4

- i CHAPTER 4

. SCREENING ANALYSIS

TABLE OF CO NTENTS

4.1 INTRODUCTION

................................ ................................ ................................ ........... 4

- 1

4.2 DISCUSSION OF DESIGN OPTIONS

................................ ................................ .......... 4

- 1

4.2.1 Screened

- Out Design Options

................................ ................................ .......................... 4

- 1

4.2.2 Remaining Des ign Options

................................ ................................ .............................. 4

- 3

LIST OF TABLES

Table 4.2.1 Retained Design Options for Dishwashers

................................ .............................. 4

- 34-1 CHAPTER 4. SCREENING ANALYSIS

4.1 INTRODUCTION

This chapter discusses the screening analysis conducted by the U.S. Department of Energy (DOE) of the design options identified in the market and technology assessment for

residential dishwashers ( c hapter 3 of th is direct final rule technical support document (TSD)) . In the market and technology assessment, DOE presented an initial list of technologies, or design option s that can be used to reduce energy and/or water consumption for residential dishwashers

. The goal of the screening analysis is to identify any design options that will be eliminated from further consideration in the rulemaking analyses.

The c andidate de sign options are assessed based on DOE analysis as well as inputs from interested parties including manufacturers, trade organizations, and energy efficiency advocates. Design options that are judged to be viable approaches for improving energy efficiency are retained as inputs to the subsequent e ngineering a nalysis. Design options which are not incorporated in commercial products or in working prototypes, or that fail to meet certain crit eria as to practi ca bility to manufacture, install and service, as to impacts on product utility or availability, or as to health or safety will be eliminated from consideration in accordance with Energy Conservation Program for Consumer Products: Procedur es for Consideration of New or Revised Energy Conservation Standards for Consumer Products

. ( 61 FR 36974, section 4(a)(4) and 5(b) ) . The rationale for either screening out or retaining each design option is detailed in the following sections.

4.2 DISCUSSION OF DESIGN OPTIONS

For residential dishwashers

, the screening criteria specified in section 4.1 were applied to the design options to either retain or eliminate each technology from the engineering analysis.

4.2.1 Screened

- Out Design Opt ions

The technologies identified in the market and technology assessment were evaluated pursuant to the criteria set out in The Energy Policy and Conservation Act, as amended (EPCA or the Act). ( 42 U.S.C. 6 291

– 63 09 ) EPCA provides criteria for prescribin g new or amended standards, which will achieve the maximum improvement in energy efficiency the Secretary of Energy determines is technologically feasible. (42 U.S.C. 6 295 ( o )( 2 )(A)) It also establishes guidelines for determining whether a standard is ec onomically justified. (42 U.S.C.

6 295 ( o )( 2 )(B)) In view of the EPCA requirements for determining whether a standard is technologically feasible and economically justified, a ppendix A to subpart C of Title 10 Code of Federal Regulations p art 430 (10 CFR p art 430), Procedures, Interpretations and Policies for Consideration of New or Revised Energy Conservation Standards for Consumer Products (the4-2 “ Process Rule ” ), sets forth procedures to guide DOE in the consideration and promulgation of new or revised product efficiency standards under EPCA. These procedures elaborate on the statutory criteria provided in 42 U.S.C. 6 295 and in part eliminate problematic techno logies early in the process of revising an energy efficiency standard. Under the guidelines, DOE eliminates from consideration technologies that present unacceptable problems with respect to the following

four factors:

(1) Technological feasibility. If it is determined that a technology has not been incorporated in commercial products or in working prototypes, then that technology will not be

considered further.

(2) Practicability to manufacture, install, and service. If it is determined that mass production of a technology in commercial products and reliable installation and servicing of the technology could not be achieved on the scale necessary to serve the relevant market at the time of the effective date of the standard, then that technology w ill not be considered further.

(3) Impacts on product utility to consumers. If a technology is determined to have significant adverse impact on the utility of the product to significant subgroups of consumers, or

result s in the unavailability of any co vered product type with performance characteristics (including reliability), features, size, capacities, and volumes that are substantially the same as products generally available in the United States at the time, it will not be considered further.

(4 ) Safety of technologies. If it is determined that a technology will have significant adverse impacts on health or safety, it will not be considered further.

The following sections detail the design options that were screened out for this rulemaking

, and the reasons why they were eliminated.

Reduced inlet

- water temperature

Reduced inlet

- water temperature requires that dishwashers tap the cold water line for their water supply. Because most dishwashers in the United States tap the hot water line, t his design option would require significant alteration of existing dishwasher installations in order to accommodate newly purchased units incorporating this design option . Therefore, DOE believes that it would not be practicable to install this technology on the scale necessary to serve the

relevant market at the time of the effectiv e date of an amended standard.

Supercritical carbon dioxide washing

Supercritical carbon dioxide washing , which uses supercritical carbon dioxide instead of conventional detergent and water to wash dishes

, is currently being researched. Thus, DOE believes that it would not be practicable to manufacture, install and service this technology on the scale necessary to serve the relevant market at the t ime of the effective date of an amended

standard. Furthermore , because this technology is in the research stage, it is not yet possible to4-3 assess whether it will have any adverse impacts on equipment utility to consumers or equipment availability, or any adverse impacts on consumers' health or safety.

Ultrasonic washing

A dishwasher using ultrasonic waves to generate a cleaning mist has been demonstrated. However, this model did not use ultrasonic waves in a standing fluid to clean dishes, and

additiona lly relied on ion generation for further cleaning. Ultrasonic dishwashing based upon

soiled

- dish immersion in a fluid which is then excited by ultrasonic waves has not been

demonstrated. In an immersion

- based ultrasonic dishwasher, standing ultrasonic wa ves within the washing cavity and the force of bubble cavitation implosion can damage fragile dishware. The low water temperatures utilized by ultrasonic dishwashers may also lead to a perceived decrease in consumer utility, since consumers expect hot wat er in the dishwa sher to sterilize

dishes. Because no manufacturer currently produce ultrasonic dishwashers in the United States

, it is impossible to assess whether this design option would have any impacts on consumer s’ health or safety, or product availa bility.

4.2.2 Remaining Design Options

The following sections list the design options for each product covered by this rulemaking that were retained by DOE . Each of these technologies will be evaluated further in the subsequent engineering analysis.

For dishwa shers , DOE will consider the design options shown in Table 4.2

. 1 for further analysis.

Table 4.2

. 1 Retained Design Options for Dishwashers

1. Condenser drying

2. Control s trategies

3 . Fan/jet drying

4 . Flow

- through heating

5 . Improved fill control

6 . Improved food filter

7 . Improved motor efficiency

8 . Improved spray

- arm geometry

9 . Increased insulation

10

. Low

- standby

- loss electronic controls

11

. Microprocessor controls and fuzzy logic, including adaptive or soil

sensing controls

12 . Modified sump geometry, with and without dual pumps

13

. Variable washing pressures and flow rates