 1 + Improved Insulation: Cooking efficiency increase = 4.9% (relative percent) 

(3) 2 + Improved Door Seals: Cooking efficiency increase = 1.0% (relative percent) 

(4) 3 + Forced Convection: Cooking efficiency increase = 4.8% (relative percent), added electricity consumption 

= 15 watt-hours 

(5) 4 + Reduced Vent Rate: Cooking efficiency increase = 0.5% (relative percent) 

(6) 5 + Reduced Conduction Losses: Cooking efficiency increase = 0.05 (absolute percentage points) 

(1a) Baseline + Electronic Spark Ignition: Cooking efficiency decrease = 0.09 (absolute percentage points), 

added electricity consumption = 0.0 Wh. Standard levels 1 and 1a correspond to designs that are utilized for the 

same purpose--eliminate the need for a standing pilot--but the technologies for each design are different. 

 Standard level 1 is a hot surface ignition device while standard level 1a is a spark ignition device 

Table 5.6.24 describes the design options and design option combinations that result in 

increased EF of gas self-clean ovens. The design options and efficiency levels analyzed are 

those presented in the 1996 engineering analysis, with one design option (oven separator) 

eliminated in this analysis as described in section 5.4.2. For the NOPR, DOE intends to analyze 

additional design options which would result in a lowering of the energy consumption of noncooking features (e.g. standby power). 

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Table 5.6.24 Gas Self-Cleaning Oven Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 7.1% 0.0540 -

1 Baseline + Forced Convection 8.8% 0.0625 $11.01 

2 1 + Reduced Conduction Losses 8.8% 0.0627 $15.38 

3 2 + Improved Door Seals 8.9% 0.0632 $16.60 

Notes: 

Baseline: Cooking efficiency = 7.13%, clock power = 3.6 W, 2” of 1.90lb/cubic foot insulation, electronic 

ignition = 176 Wh, self-cleaning energy consumption = 43,158 Btu

(1) Baseline + Forced Convection: Cooking efficiency increase = 23% (relative percent), added electricity 

consumption (during cooking and cleaning cycles) = 15 Wh 

(2) 1 + Reduced Conduction Losses: Cooking efficiency increase = 0.05 (absolute percentage points) 

(3) 2 + Improved Door Seals: Cooking efficiency increase = 1.0% (relative percent) 

Electric Ovens 

Table 5.6.25 describes the design options and design option combinations that result in 

increased EF of electric standard ovens. The design options and efficiency levels analyzed are 

those presented in the 1996 engineering analysis, with several design options (bi-radiant oven 

and oven separator) eliminated in this analysis as described in section 5.4.2. For the NOPR, 

DOE intends to analyze additional design options which would result in a lowering of the energy 

consumption of non-cooking features (e.g. standby power). 

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Table 5.6.25 Electric Standard Oven Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 12.2% 0.1066 -

1 Baseline + Reduced Vent Rate 12.8% 0.1113 $1.63 

2 1 + Improved Insulation 13.4% 0.1163 $4.84 

3 2 + Improved Door Seals 13.7% 0.1181 $8.53 

4 3 + Forced Convection 14.0% 0.1206 $48.14 

5 4 + Reduced Conduction Losses 14.1% 0.1209 $51.69 

Notes: 

Baseline: Cooking efficiency = 12.15%, clock power = 3.9 W, 2” of 1.09 lb/cubic foot insulation 

(1) Baseline + Reduced Vent Rate: Cooking efficiency increase = 0.62% (absolute percentage points) 

(2) 1 + Improved Insulation: Cooking efficiency increase = 0.52% (relative percent) 

(3) 2 + Improved Door Seals: Cooking efficiency increase = 0.24 (absolute percentage points) 

(4) 3 + Forced Convection: Cooking efficiency increase = 0.33 (absolute percentage points), added electricity 

consumption = 15 Wh 

(5) 4 + Reduced Conduction Losses: Cooking efficiency increase = 0.05 (absolute percentage points) 

Table 5.6.26 describes the design options and design option combinations that result in 

increased EF of electric self-cleaning ovens. The design options and efficiency levels analyzed 

are those presented in the 1996 engineering analysis, with several design options (bi-radiant oven 

and oven separator) eliminated in this analysis as described in section 5.4.2. For the NOPR, 

DOE intends to analyze additional design options which would result in a lowering of the energy 

consumption of non-cooking features (e.g. standby power). 

Table 5.6.26 Electric Self-Cleaning Oven Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 13.8% 0.1099 -

1 Baseline + Reduced 

Conduction Losses 13.8% 0.1102 $4.37 

2 1 + Forced Convection 14.2% 0.1123 $43.98 

Notes: 

Baseline: Cooking efficiency = 13.79%, clock power = 3.8 W, 2” of 1.09 lb/cubic foot insulation, self-cleaning

energy consumption = 5,286 Wh 

(1) Baseline + Reduced Conduction Losses: Cooking efficiency increase = 0.05 (absolute percentage points) 

(2) 1 + Forced Convection: Cooking efficiency increase = 0.33 (absolute percentage points), added electricity 

consumption = 15 Wh 

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EE-2006-STD-0127 COMMENT 39.2
Conventional Oven Energy Use versus Volume 

The oven cost-efficiency relationships detailed above are predicated upon baseline ovens 

with a cavity volume of 3.9 cubic feet. It is well documented, however, that efficiency scales 

with oven cavity volume. This variation between efficiency, and thus energy factor, and oven 

volume results from the fact that larger ovens have higher thermal masses and larger vent rates 

than smaller ovens. Since the test procedure for establishing EF is a transient test with a fixed 

test load, the increased energy consumption due to the increased mass of larger units yields a 

lower EF. The 1980 DOE engineering analysis for residential appliances18 established a 

relationship between oven volume and EF from data compiled by the National Bureau of 

Standards (which was renamed to National Institute of Standards and Technology). Using these 

data, linear equations were derived for both electric and gas ovens. No distinction was found to 

exist between standard and self-cleaning ovens for either gas or electric ovens. Intercepts for a 

particular baseline model or oven design were chosen so that the equations pass through the 

desired EF corresponding to a particular volume. Values from the 1996 TSD for the slopes and 

intercepts for gas and electric ovens are listed in Table 5.6.27. The 1996 TSD did not analyze 

data at every efficiency level, and higher efficiency levels are not included in Table 5.6.27 

because certain design options have been eliminated in the current analysis. DOE believes the 

slopes and intercepts of these equations from the 1996 TSD to still be valid. 

Table 5.6.27 Slopes and Intercepts for Oven Energy Factor versus Cavity Volume 

Relationship 

Energy 

Efficiency 

Electric Gas 

Slope = -0.0157 Slope = -0.0073 

Level Standard Self-Clean Standard Self-Clean 

Baseline - 0.1632 0.0865 0.0865 

1 0.1752 - 0.0895 -

2 0.1802 - - -

3 0.1822 - 0.0935 -

Note: EF = (Slope x Volume) + Intercept where Volume is expressed in cubic feet. 

Microwave Ovens 

Table 5.6.28 describes the design options and design option combinations that result in 

increased EF of microwave ovens. The design options and efficiency levels analyzed are those 

presented in the 1996 engineering analysis, with incremental manufacturing costs scaled by the 

PPI for electric household cooking equipment. For the NOPR, DOE seeks input from 

stakeholders on the approach of analyzing additional design options which would result in a 

lowering of the energy consumption of non-cooking features (e.g. standby power), even though 

the test procedure currently does not account for such usage in EF. It should be noted that DOE 

is considering the addition of standby power measurement to the test procedure. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.6.28 Microwave Oven Manufacturing Cost and Efficiency Increments 

Level Efficiency Level Description Cooking 

Efficiency EF 

Delta Manufacturer 

Cost from Baseline, 

2006 dollars 

Baseline Baseline 55.7% 0.557 -

1 Baseline + More Efficient 

Power Supply 58.6% 0.586 $8.68 

2 1 + More Efficient Fan 58.8% 0.588 $17.95 

3 2 + More Efficient Magnetron 59.7% 0.597 $32.53 

4 3 + Reflective Surfaces 60.2% 0.602 $51.11 

Notes: 

Baseline: Cooking efficiency = 55.7% 

(1) Efficient Power Source: Cooking efficiency increase = 2.9 (absolute percentage points) 

(2) Efficient Fan: Cooking efficiency increase = 0.23 (absolute percentage points) 

(3) Efficient Magnetron: Cooking efficiency increase = 0.90 (absolute percentage points) 

(4) Reflective Surface: Cooking efficiency increase = 0.50 (absolute percentage points) 

5.6.4 Commercial Clothes Washers 

5.6.4.1 AHAM Data 

In support of DOE in the commercial clothes washer rulemaking, AHAM collected 

incremental manufacturing cost data from its member companies in October of 2006. Table 

5.6.29 compiles unit shipment and energy-efficiency data for commercial clothes washers from 

2002 to 2005. 

Table 5.6.29 AHAM Commercial Clothes Washer Shipments and Shipment-Weighted 

MEF and WF Data Submittal 

Year Total Shipments MEF (ft3

/kWh) WF 

(Gallons / ft3) 

2002 175,187 1.30 11.77 

2003 190,720 1.33 11.42 

2004 178,382 1.33 11.33 

2005 177,394 1.41 10.91 

Table 5.6.30 reproduces AHAM's 2006 data submittal for the average water and power 

consumption agitator vertical-axis commercial clothes washers that meet the baseline 1.26 MEF 

energy efficiency level. Since January 2007, however, clothes washers manufactured at this 

baseline 1.26 MEF must meet a lower WF (9.5) than the one listed in the AHAM data submittal. 

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EE-2006-STD-0127 COMMENT 39.2
Table 5.6.30 AHAM Baseline MEF Commercial Clothes Washer Average Energy and 

Water Use Data Submittal 

Attributes of Average 1.26 MEF Washer Power Consumption 

per Wash Cycle (kWh) 

MEF 

(ft3

/kWh) 

WF 

(Gallons 

/ ft3

) 

Washer 

Capacity 

(ft3) 

Water Use 

(Gallons/Cycle) 

Standby 

Power 

Consumption 

(W) 

Hot 

Water 

Machine 

Power 

Dryer 

Power 

1.26 11.1 3.1 34.3 * 0.87 0.18 1.38 

DOE requested incremental cost data for efficiency levels discussed in sections 5.4.1 and 

5.4.2. Additional data submitted by AHAM, shown in Table 5.6.31, represents aggregated input 

from the producers of commercial clothes washers sold in the U.S. The shipment-weighted 

incremental cost at each level is the cost to upgrade the baseline efficiency machine (1.26 

MEF/9.5 WF) to that efficiency level. Many efficiency levels contain no cost data since AHAM 

requires a minimum of 3 data points per efficiency level before submitting shipment-weighted 

results. 

Table 5.6.31 AHAM Commercial Clothes Washer Incremental Cost Data Submittal 

Efficiency Level 1 2 3 4 5 6 

Exploratory MEF Levels – 

Commercial Clothes Washers 1.42 1.6 1.72 1.8 2 2.2 

Exploratory WF Levels – 

Commercial Clothes Washers 9.5 8.5 8.0 7.5 5.5 5.1 

Incremental Costs ($ Per Unit) – 

Shipment-Weighted $ 74.73 * * * $ 316.35 * 

* Insufficient data reported 

Table 5.6.31 displays the AHAM commercial clothes washer cost submittal. For 2 

proposed efficiency levels, the MEF, WF, and incremental manufacturing cost are noted. There 

were insufficient data at other efficiency levels to report costs. Figure 5.6.23 plots the efficiency 

levels for which AHAM submitted incremental manufacturing cost data, i.e. the baseline 

efficiency level, efficiency level 1, and efficiency level 5. 

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EE-2006-STD-0127 COMMENT 39.2
350 

300 

Incremental Mfg. Cost ($/unit) 250 

200 

150 

100 

50 

0 

liBase ne EL: 

9.5WF 

EL 1: 9.5WF 

EL 5: 5.5WF 

1.2 1.4 1.6 1.8 2 2.2 

MEF EL = Efficiency Level 

Figure 5.6.23 AHAM Commercial Clothes Washer Incremental 

Cost Data Submittal 

Manufacturers stated that the baseline efficiency level (1.26 MEF/9.5 WF) and the 

efficiency level 1 (1.42 MEF/9.5WF) are attainable with agitator vertical-axis clothes washers. 

Manufacturers also stated that efficiency level 5 (2.00 MEF/5.5 WF) would require the use of 

horizontal-axis clothes washers. Therefore, the data in Table 5.6.31 is subject to a platform 

change from agitator vertical-axis to horizontal-axis clothes washers between efficiency level 1 

and efficiency level 5. Given the persistent manufacturing cost difference between these 

platforms, an incremental cost “curve” with more intermediate data points would thus likely 

exhibit a steep step change wherever that platform change occurs. 

5.6.4.2 Manufacturer Interviews 

DOE conducted interviews with manufacturers of commercial clothes washers to develop 

a better understanding of the technologies used to improve the energy and water efficiency of 

these products. During the interviews, manufacturers were asked what design options or 

combination of design options would be required to increase the energy and water efficiency. 

The discussion helped DOE understand what design options manufacturers have already 

implemented and what additional design options DOE should consider. Additionally, the 

interviews provided a better understanding of the design strategies underlying the AHAM 

commercial clothes washer data submittal. The discussion below represents a consolidation of 

the manufacturers’ responses. 

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Background Information 

DOE learned that manufacturers may produce 3 distinct residential or commercial clothes 

washer platforms, each with inherent cost and efficiency attributes: 

 agitator vertical-axis clothes washers; 

 non-agitator vertical-axis clothes washers; and 

 horizontal-axis clothes washers. 

Agitator vertical-axis clothes washers immerse clothes in a vertically-oriented tub filled 

with a detergent and water solution. During the wash portion of the cycle, the agitator moves the 

suspended clothing through the solution. Agitator vertical-axis clothes washers fully immerse 

clothing during the rinse portion of the cycle as well. Since such designs immerse the clothing 

completely, their water consumption is inherently the highest among the 3 types of washer 

platforms. Additionally, since hot water heating represents the majority of the total energy used 

during the cycle, the total energy consumption of this washer type per cycle is usually also the 

highest among the 3 clothes washer platforms. 

Some residential vertical-axis clothes washer models combine the low cost of the vertical-axis 

platform with energy- and water-saving design options such as automatic fill control or spray 

rinse. However, the vertical-axis models with automatic fill control currently on the U.S. market 

utilize proprietary technology and are residential clothes washers. The spray-rinse option has 

seen limited implementation in the commercial clothes washer market due to perceived 

performance concerns and hence consumer resistance. 

Non-agitator vertical-axis clothes washers replace the agitator with an impeller, nutating 

plate, or other alternative manipulator. Non-agitator vertical-axis clothes washers do not need to 

suspend clothing completely in water to ensure adequate cleaning. This allows these washers to 

reduce tub fill levels, increasing water efficiency, and when hot water is used, energy efficiency. 

The design changes and additional components necessary to manufacture non-agitator verticalaxis clothes washers raise their price well above that for traditional agitator vertical-axis clothes 

washers. Non-agitator vertical-axis clothes washers have yet to be released as commercial 

models, and manufacturers expressed reservations about the viability of doing so due to the 

heavy-duty demands of commercial laundry applications. Two non-agitator vertical-axis 

residential clothes washers were introduced in the past at significant capital development 

expense by manufacturers, but were subsequently discontinued by those manufacturers. 

Horizontal-axis clothes washers use a horizontally-rotating wash tub with no agitator. As 

the tub rotates, the clothing is repeatedly lifted and dropped into a small pool of water and 

detergent solution at the bottom of the wash tub. Clothing is then rinsed in a similar manner. 

Since horizontal-axis washers do not need to suspend clothes in water to properly wash them, 

this technology platform can offer the highest water efficiencies on the market. When hot water 

wash cycles are used, the smaller amount of hot water required gives horizontal-axis clothes 

washers better energy efficiency than agitator vertical-axis clothes washers. However, a typical 

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EE-2006-STD-0127 COMMENT 39.2
horizontal-axis washer platform is significantly more expensive to manufacture than an agitator 

vertical-axis model. 

Design Options 

Manufacturers can use a variety of approaches to improve the energy and water 

efficiency of commercial clothes washers. Improvements to energy and water efficiency are not 

necessarily correlated, since some technologies may improve only energy efficiency or water 

efficiency, but not both. These technologies can be applied to different washer platforms with 

varying impact on MEF and WF. When manufacturers reach the efficiency limits of a particular 

platform, they must switch to an inherently more efficient platform to increase efficiency further. 

During the interviews, DOE requested input from manufacturers regarding the particular 

design options or strategies they are using to achieve improved energy and water efficiency. The 

following general approaches were discussed: 

• Reduced wash temperatures – manufacturers reduce water temperatures during the hot 

portions of the wash cycle. This increases the energy efficiency of the clothes washer since 

hot water consumption represents the majority of overall energy consumption. Reduced 

wash temperatures can be used on all washer platforms. Multiple manufacturers stated that 

reducing wash temperature negatively impacts wash performance. 

• Reduced fill levels – manufacturers can reduce the volume of water used in some washer 

designs for a given load size. This reduction increases the water efficiency of the washer 

and, when hot water is used, the energy efficiency of the washer. Multiple manufacturers 

stated that any further reduction in water fill level negatively impacts wash cleaning 

performance in agitator vertical-axis clothes washersf. 

• Additional temperature settings – by adding additional cooler wash temperature settings, 

manufacturers take advantage of the averaging function in the DOE clothes washer test 

procedure to achieve calculated energy consumption reductions. These design changes will 

only result in real-world energy savings if consumers choose the lower wash temperature 

cycles. Additional temperature settings can be implemented on all washer platforms. 

• Additional load-size settings – by incorporating additional user-selectable, lower washer 

load-size, and hence fill-level, settings, manufacturers use the averaging function in the DOE 

clothes washer test procedure to achieve calculated water consumption reduction and, when 

hot water is used, energy consumption reduction. These design changes will only result in 

real-world water and energy savings if consumers choose lower fill-level settings while 

operating the clothes washer. 

• Electronic controls – manufacturers stated that electronic controls would let them add more 

water temperatures, water fill levels, and other wash options to further utilize averaging 

f

 In vertical-axis agitator models, the clothes must “turn-over” in the tub by being pulled down into the tub by the 

oscillating agitator and then pushed back up along the outer wall of the tub. Turn-over is responsible for evenlydistributed cleaning of the garments. Reduced fill level in the tub reduces turn-over in agitator vertical-axis clothes 

washers, and subsequently reduces cleaning performance. 

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EE-2006-STD-0127 COMMENT 39.2
functions in the DOE test procedure, although this additional functionality comes at a 

significant cost premium over standard mechanical timers. Electronic controls can also be 

programmed to reset between users, preventing settings from “carrying over.” Electronic 

controls can be implemented on all washer platforms. 

• Water-temperature feedback – manufacturers can use temperature sensors and electronic 

controllers to increase energy efficiency by controlling water temperatures precisely. 

Currently, many washers use “open-loop” controls with no temperature feedback. 

Manufacturers add a safety margin in the form of extra hot water for warm-water fill cycles 

to ensure that minimum temperatures are met. Washers with open-loop controls operating 

under favorable conditions can thus create hotter wash water than desired or necessary when 

the temperature of the hot water supply is adequate or high. By adding a temperature sensor 

to provide water-temperature feedback, clothes washers with adaptive controllers can use less 

hot water in order to just reach the correct wash temperature, saving energy. As MEFs are 

pushed to higher levels, manufacturers may need to use more feedback as safety margins are 

decreased or eliminated. Water-temperature feedback can be used on all washer platforms 

equipped with electronic controls. 

• Spray rinsing – replacing immersion rinsing with a spray rinse reduces water consumption, 

along with energy consumption when hot rinse cycles are used. Spray rinsing has been 

previously used on all washer platforms but is currently not implemented by any 

manufacturer in commercial clothes washers due to performance concerns and the heavyduty demands of commercial laundry applications. A major route operator, WEB Service 

Company Inc. (WEB) of Redondo Beach, CA, testified during a California Energy Commission 

(CEC) hearing in 2001 that, in the late 1990s, it deployed a spray-rinse design option on a 

vertical-axis commercial clothes washer, but was forced to recall all of the washers19. At the 

same hearing, Whirlpool Corporation (Whirlpool) stated that it manufactured the spray rinse 

commercial clothes washers referred to by WEB and that “the spray rinse itself, was inadequate 

for the commercial application to get these clothes fully clean, get sand out of them and get the 

suds out of them.” 20 

• Partial-drain rinsing – which partially drains the wash tub prior to the rinse cycle and then 

reuses some of the wash water for the rinse cycle. This reduces water consumption and, 

when hot water is used for the rinse cycle, energy consumption. Partial-drain rinsing can be 

used on all washer platforms. While this design option is currently offered in a vertical-axis 

commercial clothes washer from a major commercial clothes washer manufacturer, it is not 

universally accepted by all equipment owners and users due to the user and owner perception of 

inadequate rinsing. 

• Higher spin-cycle speeds – washers with higher spin-cycle speeds can extract more water 

from clothing using mechanical energy, reducing the remaining moisture content (RMC). 

The DOE test procedure for commercial clothes washers credits a decrease in RMC as an 

increase in MEF. Higher spin-cycle speeds can be used on all washer platforms, but the 

mechanical suspension components of the clothes washer may need to be modified by the 

manufacturer at significant expense to accept the increased cyclical fatigue stress induced by 

the higher load forces. Additionally, one manufacturer expressed concern that the structure 

in which the washer is installed may need to be upgraded as well. 

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EE-2006-STD-0127 COMMENT 39.2
DOE requested that manufacturers comment on which platforms and design options they 

would use to produce washers capable of meeting the MEF and WF requirements of several 

standard levels: 

1.26 MEF/9.5 WF Baseline Efficiency Level 

Baseline commercial clothes washers must meet existing washer energy and water 

conservation standards. All manufacturers were able to meet this standard level by modifying 

their agitator vertical-axis clothes washer platforms. Modifications to meet MEF requirements 

included reducing water temperatures during wash and rinse cycles or incorporating additional 

user-selectable cooler wash temperature settings to the clothes washer’s control panel. 

In order to meet this WF requirement, manufacturers reduced water usage during the 

rinse cycle by redesigning their wash baskets, implementing lower rinse-water fill levels, or 

using partial-drain rinse technology. The incremental cost of allowing multiple fill levels is 

relatively minor, since additional pressure switches (beyond the one already found in each 

washer) are inexpensive to implement. Based on these statements, DOE estimates that the 

incremental cost of upgrading agitator vertical-axis clothes washers to meet the 1.26 MEF/9.5 

WF was less than 10 percent of the baseline washer cost. A physical teardown of units 

compliant with current standards and older 11.0 WF units would give DOE further insight into 

the details of the conversion costs. 

Currently, most consumers in commercial laundry settings receive no monetary benefit 

from selecting colder wash cycles or lower water levels. Only newer, electronic control systems 

using card readers can offer this functionality, and then only if the route operator enables it. 

Thus, manufacturers are not sure if consumers using commercial clothes washers will select 

lower wash temperatures or lower water settings, since most consumers pay the same amount of 

money per load and are unlikely to select wash options that they believe could result in decreased 

washer performance. Additionally, commercial clothes washers are frequently overloaded or 

loaded with heavily-soiled clothing, which implies that consumers are even less likely to select 

reduced wash temperatures and fill levels. 

1.42 MEF/9.5 WF Efficiency Level 

DOE learned that this standard level represented an incremental improvement for 

manufacturers. Since this standard level only requires an increase in MEF, with no increase in 

WF over the baseline, manufacturers stated that they were familiar with the design changes 

necessary to produce washers at this standard level. It is believed that this level could be met 

with additional modifications to agitator vertical-axis clothes washer designs, even with the 

continued use of electromechanical controls. 

All manufacturers planned on using further reductions in water temperature to meet the 

MEF requirements of this standard level. This may include incorporating additional userselectable wash temperature settings. However, manufacturers cautioned that further reductions 

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EE-2006-STD-0127 COMMENT 39.2
in wash water temperatures would lead to decreases in wash performance. The magnitude of 

these concerns varied by manufacturer. 

Manufacturers did express some additional concerns about the steps necessary to meet 

this standard level. One concern is that electromechanical controls do not reset between washes. 

While this may not represent a problem for a residential clothes washer with a single user, usercontrollable settings could “carry over” between users of commercial clothes washers, causing 

confusion and decreased wash performance. One manufacturer also expressed concern that 

water temperature reductions necessary to meet this standard level would encourage biofilm 

growth inside the washer. 

1.60 MEF/8.5 WF Efficiency Level 

DOE learned that this standard level would likely represent a significant change in 

commercial clothes washer design. Since this standard level incorporates an increase in both 

MEF and WF, not all manufacturers are familiar with the design changes necessary to produce 

washers that meet this standard level, and how these design changes will affect washer 

performance and reliability. 

DOE also learned that the washing practices of commercial clothes washer users render 

some energy and water efficiency-enhancing design options impractical. Customers frequently 

overload washers at laundromats and multifamily housing laundry facilities in order to minimize 

their washing costs. These customers are more concerned with lowering their overall washing 

cost than with cleaning performance. Washer overloading significantly decreases the 

performance of efficiency-enhancing design options like spray rinsing and partial-drain rinsing. 

Additionally, some customers go to laundromats to avoid washing heavily-soiled loads in their 

own residential clothes washers. These customers would be significantly affected by design 

options that cause performance decreases. Customers have already complained that spray 

rinsing cannot adequately remove sand from heavily-soiled clothing loads, for example. 

As wash water temperatures drop to meet the 1.60 MEF requirements, manufacturers 

have the option of lengthening the wash cycle to improve wash performance. However, any 

increase in cycle length is not in the economic interest of route operators, as longer cycle lengths 

can result in fewer washer cycles per day from a given clothes washer. Manufacturers could also 

offer user-selectable water fill levels at this efficiency level in order to take advantage of the WF 

credit that such a switch entails. According to manufacturers, the savings from giving 

commercial clothes washer end-users such a choice would be illusory since users have no 

economic incentive to lower the water level, since they typically pay the same amount per wash, 

regardless of fill level. 

Some manufacturers have made agitator vertical-axis clothes washers with spray rinse for 

the commercial market in the past. However, as discussed above, manufacturers have noted 

consumer resistance to commercial clothes washers with a spray rinse, as such systems may not 

result in adequate rinse performance, particularly for heavily soiled items. 

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Multiple commercial clothes washer manufacturers stated that this efficiency level was 

beyond the realistic reach of agitator vertical-axis clothes washers for use in the commercial 

laundry market. According to these manufacturers, such washer platforms would not yield 

adequate wash and rinse performance in commercial settings. 

As a result, most manufacturers of commercial clothes washers stated that this efficiency 

level could only be met with non-agitator vertical-axis washers or horizontal-axis washers. Such 

a platform transition would let manufacturers reduce washer fill levels, since neither of these 

platforms require clothing to be completely immersed and suspended in water. Electronic 

controls would let manufacturers improve washer performance, as well as add additional water 

fill options, water temperature options, and wash cycle options. Based upon the DOE test 

procedure, additional lower water fill-level options increase WF, and additional lower water 

temperature options increase MEF. Manufacturers also stated that higher spin-cycle speeds 

could increase MEF by reducing the RMC. 

This standard level thus presents problems for the laundromats and route operators who 

own and operate commercial clothes washers. Existing inventories of replacement parts for 

vertical-axis washers would start becoming obsolete as manufacturers transition to incompatible 

platforms, potentially representing significant stranded capital. Furthermore, replacement parts 

for high-efficiency washers can be more expensive than replacement parts for agitator verticalaxis clothes washers. For example, replacing a failed control circuit board costs significantly 

more than replacing a failed electromechanical controller. 

One manufacturer noted that multiple non-agitator vertical-axis clothes washer platforms 

have been withdrawn from the residential market. Since none of the remaining non-agitator 

vertical-axis residential clothes washer manufacturers expressed an interest in converting these 

washer platforms for use in the commercial laundry business, the most likely result of a 1.60 

MEF/8.5 WF efficiency level is a complete transition to horizontal-axis clothes washers. 

1.72 MEF/8.0 WF Efficiency Level 

All manufacturers stated that this efficiency level was beyond the reach of agitator 

vertical-axis clothes washers in a commercial laundry setting. Thus, a switch would be required 

to either non-agitator vertical-axis or to horizontal-axis washer platforms with the same issues as 

noted for the 1.60 MEF/8.5 WF efficiency level. Since none of the manufacturers expects to 

manufacture non-agitator vertical-axis clothes washers for the commercial laundry market, the 

most likely outcome would be the adoption of horizontal-axis clothes washers. 

1.80 MEF/7.5 WF Efficiency Level 

According to manufacturers, neither vertical-axis clothes washer platform can reach this 

efficiency level in a commercial laundry setting and provide satisfactory wash and rinse 

performance. Thus, this efficiency level is a de-facto horizontal-axis standard. According to all 

manufacturers, the cost of manufacturing a 1.80 MEF/7.5 WF horizontal-axis commercial 

clothes washer is the same as manufacturing a 2.00 MEF/5.5 WF model. Thus, they saw no 

reason to consider this efficiency level. 

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2.00 MEF/5.5 WF Efficiency Level 

All manufacturers of commercial clothes washers currently manufacture a horizontalaxis, commercial clothes washer in this MEF/WF range. As a result, AHAM was able to submit 

a shipment-weighted incremental cost for this efficiency level, for which all manufacturers 

assumed the use of a horizontal-axis clothes washer platform. 

2.20 MEF/5.1 WF Efficiency Level 

Manufacturers stated that this standard level would require additional modifications to 

their horizontal-axis commercial clothes washer platforms. All manufacturers would need to 

replace any electronic motor-driven transmissions with electronically-controlled direct-drive 

motors. Further reductions in water temperatures and water fill levels would also be necessary. 

As part of interviews with DOE, manufacturers estimated that the incremental manufacturing 

cost increase to meet this standard level would range from $316 to $450 per clothes washer. 

5.6.4.3 Review of the Most Recent TSD for Residential Clothes Washers 

In 2001, DOE concluded a rulemaking for residential clothes washers. The intent of this 

section is to review some of the conclusions drawn in the 2000 TSD which supported that 

rulemaking, to update the data presented in it, and to assess in which ways the residential clothes 

washer TSD can be used in the context of this commercial clothes washer rulemaking. In 

particular, this review will focus on the manufacturing costs published in the 2000 TSD. First, 

the 1996 AHAM residential clothes washer cost data submittal provided for the 2000 TSD will 

be examined, followed by the 2000 reverse-engineering analysis and an update on the lowvolume manufacturer case. 

1996 AHAM Cost and Energy Use Data Submittal Review 

In 1996, manufacturers submitted manufacturing cost and energy use estimates by 

efficiency level for residential clothes washers to AHAM. This data was then aggregated by 

market share and efficiency level to prevent the disclosure of confidential information, and the 

results were used in the analysis reported in the 2000 TSD. While this process yielded viable 

results in the residential clothes washer rulemaking, the results are not directly applicable to the 

current commercial clothes washer rulemaking due to differences in the following key 

parameters: (1) intended use and cycle life, (2) production scale, (3) technical advancements, (4) 

market share, (5) platform mixing, and (6) incompatibility of the MEF and WF pairings in the 

data submittal. 

Intended Use and Cycle Life 

Clothes washer manufacturers have traditionally designed their commercial units to share 

many parts with their residential platforms. Shared components typically consist of parts that do 

not affect unit life, such as cabinet stampings, that may or may not be selectively upgraded. For 

example, entry-level residential clothes washer cabinets typically feature a powder-coated plastic 

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finish whereas commercial models may feature a more durable enameled finish. Purchased 

components such as motors, timers, and switches may also be customized to reflect the different 

and more rigorous usage patterns expected in commercial applications. For example, one 

manufacturer stated that their commercial clothes washers are expected to last 12,000 wash 

cycles whereas residential models are expected to last 6,000 or fewer wash cycles. 

Production Scale 

In 1996, a twenty-fold scale difference existed between residential and commercial 

clothes washer market unit shipments. Since then, residential clothes washer shipments have 

grown while commercial clothes washer sales have stagnated or declined. As a result, the 

current scale difference is more than forty-fold. 

The scale difference helps explain why commercial clothes washers have traditionally 

been a product extension of existing residential clothes washer platforms for most manufacturers. 

By sharing many components with residential models, research and development, tooling and 

equipment, and other costs can be spread over the largest number of clothes washers. 

Consequently, any additional investment required for commercial clothes washers alone is 

depreciated over a much smaller production volume. 

As efficiency standards are raised, manufacturers may be required to make investments in 

the form of capital expenditures, research and development, and implementation to meet such 

standards. Investments such as new tooling and research, in particular, are “step” functions, 

requiring a minimum investment regardless of production volume. A standard that affects 

commercial clothes washers first may thus require a substantial investment that can only be 

depreciated over a much smaller production volume. 

As a result of the much lower production volumes, the per-unit conversion costs to 

accommodate higher efficiencies are greater per efficiency increment for commercial clothes 

washers than they are for residential models. Therefore, Table 4.2 published in the 2000 TSD 

(duplicated below as Table 5.6.32) is not valid for commercial clothes washers because the fixed 

costs are assumed to be depreciated over a much larger product volume and because the highervolume production processes manufacturers envisioned minimize variable cost increases. Most 

manufacturers of residential clothes washers in 1996 had production levels in excess of 300,000 

units per year, with the leading manufacturer producing about 3.5 million vertical-axis washers 

per year. In contrast, the 2 leading commercial clothes washer manufacturers in 2007 have 

commercial clothes washer production levels of about 100,000 units per year. 

Currently, as in 1996, there is a low-volume manufacturer that operates in both the 

residential and commercial clothes washer markets. While its volumes in the residential market 

are very small on a percentage basis, this manufacturer is very prominent in the commercial 

clothes washer market. Unlike its diversified competitors, this company exclusively 

manufactures laundry equipment. A review of the Securities and Exchange Commission (SEC) 

10-K documents revealed that, as of 2005, this company derived 22 percent of its total revenue 

from the sale of front- and top-loading clothes washers and 87 percent of that income was from 

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the commercial market. As a result, this company will be affected disproportionately by the 

commercial clothes washer rulemaking compared to its competitors, for whom commercial 

clothes washers represent about 2 percent of total clothes washer sales. 

Table 5.6.32 1996 AHAM Residential Clothes Washer Cost Data Submittal 

Product Characteristics Incremental Variable Costs Total Incre- No. 

($ per Unit) Fixed mental of 

Costs 

($ per 

Mfg. 

Cost 

ResPercent MEF WF Ma- Labor Over- Total ponImprove- terials head unit) ($ per dents 

ment unit) 

Baseline 0.817 13.779 

5 0.860 13.732 $0.01 $0.01 $0.00 $0.02 $0.07 $0.09 5 

10 0.908 13.710 $0.25 $0.04 $0.01 $0.30 $0.61 $0.91 5 

15 0.961 13.670 $3.18 $0.10 $0.04 $3.32 $1.01 $4.33 5 

20 1.021 13.342 $10.71 -$0.02 $1.80 $8.89 $6.21 $15.10 5 

25 1.089 9.220 $36.14 $8.61 $0.09 $44.84 $19.29 $64.13 5 

30* 

35 1.257 7.601 $86.73 $10.94 $7.78 $105.45 $22.72 $128.17 5 

40 1.362 7.610 $87.15 $10.94 $7.78 $105.87 $22.72 $128.59 5 

45 1.485 8.570 $125.58 $15.52 $14.51 $155.61 $24.67 $180.28 4 

50 1.634 8.570 $132.40 $15.68 $14.51 $162.59 $24.67 $187.26 4 

* No data were submitted at this efficiency level 

Technical Advancements 

While the general function of clothes washers has not changed since the 2000 TSD, many 

different technologies have been implemented. As with dishwashers, dehumidifiers, and other 

residential appliances, clothes washers are built on platforms whose baseline performance can be 

improved with design options. Some platforms are inherently more energy and water efficient 

than others, allowing a manufacturer to use fewer design options to reach a particular efficiency 

level, but there are efficiency limits inherent to every platform regardless of how many design 

options are employed. These limits affect the MEF as well as the WF. 

Clothes washers currently often use electronic controllers instead of electromechanical 

controllers, which were more prevalent at the time of the 2000 TSD. Electronic controllers 

usually carry a cost premium over electromechanical timers, driving up manufacturing cost. 

However, such controllers are appealing to customers and are required for some design options. 

Besides enabling certain design options, electronic controllers allow owners to more easily 

monitor washer utilization, functional status, and other parameters. There are potential reliability 

benefits as well. For example, one reason that variable-water-height selectors are atypical in 

commercial vertical-axis clothes washers is that owners prefer not to give users the ability to 

select water levels. If they did, users could attempt to wash a full load on a “low water” setting, 

potentially damaging the washer and/or the clothes being washed. Electronic controllers may be 

able to detect such overload conditions and stop the wash cycle before the clothes washer is 

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harmed. Alternatively, controllers can be programmed to “reset” to default settings after each 

wash cycle. This forces the end-user select the appropriate cycle for each use, potentially 

reducing the incidence of accidental overloads. 

Some manufacturers have also phased out mechanical transmission and clutch systems, 

replacing them with variable-speed electronic drive systems. Benefits include a reduction in 

mechanical complexity, increased cabinet space to accommodate potential expansion of the 

basket/tub, and greater wash program flexibility. The substitution of electronics for mechanical 

systems can increase overall unit cost, particularly if fixed in-house assets that had been used to 

manufacture mechanical transmission and clutch systems become stranded assets. 

Many design options available in residential clothes washer have yet to find application 

in commercial clothes washers. The reliability and longevity requirements of commercial 

clothes washers combined with the production scale issues are such that manufacturers avoid 

adding design options unless necessary. As the part count increases, so does the probability that 

the clothes washer will break down, and purchased parts sourced just for commercial clothes 

washers are likely to carry a cost premium. Thus, DOE expects manufacturers will continue to 

introduce new features first in the residential markets before transitioning them to the 

commercial field. 

Since the 2000 residential clothes washer TSD was written, there have been numerous 

technological advances incorporated into clothes washers, and the manufacturing costs submitted 

to AHAM were based on residential clothes washer models which are no longer in production. 

Thus, even if DOE could ascertain the manufacturing cost differential between commercial and 

residential clothes washers in 1996, that differential would no longer be valid for current models. 

Most importantly, manufacturers have been able to improve the MEF and WF of agitator 

clothes washers at a much lower cost than they projected in 1996. Instead of using horizontalaxis or non-agitator vertical-axis clothes washers as projected to meet a 1.26 MEF, current 

baseline 1.26 MEF commercial clothes washers consist of agitator models with reduced water 

consumption, lower wash temperatures, and improved control systems. Thus, manufacturers 

were able to reach the current efficiency requirements at much lower cost than projected in 1996. 

One manufacturer noted that the costs of improved control systems are substantially higher than 

those of the electromechanical controls they replaced and that the wash performance and hence 

end-user utility of vertical-axis clothes washers are affected by lower WF and higher MEF 

requirements. 

Market Share 

The market shares that AHAM used to aggregate manufacturer-submitted data were valid 

for the residential clothes washer market in 1996. However, since then there has been significant 

consolidation by domestic producers, and multiple foreign brands have started selling their 

clothes washers in the U.S. More importantly, the market shares of producers in the residential 

clothes washer market are not equivalent to the market shares of manufacturers in the 

commercial clothes washer industry. 

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Four to 5 residential clothes washer manufacturers submitted manufacturing cost data 

estimates for each efficiency level for the 1996 AHAM data request. However, there are 

currently essentially only 3 U.S. commercial clothes washer manufacturers: Alliance Laundry 

Systems LLC (Alliance), General Electric GE Consumer & Industrial (GE), and Whirlpool (via 

its acquisition of Maytag Corporation (Maytag)). The low number of manufacturers limits 

current AHAM data submittals to DOE since AHAM requires a minimum of 3 data points per 

efficiency level before it publishes any results. 

Since AHAM adjusts incremental manufacturing cost data submittals by efficiency level 

on a market-share basis, the manufacturing costs submitted by the largest manufacturers have the 

greatest weight. As noted above, the distributions of market share by manufacturer for 

commercial and residential clothes washers are quite different. Since DOE does not have access 

to the disaggregated data, there is no opportunity to compensate for market share differences 

between markets, even if the costs of manufacturing residential and commercial clothes washers 

were the same. 

Platform Mixing 

Attempting to update the 1996 AHAM data submittal is hindered by its aggregation of 

vertical- and horizontal-axis clothes washers. Based on the AHAM-supplied energy and water 

use data, reproduced in Table 5.6.33, DOE assumes that the cost and energy use tables contained 

only agitator vertical-axis data for efficiency improvement levels of up to, and including, 20 

percent. This assumption is driven by the consistent water usage up to that point and the low 

incremental costs to reach that efficiency level. Similarly, DOE assumes that the 2 highest 

efficiency levels, 45 and 50 percent improvement, exclusively incorporated horizontal-axis 

clothes washers. The 25 to 40 percent improvement categories appear to have aggregated highefficiency vertical- as well as horizontal-axis clothes washers. 

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Table 5.6.33 1996 AHAM Residential Clothes Washer Energy and Water Use Data 

Submittal 

Product Characteristics Energy Use Water Use 

(kWh/cycle) 

Percent 

Improve 

-ment 

MEF Total 

Energy 

w/Dryer 

(kWh 

/cycle) 

Clothes 

Containe 

r (ft3

) 

Hot 

Water 

Machin 

e 

Energy 

Dryer 

Energy 

(gal/ 

cycle) 

(gal/ 

ft3) 

Baseline 0.817 3.227 2.847 1.587 0.209 1.430 39.181 13.779 

5 0.860 3.165 2.817 1.543 0.209 1.413 38.613 13.732 

10 0.908 3.017 2.822 1.408 0.209 1.400 38.613 13.710 

15 0.961 2.833 2.832 1.216 0.209 1.407 38.621 13.670 

20 1.021 2.739 2.893 1.113 0.218 1.408 38.446 13.342 

25 1.089 2.292 2.866 0.715 0.304 1.273 26.600 9.220 

30* 

35 1.257 1.866 2.749 0.462 0.133 1.270 21.030 7.601 

40 1.362 1.859 2.749 0.462 0.133 1.263 21.030 7.610 

45 1.485 1.651 2.736 0.429 0.114 1.107 23.405 8.570 

50 1.634 1.574 2.736 0.413 0.114 1.047 23.405 8.570 

* No data were submitted at this efficiency level. 

Since DOE does not have access to the disaggregated data and the clothes washer 

platforms that underlie the AHAM data submittals, there is no method by which DOE can assess 

how relevant the data submittal is to the current rulemaking. It is not clear to DOE which 

models were submitted at each efficiency level, whether these models use the same platforms as 

current commercial clothes washers, nor what efficiency improvements manufacturers have been 

able to achieve with these models since 1996. 

Incompatibility of the MEF and WF Pairings 

Table 5.6.33 shows the lowest shipment-weighted WF at 1.26 MEF. No vertical-axis 

clothes washers could reach 1.634 MEF in 1996, suggesting that the clothes washers at the 2 

highest efficiency levels consisted of horizontal-axis clothes washers whereas baseline units 

consisted of agitator vertical-axis clothes washers. The WF is lowest at 1.26 MEF, indicating 

that the shipment-weighted WF for that efficiency level included clothes washers that had a 

lower WF than residential horizontal-axis clothes washers did at that time. 

DOE is aware of an agitator vertical-axis commercial clothes washer platform from a 

major manufacturer that had achieved a 7.3 WF via spray rinse. However, this unit was 

withdrawn from the market a number of years ago due to end-user complaints regarding rinse 

performance. The CEC database of current commercial clothes washers lists no vertical-axis 

clothes washers with a similar water factor. The closest model is an agitator vertical-axis washer 

platform with an 8.8 WF. The single vertical-axis clothes washer platform currently listed in the 

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CEC residential clothes washer database that meets the 7.6 WF does not exist in a commercial 

version and consists of a non-agitator design. 

Thus, the results at 1.26 MEF in Table 5.6.33 suggest multiple platforms, likely 

consisting of agitator vertical-axis with spray rinse, non-agitator vertical-axis, and horizontalaxis residential clothes washers. Neither spray-rinse agitator nor non-agitator clothes washers 

are currently in production for commercial purposes. The incompatibility between the WF of 

machine properties submitted to AHAM for the 1996 data submittal and machines currently on 

the market is yet another indication of how the projections of manufacturers diverged from the 

agitator vertical-axis clothes washers they developed to meet the 1.26 MEF/9.5 WF 

requirements. 

Conclusion 

There are sufficient changes in market conditions due to intended use and cycle life, 

production scale, technical advancements, and market share to preclude the use of the 1996 

AHAM data submittal as a basis for the current commercial clothes washer analysis. 

Furthermore, the 1996 AHAM data submittal cannot be factored into the analysis due to platform 

mixing and the resulting inability to disaggregate the data into vertical- and horizontal-axis 

machines. 

2000 TSD Reverse-Engineering Review 

Further manufacturing cost data by efficiency level was developed for the 2000 

residential clothes washer rulemaking by DOE. Since DOE has access to this data, DOE has 

decided to review and publish data that remains relevant to the current commercial clothes 

washer rulemaking. 

Reviewed Models 

For the 2000 residential clothes washer TSD, DOE reverse-engineered 8 residential 

clothes washers in 1999 from manufacturers with substantial market shares. DOE subsequently 

developed cost models to estimate the manufacturing costs of these washers at varying 

production levels. 

The market share covered by the residential clothes washer platforms reverse-engineered 

in 1999 was about 80 percent. Three of the washers shared a chassis with commercial clothes 

washers in 1999. DOE could make estimates regarding the costs to update these platforms for 

commercial use, but the market share covered by these platforms is currently less than 20 percent 

of the commercial market, limiting the usefulness of the results. 

All 3 of the major manufacturers currently serving the commercial clothes washer 

industry have introduced new models or significantly revised existing models since the 2000 

residential clothes washer TSD. Some manufacturers have updated the drive systems and other 

major system components to differentiate their products or improve energy efficiency. As a 

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result, there have been significant changes in the baseline cost of clothes washers that the 2000 

TSD could not have analyzed, even if it had reviewed commercial clothes washer models. 

Market Share and Scale 

The U.S. commercial clothes washer market is very small compared to the residential 

clothes washer market. Whereas shipments of residential clothes washers have been increasing, 

with more than 9.2 million units in 2005, commercial clothes washer sales have stagnated or 

declined to about 200,000 units per year. The residential clothes washer market is dominated by 

the merged Whirlpool-Maytag entity, which has an approximate combined market share of 70 

percent. The residential clothes washer sales of this entity exceed 6.5 million units per year, 

more than thirty times the entire commercial clothes washer market. 

This scale difference is important in this analysis because agitator vertical-axis residential 

and commercial clothes washers typically share many parts to minimize tooling and equipment 

investments. Thus, a manufacturer that benefits from high manufacturing volumes on the 

residential side has a much larger potential base of units over which to depreciate investments. 

Commercial assembly lines can be repurposed towards residential clothes washer production if 

the commercial vertical-axis washer platform is no longer cost effective to produce. 

While the largest competitor in the U.S. clothes washer manufacturing business may not 

realize much cost benefit due to manufacturing scale in moving to 6.5 million units per year 

versus the 1.5 million units per year modeled during the 2001 residential clothes washer 

rulemaking, there are other advantages to scale. For example, research and development and 

other overhead functions can be leaner as a percentage of sales revenue, yet still have far more 

available resources than comparable departments at lower-volume competitors. 

High-volume competitors have a long history of improving the performance of agitator 

vertical-axis clothes washers via add-on design options such as spray rinse, nutating plates, and 

other means. For a lower-volume manufacturer, it is inherently more difficult to assemble and 

defend an intellectual-property portfolio. Similarly, a low-volume manufacturer may have to 

wait for innovations to trickle down from common suppliers since high-volume manufacturers 

typically get first (and sometimes exclusive) access to new technologies. 

Manufacturers whose production comprises a high percentage of commercial clothes 

washers are thus impacted disproportionately by any regulatory burden regarding commercial 

clothes washers. One low-volume U.S. clothes washer manufacturer was contractually barred 

from manufacturing residential clothes washers from 1999 until 2004. While its subsequent SEC 

10-K reports show significant growth in the residential market segment, commercial sales are 

still substantially higher. As a result, this low-volume manufacturer is not only concentrated in 

the commercial clothes washer market, but its lack of diversification makes it particularly 

sensitive to any impacts on its commercial clothes washer business as well. 

The Low-Volume Manufacturer Case 

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The Low-Volume Manufacturer (LVM) has been successfully competing with much 

larger competitors in the commercial laundry market for several years. Based on the LVM's 

public SEC 10-K filings, DOE has estimated that the LVM derives about a third of its total 

revenues from the sales of clothes washers and dryers, which are usually bundled. Clothes 

washer sales by themselves account for more than 20 percent of total revenue. Laundry 

equipment for institutional use largely makes up the balance. For a detailed breakdown of LVM 

revenues by product line and market segment, see Appendix 5C of the TSD, which details DOE's 

methodology and results for the LVM analysis. 

As of 2005, agitator vertical-axis clothes washers sold by the LVM into the commercial 

market segment represented about 70 percent of unit shipments and about 60 percent of total 

commercial clothes washer revenues. Thus, any legislation that eliminates the use of such 

clothes washers from the commercial market would affect the LVM disproportionably due to the 

relative importance of the business and its effect on manufacturing scale. Such a transition also 

poses a business risk since a platform change will reduce the value of accumulated spare-parts 

inventories, technician training, etc. to route operators. Thus, any switching cost to other brands 

could be substantially reduced. 

The LVM released a horizontal-axis clothes washer for sale in 1999 and does not 

presently manufacture any non-agitator vertical-axis clothes washers. As of 2005, its sales of 

horizontal-axis clothes washers represent approximately 20 percent of total washer unit 

shipments and approximately 35 percent of total washer revenues. Given the scale of the 

manufacturer at the time, the design was likely optimized for very low production volume. 

Should the entire commercial clothes washer industry be forced to migrate to horizontal-axis 

clothes washers, the LVM would thus have to make substantial investments to make its design 

more cost competitive. While the LVM is already at work to reduce horizontal-axis unit costs, a 

market transition to horizontal-axis washers accelerated by federal standards would most likely 

result in the LVM moving its horizontal-axis manufacturing offshore. 

However, unlike its larger rivals, the LVM does not benefit from very large scale in its 

residential operations to help amortize the investments in research, development, plant 

expenditures, and implementation expenses. The size of the commercial clothes washer market 

by itself is simply too small to justify large lump-sum investments. The agitator vertical-axis 

units that the LVM manufactures have benefited from years of investments and refinements, 

whereas the horizontal-axis model received its first update in 2003. 

Besides benefiting from ongoing development and investments, agitator vertical-axis 

clothes washers at the LVM also benefit from well-depreciated equipment and tooling and a 

long-term knowledge base. In the past, the LVM had residential sales well in excess of its 

commercial clothes washer sales before a non-compete contract cut off the LVM from the 

residential market from 1999 until 2004. Thus, while the LVM has gained the experience of 

producing hundreds of thousands of vertical-axis clothes washers per year, it has yet to gain the 

same experience with its horizontal-axis clothes washer line. 

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The loss of the commercial market for agitator vertical-axis clothes washers is likely to 

make residential models of those clothes washers too expensive to manufacture due to the much 

smaller scale. Whether the LVM could remain in the horizontal-axis clothes washer business 

despite the loss of the agitator vertical-axis clothes washer business is also uncertain. To date, 

the LVM has been able to grow its business despite adverse market conditions and much larger 

competitors. 

Implications of Scale for the Low-Volume Manufacturer 

As discussed previously, most of the clothes washers under review in the 2001 residential 

clothes washer rulemaking did not share a chassis with a commercial model. Thus, the results of 

the engineering analysis in the 2000 TSD do not apply to present day commercial clothes 

washers except for a very narrow set of observations. 

A universal factor in manufacturing is scale, which describes how many units over which 

a fixed investment can be amortized. As part of the 2000 reverse-engineering analysis for 

residential clothes washers, DOE tried to understand the implications of low-volume 

manufacturing. Figure 5.6.24, originally published as Figure 5.10 in the 2000 residential clothes 

washer TSD, averages the cost differences among multiple baseline vertical-axis residential 

clothes washers at production levels of 1.5 million and 0.3 million units per year. It also 

averages horizontal-axis results for the residential horizontal-axis clothes washers that DOE 

reverse-engineered. 

Figure 5.6.24 2000 Low-Volume versus High-Volume Clothes Washer Cost Disadvantage 

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EE-2006-STD-0127 COMMENT 39.2
While the units under review in the 2000 residential clothes washer TSD are not 

applicable to the current commercial clothes washer analysis, the impact of manufacturing scale USD 

is still relevant to the commercial clothes washer market. As manufacturing volumes shrink, 

labor costs rise due to growing inefficiencies within the fabrication and assembly lines. The 

effect of manufacturing scale on depreciation is even more pronounced, as there are minimum 

tooling and equipment investments required to start operations, regardless of what the actual 

manufacturing volume turns out to be. Careful design will minimize the amount of additional 

tooling required to bring a new product to market. 

Results from the 2000 TSD analysis for the effects of manufacturing scale are presented 

as follows, recognizing that similar results will likely apply to commercial clothes washers. 

Figure 5.6.25 examines the case of very low-production volumes (100,000 units per year) versus 

producing at high volumes (1,500,000 units per year). Driven mainly by increases in 

depreciation costs, the very low-volume manufacturing cost increment over high-volume 

manufacturing increases to about $80 for both vertical- and horizontal-axis clothes washers. 

$90.00 

$80.00 

$70.00 

$60.00 

$50.00 

$40.00 

$30.00 

$20.00 

$10.00 

$0.00

V-Axis H-Axis

Other 

i

Depreciation 

Labor 

Mater als 

Figure 5.6.25 2000 Cost Disadvantage of Producing 100,000 versus 1.5MM Clothes 

Washers per Year with Green Field Facility 

The agitator vertical-axis clothes washer market is largely commoditized, resulting in 

fierce price competition. A $156 price difference for the end user ($80 manufacturing cost 

multiplied by a 1.93 total markup (see Chapter 7 of this TSD)) is not likely to be sustainable. 

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However, the LVM is aided in this product segment by the extant tooling and equipment, years 

of research and development, etc. which represent a sunk cost. 

In contrast, the horizontal-axis clothes washer manufacturing line would have to increase 

its output by multiples to meet the unit demand that the vertical-axis line currently sustains. 

Since the 2 platforms do not share many components, the vertical-axis line would be likely to be 

written off, while substantial investments would be required to expand the output of the 

horizontal-axis line. Such investments may not be justified by the potential market for them, and 

the larger rivals have a great advantage in terms of leveraging their residential clothes washer 

shipments to minimize depreciation on a per-unit basis. 

Thus, while the LVM may be able to compete with its bigger rivals on the agitator 

vertical-axis platform due to depreciated plant and equipment, prior high-volume experience, and 

a long learning curve, it would be competing at a great disadvantage with its larger rivals should 

horizontal-axis commercial clothes washers become the only platform that can meet future 

energy efficiency standards. 

Manufacturers operating at very low volumes are likely to face margin pressure for both 

vertical- and horizontal-axis clothes washers. To counter pressure from high-volume 

manufacturers, low-volume producers have to compete on the basis of service, reliability, 

bundling, and product differentiation. Its long legacy in the agitator vertical-axis market also 

aids the LVM in competing successfully with larger rivals. 

Conclusion 

In conclusion, the LVM faces larger rivals in all of the clothes washer markets it 

competes in, yet the LVM has been able to grow its revenue despite being heavily concentrated 

in the stagnant commercial clothes washer market. As a result, the elimination of the agitator 

vertical-axis clothes washer platform from the commercial clothes washer market would impact 

this manufacturer disproportionately and could therefore represent a material risk to the 

company. 

Other Observations Regarding the 2000 Residential Clothes Washer TSD 

Historic Background 

When DOE began the 2001 residential clothes washer rulemaking, the U.S. residential 

clothes washer market consisted almost exclusively of vertical-axis platforms. Table 3.9 in the 

2000 TSD noted that vertical-axis clothes washers comprised a 99.9 percent market share as of 

1995. Available horizontal-axis clothes washers were limited to imported goods and 2 domestic 

platforms. While the majority of overall clothes washer shipments in the U.S. still consist of 

vertical-axis clothes washers, the shipment levels and market share of horizontal-axis clothes 

washers have grown significantly. 

Unlike in 1995, all remaining U.S. manufacturers now sell horizontal-axis clothes 

washers that are either produced in their own factories or outsourced. The majority of residential 

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horizontal-axis clothes washers sold in the U.S. today are manufactured abroad. While a greater 

proportion of commercial clothes washers are made domestically, significant market scale 

differences remain. Thus, as markets for vertical-axis clothes washers decline, domestic clothes 

washer production will likely decline also. 

In the 1996 AHAM data submittal, the maximum potential improvement was capped at 

an MEF of 1.634, whereas horizontal-axis clothes washers from multiple vendors currently reach 

MEFs in excess of 2.00. Manufacturers have also increased the basket capacity of vertical- and 

horizontal-axis clothes washers, reaching up to 4 cubic feet in some residential models. The 

WFs are also significantly lower on several current horizontal-axis clothes washers found in 

either residential or commercial clothes washer markets than they were for models in the 2000 

TSD. 

As a result of the residential clothes washer rulemaking, the standards for residential 

clothes washers were increased in 2 steps, reaching an MEF of 1.26 as of January 1, 2007. When 

the standard was signed into law, no horizontal-axis clothes washer MEFs were below 1.26. 

Thus, only vertical-axis clothes washers were affected by the rulemaking. In the interim, 

manufacturers worked to find the most cost-effective way to modify their vertical-axis platforms 

to meet the current minimum MEF. 

At the time of the 2000 TSD, a correlation was noted and assumed between MEF and WF 

(see Table 5.6.33). However, no WF was imposed in the final rulemaking. As a result, 

manufacturers could largely focus on reducing the energy content of the wash and rinse water 

rather than having to jointly focus on the MEF and the WF. None of the agitator vertical-axis 

clothes washers that currently meet the 1.26 MEF minimum efficiency standard also reach the 

WF predicted for that efficiency level by the 2000 TSD. Typically, such current vertical-axis 

clothes washers use 2 more gallons of water per cubic foot of capacity than the WF associated 

with the 1.26 MEF standard in the 2000 TSD. 

Impact of Product Test Procedures 

Based on language in EPACT 2005, DOE is required to rate commercial clothes washers 

with the same test procedure established for residential clothes washers. (EPACT 2005, section 

136(f)) DOE adopted test procedures for commercial clothes washers in a final rule published 

on October 18, 2005. (70 FR 60407, 60416) The testing procedure for residential clothes 

washers is published in Appendix J1 to 10 CFR Part 430, Subpart B. 

When calculating MEF, the DOE test procedure factors in end-user-selectable variables 

including the wash and rinse water temperatures, and fill level. Thus, adaptive water levels 

(either user-set or automatic) and temperature choices are accounted for in the calculation. Some 

design options, such as reducing the amount of rinse water, have an efficiency benefit regardless 

of the user-set program. These and other design options have allowed the 3 highest-volume 

commercial clothes washer manufacturers to reach the 1.26 MEF standard level at relatively low 

cost by making evolutionary changes to their vertical-axis platforms. 

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EE-2006-STD-0127 COMMENT 39.2
For example, the calculated MEF is a function of the cycle water temperatures. By 

requiring a cold rinse and offering more warm or cold wash programs while reducing the number 

of hot wash cycle options, the MEF of a washer can be raised without affecting the WF. The 

incremental cost of offering more wash temperatures or lowering the temperatures overall is 

relatively minor. Similarly, the added cost and complexity of offering a water level selector 

switch is relatively minor but it allows manufacturers to take advantage of the credits that the 

DOE test procedure gives to washers that have this design option. 

At the time of the AHAM data submittal for the 2000 TSD, clothes washer manufacturers 

had little experience with the updated clothes washer test procedure, which was not published in 

the Federal Register until August 27, 2000. The only vertical-axis clothes washers on the market 

at the time that could reach an MEF of 1.26 were proprietary in design. Furthermore, the clothes 

washer manufacturing cost estimates for the 1.26 MEF levels were an amalgam of the high-cost 

proprietary vertical-axis design and several horizontal-axis washers. 

In conclusion, the cost of upgrading vertical-axis washers to reach an MEF of 1.26 was 

lower than manufacturers estimated according to the AHAM-supplied data. No expensive 

design options had to be employed to push the vertical-axis platform to that MEF level. 

Therefore, DOE believes that the current manufacturing cost of an agitator vertical-axis clothes 

washer which meets the 1.26 MEF/9.5 WF efficiency level is within 10 percent of the cost of a 

baseline washer in Table 5.6.33 once these costs are adjusted for inflation. 

Persistence of Baseline Vertical-Axis versus Horizontal-Axis Clothes Washer Cost 

Differential 

Since the publication of the 2000 TSD, the clothes washer market has been transformed 

by the entrance of more foreign competitors, significant market consolidation, and the 

appearance of residential clothes washers that have higher load capacities than the basketcapacity limits defined by EPACT 2005. For example, horizontal-axis residential clothes 

washers from BSH Home Appliances Corporation (Bosch-Siemens), GE, LG Electronics, Inc. 

(LG), and Whirlpool have a stated basket capacity in excess of the 3.5 cubic foot capacity 

product class definition limit set by EPACT 2005 for residential clothes washers. 

Despite the entrance of multiple horizontal-axis clothes washers into the commercial and 

residential markets, a significant retail price difference between agitator vertical- and horizontalaxis clothes washer platforms persists. This suggests that manufacturers have yet to overcome 

the inherently higher costs associated with manufacturing horizontal-axis clothes washer 

platforms. 

These cost differences are due in part to the suspensions, seals, drive systems, and 

stainless-steel wash baskets that horizontal-axis clothes washers employ and which can be 

simpler, unnecessary, and/or less expensive in baseline vertical-axis models. The higher 

strength, stiffness, and vibration-resistance requirements for horizontal-axis clothes washers add 

further cost and complexity. Electronic drive systems are found in all horizontal-axis clothes 

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EE-2006-STD-0127 COMMENT 39.2
washers, whereas simpler and less expensive induction motors are typically found on baseline 

vertical-axis clothes washers. 

High-volume manufacturers of vertical-axis clothes washers also benefit from a plant and 

equipment stock that have been largely depreciated, yet remain functional. The growth in 

horizontal-axis clothes washer sales continues to demand factory expansion and the resultant 

investments. 

As noted above, the reverse-engineering analysis of the 2000 residential clothes washer 

TSD is largely not a valid basis upon which to compare costs in the commercial market. 

However, it is interesting to note how manufacturers were able to meet the current 1.26 MEF 

residential clothes washer standard with little to no additional manufacturing cost. Thus, the cost 

of a baseline vertical-axis washer has not changed much in the interim, other than to reflect 

changes in raw materials costs. Horizontal-axis clothes washer costs are similarly affected, so 

that the manufacturing cost differential between the 2 residential clothes washer platforms has 

remained largely the same. 

The retail pricing survey for this current TSD underscores this persistent differential, as 

noted in Figure 3.11.1 in Chapter 3 of this TSD. This figure demonstrates that the average retail 

price difference between commercial top-loading, vertical-axis and front-loading, horizontal-axis 

washers varies between $531 for washers with coin boxes and $625 for washers without coin 

boxes. As noted in Table 8.2.42 in Chapter 8 of this TSD, the total markup from manufacturer to 

end user is 1.93 for commercial clothes washers. Therefore there is a manufacturing cost 

difference of $275 to $327 between vertical-axis and horizontal-axis commercial clothes washer 

platforms. 

This difference is about $100 higher than the average difference calculated in the 2000 

residential clothes washer TSD between baseline vertical-axis and 2 horizontal-axis clothes 

washers that were subjected to reverse-engineering analysis. However, the residential designs 

were produced at much a higher manufacturing scale, suggesting higher cost optimization, better 

purchasing power, and lower raw material costs. Higher-volume manufacturing allows a 

manufacturer to consider more platform and design options that could not be economically 

justified at a very low manufacturing scale. 

Thus, the $316 cost difference in the AHAM-submitted data for vertical-axis and 

horizontal-axis commercial clothes washers is plausible. A cost difference higher than that 

found in the residential market is reasonable since commercial clothes washers are designed to 

be more rugged, are required to be more reliable, and are produced at a much lower scale. As a 

consequence, manufacturers cannot readily cost-optimize horizontal-axis designs to the extent 

that they have been able to refine their extant vertical-axis units. In addition, even an optimized 

horizontal-axis commercial clothes washer will remain inherently more expensive to produce 

than a high-volume residential model built on the same platform due to the volume over which 

customized items like controllers have to be depreciated. 

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EE-2006-STD-0127 COMMENT 39.2
In determining incremental costs at intermediate efficiency levels other than those at 

which AHAM supplied data, DOE notes that, like dishwashers, CCWs are platform-driven 

products where platforms achieve an inherent efficiency based on design that can be further 

enhanced via design options. However, the cost of the CCW is the same to the manufacturer, 

whether it is programmed to operate at the inherent efficiency level, or below. Thus, DOE 

expects that the incremental costs between 1.60 MEF/8.5 WF and 2.2 MEF/5.1 WF would be 

constant at the same value as those provided by AHAM for the level 2.0 MEF/5.5 WF. 

Table 5.6.34 shows the preliminary commercial clothes washer cost-efficiency results. 

Table 5.6.34 Incremental Manufacturing Cost for Commercial Clothes Washers 

Efficiency Levels (MEF/WF) Incremental Cost 

Baseline -

1.42/9.5 $74.73 

1.60/8.5 $316.35 

1.72/8.0 $316.35 

1.80/7.5 $316.35 

2.00/5.5 $316.35 

2.20/5.1 $316.35 

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EE-2006-STD-0127 COMMENT 39.2
REFERENCES 

1 U.S. Department of Energy (DOE). 1996. Technical Support Document for Residential 

Cooking Products. Washington, DC. 

<http://www.eere.energy.gov/buildings/appliance_standards/residential/cooking_products_0998_r.html> 

2 A. P. Sanghvi, Cost-Benefit Analysis of Power System Reliability: Determination of 

Interruption Costs. Prepared by RCG/Hagler Bailly, Inc., Arlington, VA for Electric Power 

Research Institute, Palo Alto, CA, EL-6791. Vol. 2, p. 3-3 and Vol. 3, p. 3-3. 

<http://www.epri.com> 

3 American Metals Market, http://www.amm.com/. 

4 U.S. Department of Energy (DOE). 1997. Technical Support Document: Energy 

Conservation Standards for Consumer Products: Room Air Conditioners. Washington, DC, 

DOE/EE-O148, September 1997. 

5 Association of Home Appliance Manufacturers (AHAM). 2006. AHAM Test Data on 

Microwave Ovens. October 23, 2006. Docket No. EE-2006-STD-0127, Comment Number 

17. 

6 Ibid. 

7 Ibid. 

8 Ibid. 

9 Ibid. 

10 Ibid. 

11 Fish, N. et al. 2006. Standby Power Energy Use of Common Household Appliances. 

Canadian Building Energy End-Use Data and Analysis Centre, CBEEDAC 2006-RP-04-

DRAFT, July 2006. 

12 Aulenback, A. et al. 2001. Stand-By Power Requirements for Household Appliances. 

Canadian Residential Energy End-Use Data and Analysis Centre, CREEDAC-2001-05-04, 

May 2001. 

13 Ibid. 

14 Lawrence Berkeley National Laboratory (LBNL). 1999. Standby Power Summary Table. 

Available online at http://standby.lbl.gov/Data/SummaryTable.html. 

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EE-2006-STD-0127 COMMENT 39.2
15 Floyd, D. and Webber, C. 1998. “Leaking Electricity: Individual Field Measurement of 

Consumer Electronics”, Proceedings of American Council for an Energy-Efficient Economy, 

Florida Solar Energy Center, August 1998. 

16 Meier, A. and Huber, W. 1997. Results from the Investigations on Leaking Electricity in the 

USA. Lawrence Berkeley National Laboratory, Berkeley, CA, LBNL-40909, 1997. 

17 AHAM. 2006. Op. cit. 

18 U.S. Department of Energy (DOE). 1980. Engineering Analysis. Washington, DC, 

DOE/CS-1066, June 1980. 

19 Bloomfield Jr., W.E., President of WEB Service Company Inc., 2001. Testimony at the 

California Energy Commission (CEC) public hearing regarding the matter of AB970 

California Appliance Efficiency Regulations, CEC 4-24-2001 Hearing Record, April 24, 

2001, p. 138. 

20 Thompson, M., Whirlpool Corporation, 2001. Testimony at the CEC public hearing 

regarding the matter of AB970 California Appliance Efficiency Regulations, CEC 4-24-2001 

Hearing Record, April 24, 2001, p. 157. 

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