CHAPTER 4. SCREENING ANALYSIS 

TABLE OF CONTENTS 

4.1 INTRODUCTION ........................................................................................................... 4-1 

4.2 DISCUSSION OF TECHNOLOGY OPTIONS.............................................................. 4-1 

4.2.1 Screened-Out Technology Options.................................................................................. 4-2 

4.2.1.1 Gas Cooktops.................................................................................................4-3 

4.2.1.2 Electric Open (Coil) Cooktops....................................................................... 4-4 

4.2.1.3 Electric Smooth Cooktops ............................................................................. 4-5 

4.2.1.4 Electric and Gas Ovens.................................................................................. 4-5 

4.2.1.5 Microwave Ovens.......................................................................................... 4-7 

4.2.2 Remaining Design Options.............................................................................................. 4-7

4.2.2.1 Gas Cooktops.................................................................................................4-7 

4.2.2.2 Electric Open (Coil) Cooktops....................................................................... 4-8 

4.2.2.3 Electric Smooth Cooktops ............................................................................. 4-8 

4.2.2.4 Electric and Gas Ovens.................................................................................. 4-8 

4.2.2.5 Microwave Ovens.......................................................................................... 4-9 

LIST OF TABLES 

Table 4.2.1 Retained Design Options for Gas Cooktops ........................................................ 4-8 

Table 4.2.2 Retained Design Options for Electric Open (Coil) Element Cooktops ............... 4-8 

Table 4.2.3 Retained Design Options for Electric Smooth Element Cooktops ...................... 4-8 

Table 4.2.4 Retained Design Options for Electric and Gas Ovens......................................... 4-9 

Table 4.2.5 Retained Design Options for Microwave Ovens–Energy Factor ........................ 4-9 

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CHAPTER 4. SCREENING ANALYSIS 

4.1 INTRODUCTION 

This chapter discusses the screening analysis conducted by the U.S. Department of 

Energy (DOE) of the technology options identified in the market and technology assessment for 

residential cooking productsa (chapter 3 of this technical support document (TSD)). In the 

market and technology assessment, DOE presented an initial list of technology options that can 

be used to reduce energy consumption of each of the products covered in this rulemaking. The 

goal of the screening analysis is to identify any technologies that will be eliminated from further 

consideration in the rulemaking analyses. As described in section 1.3 of chapter 1 of this TSD, 

DOE is continuing the rulemaking for energy conservation standards for commercial clothes 

washers and microwave oven standby power, and analyses related to these products will be 

published in separate TSDs. 

For each product, the corresponding candidate technology options are assessed based on 

DOE analysis as well as inputs from interested parties, including manufacturers, trade 

organizations, and energy efficiency advocates. Technology options that are judged to be viable 

approaches for improving energy efficiency are retained as inputs to the subsequent engineering 

analysis, and are designated as design options. Technology options that are not incorporated in 

commercial products or in working prototypes, or that fail to meet certain criteria as to 

practicability 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: Procedures for Consideration of New or 

Revised Energy Conservation Standards for Consumer Products. 61 FR at 36974 (July 15, 

1996). The rationale for either screening out or retaining each technology option is detailed in 

the following sections. 

4.2 DISCUSSION OF TECHNOLOGY OPTIONS 

For residential cooking products, information used for applying the screening criteria to 

most of the technology options was derived from the previous rulemaking’s TSD, DOE’s 1996 

Technical Support Document for Residential Cooking Products (1996 TSD). The framework 

document for this rulemaking, entitled Rulemaking Framework for Commercial Clothes Washers 

and Residential Dishwashers, Dehumidifiers, and Cooking Products, March 15, 2006, describes 

which technology options DOE reevaluated for the engineering analysis in the current 

rulemaking. The approach proposed in the framework document for conventional cooking 

products is to retain the same screening results as put forth in the 1996 TSD. In addition, lowa

 The term “cooking products” refers to residential electric and gas kitchen ranges and ovens, including microwave 

ovens. The term “conventional cooking products” refers to cooking products other than microwave ovens. 

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EERE-2006-STD-0127 COMMENT 64.2
standby-loss electronics, which DOE identified for cooking products through literature searches 

and interested parties’ inputs, were evaluated. It should also be noted that radiant elements for 

smooth cooktops, which were included as a technology option in the 1996 TSD, were not 

included in the current rulemaking because manufacturer data provided to DOE for the 1996 

TSD indicated that this technology did not demonstrate an efficiency improvement over the 

baseline according to the DOE test procedure, and DOE is unaware of any more recent data that 

indicates otherwise. 

For microwave ovens, technology options from the 1996 TSD for improving energy 

factor (EF) were screened in the same manner as in the previous rulemaking. However, three 

additional technologies–—cooking sensors, dual magnetrons, and low-standby-loss electronic 

controls—were evaluated. DOE identified cooking sensors from product literature, while dual 

magnetrons were added based on information from the February 2006 edition of Appliance 

Design. DOE identified low-standby-loss electronic controls by reviewing the Association of 

Home Appliance Manufacturers (AHAM) data for standby power. 

4.2.1 Screened-Out Technology Options 

The following section details the specific technology options that were screened out prior 

to the engineering analysis, along with the rationale for elimination. 

The technologies identified in the market and technology assessment were evaluated 

pursuant to the criteria set out in the Energy Policy and Conservation Act (EPCA) for prescribing 

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. 6295(o)(2)(A)) It 

also establishes guidelines for determining whether a standard is economically justified. (42 

U.S.C. 6295(o)(2)(B)(i)) In view of the EPCA requirements for determining whether a standard 

is technologically feasible and economically justified, appendix A to subpart C of Title 10 Code 

of Federal Regulations part 430 (10 CFR part 430), Procedures, Interpretations and Policies for 

Consideration of New or Revised Energy Conservation Standards for Consumer Products (the 

“Process Rule”), sets forth procedures to guide DOE in the consideration and promulgation of 

new or revised product energy conservation standards under EPCA. These procedures elaborate 

on the statutory criteria provided in 42 U.S.C. 6295(o)(2) and, in part, eliminate problematic 

technologies early in the process of revising an energy conservation standard. Under the 

guidelines, before publishing an advance notice of proposed rulemaking (ANOPR), 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 

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EERE-2006-STD-0127 COMMENT 64.2
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 will 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 

results in the unavailability of any covered 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 technology options that were screened out for each 

product class covered by this rulemaking and the reasons why each were eliminated. 

4.2.1.1 Gas Cooktops 

For gas cooktops, DOE screened out catalytic burners, radiant gas burners, reduced 

excess air at burner, and reflective surfaces for the reasons that follow. 

Catalytic burners 

DOE is not aware of any commercialized catalytic burners for gas cooktops, so 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 time of the effective date of an amended 

standard. Also, because this technology is in the research stage, it is not possible to assess 

whether it will have any adverse impacts on utility to consumers or product availability, or any 

adverse impacts on consumers' health or safety. 

Radiant gas burners 

In the previous rulemaking, manufacturers asserted that the operating characteristics of an 

infrared (IR)-jet radiant burner are such that it is difficult to maintain a low burner input rate for 

many cooktop functions. They stated that field testing for residential ranges was discontinued 

because test users were unable to turn down the burner satisfactorily.1

 Without an adequate “turn 

down” capability, the burner would not be able to pass the American National Standards Institute 

(ANSI) Standard Z21.1-2005, Household Cooking Gas Appliances. 

Although a silicon carbide radiant burner has been tested to the Japanese Industrial 

Standard (JIS) S 2103:1996, Gas burning cooking appliances for domestic use, it is also not 

known how either type of radiant burner would perform under DOE test conditions. Since DOE 

lacks relevant test data to evaluate potential impacts on consumers’ health and safety, this 

technology option was not analyzed for gas cooktops. 

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Reduced excess air at burner 

For the 1996 TSD, the Gas Research Institute (GRI, now known as the Gas Technology 

Institute) submitted a report that analyzed this technology option and was submitted as a 

comment to the NOPR in the previous rulemaking.2

 GRI concluded that the efficiency increase 

of this technology option was not measurable at that time. They pointed out that the burner 

described by DOE did not exist on the market and thus there were no designs that could be 

evaluated. DOE is unaware of any changes to that situation. GRI also noted that use of this 

technology option may cause a safety issue due to the possibility of increased carbon monoxide 

production. 

Reduced excess air at the burner has not been commercialized, and 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 time of the effective date of an amended standard. 

Also, because this technology is undeveloped, it is not possible to assess whether it will have any 

adverse impacts on utility to consumers or product availability, or any adverse impacts on 

consumers' health or safety. . 

Reflective surfaces 

As reported in the 1996 TSD, manufacturers stated that any increase in efficiency due to 

a reflective surface could easily be negated if the consumer fails to regularly clean the surface or 

uses an abrasive pad to clean the surface. Therefore, it would be necessary to replace reflective 

pans periodically at a high replacement cost. Also, because this technology has not been 

commercialized, it is not possible to assess whether it will have any other adverse impacts on 

utility to consumers or product availability or any adverse impacts on consumers’ health or 

safety. 

4.2.1.2 Electric Open (Coil) Cooktops 

For electric open (coil) cooktops, DOE screened out reflective surfaces, for the reasons 

that follow. 

Reflective surfaces 

As reported in the 1996 TSD, manufacturers stated that any increase in efficiency due to 

a reflective surface could easily be negated if the consumer fails to regularly clean the surface or 

uses an abrasive pad to clean the surface. Therefore, it would be necessary to replace reflective 

pans periodically at a high replacement cost. Also, because this technology has not been 

commercialized, it is not possible to assess whether it will have any other adverse impacts on 

utility to consumers or product availability, or any adverse impacts on consumers’ health or 

safety. 

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4.2.1.3 Electric Smooth Cooktops 

For electric smooth cooktops, all technologies meet the screening criteria. 

4.2.1.4 Electric and Gas Ovens 

For electric and gas, DOE screened out added insulation, bi-radiant oven, halogen lamp 

oven, no oven door window, oven separator, reduced thermal mass, and reflective surfaces, for 

the reasons that follow. 

Added insulation 

Although some analyses indicated energy consumption could be reduced by increasing 

the thickness of the insulation in the cabinet walls and doors from 2 inches to 4 inches, consumer 

utility would be negatively impacted, since the oven cavity volume would have to be reduced to 

maintain standardized exterior dimensions. The reduced oven cavity volume would limit the size 

of large items that could be cooked in the oven. For this reason, this technology option was not 

analyzed. However, it should be noted that improved insulation, consisting of higher-density 

insulation with the baseline 2-inch thickness, was still analyzed for standard gas and electric 

ovens. This higher-density insulation is already used for self-clean gas and electric ovens. 

Bi-radiant oven (electric only) 

The 1996 TSD assumed that three major conditions would have to be met in order to 

consider the bi-radiant oven as a viable technology option. These included the use of (1) lowemissivity cavity lining materials; (2) electronic controls; and (3) highly-absorptive baking and 

roasting utensils. While electronic controls are currently in widespread use in electric ovens, 

cavity maintenance issues and the requirement for specialized cookware negatively impact 

consumer utility. In addition, there is currently no such product on the market and the last 

working prototype known to DOE was tested in the 1970s. 

Halogen lamp oven (electric only) 

While GE Consumer & Industrial (GE) currently markets a line of electric ovens that 

incorporates halogen elements along with conventional resistance heating elements, microwave 

heating, and a convection system, DOE is not aware of any ovens that utilize halogen lamps 

alone as the heating element, and no data were found or submitted to demonstrate how efficiently 

halogen elements alone perform relative to conventional ovens. DOE believes that it would not 

be practicable to manufacture, install and service halogen lamps for use in consumer cooking 

products on the scale necessary to serve the relevant market at the time of the standard’s 

effective date. 

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No oven door window 

GRI issued a topical report3 that discussed this technology option in the previous 

rulemaking. The report was submitted as a written comment to the associated NOPR. GRI’s 

experimental tests showed a small savings in annual energy usage (increase in efficiency) for 

both the standard and self-clean ovens by eliminating the door window. However, GRI reported 

there could actually be a net energy loss due to consumer practices, which would be a function of 

the number of times a consumer would open the door to inspect the food while cooking. With 

four door openings per test (per the DOE test procedure), a standard oven would realize a net 

energy savings of 34 thousand British thermal units per year (kBtu/yr). For a self-clean oven 

there is a net energy loss of 3 kBtu/yr. The report also stated there would be reduced consumer 

utility and the possibility of failure of delicate food items (e.g., soufflés), as well as decreased 

safety without the window due to increased risk of burns from additional door openings while 

the oven is in use. 

Oven separator 

U.S. manufacturers stated in the previous rulemaking that the use of an oven separator 

has been researched but has never been put into production because of problems it would cause 

both manufacturers and consumers. With regard to conventional gas ovens, manufacturers stated 

that the separator could not be economically designed for improved efficiency, though an 

acceptable design for gas convection ovens might be possible. With regard to electric ovens, 

manufacturers asserted that the separator would require the installation of an additional element 

and a non-conventional oven-control system. Manufacturers also stated that it would be difficult 

to obtain Underwriters Laboratory (UL) and American Gas Association (AGA) approvals and 

meet existing ANSI standards because of the effect the separator would have on safety and 

performance. Manufacturers further stated that consumer acceptance would probably be low 

because appliances such as microwave and toaster ovens already exist to cook small loads. In 

addition, the separator would have to be designed to be “fool-proof” to prevent consumers from 

accidentally installing it incorrectly. With regard to energy use, the additional metal added to the 

oven by the separator (increased thermal mass) might result in increased energy losses, although 

data provided by AHAM indicated an increase in efficiency of approximately 0.82 percentage 

points in an electric oven. However, the anticipated negative impacts on consumer utility and 

safety, along with practicability to manufacture, resulted in DOE screening out the oven 

separator from further analysis. 

Reduced thermal mass 

Manufacturers commented in the 1996 TSD that thermal mass reduction was not possible 

for then-manufactured electric and gas ovens. They stated that the oven walls must provide 

strong enough support to hold racks when baking heavy items (i.e., turkeys or large roasts.) 

Oven metal gauges could not be reduced any further without risking cracking and greater heat 

losses.4

 DOE believes this situation is still the case in current ovens. Due to issues of structural 

integrity during use and transportation as well as the issue of consumer product safety, this 

technology option was not analyzed. 

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EERE-2006-STD-0127 COMMENT 64.2
Reflective surfaces 

Manufacturers stated in the previous rulemaking that it has been very difficult to obtain 

satisfactory cooking performance with reflective surfaces. The reflective materials degrade after 

the first baking function and continue to degrade through the life of the product. This is 

especially true of self-cleaning ovens, as the self-cleaning process damages the reflective walls 

and negates any possible energy savings.5

 GRI6 performed tests on this technology option that measured a decrease in energy 

efficiency. The reflective surface interfered with the convective currents and the thermostat, thus 

fooling the thermostat into cycling. GRI reported that increased reflectance from the chromeplated inner surface of the oven caused repeated thermostat cycling that “might have contributed 

to the higher energy consumption” which resulted in a 12.61 percent decrease in energy 

efficiency. Arthur D. Little Inc. (ADL)7 also commented that the reflected radiation was 

different from the normal radiation emitted by the oven cavities in use at the time. 

Based on these studies, it is uncertain whether, or how much, energy savings is realizable 

with this technology option. A smarter controller for the oven could potentially compensate for 

the thermostat problems. However, there is a general lack of sophistication in the technology in 

terms of maintaining clean, reflective surfaces over the lifetime of the product. For these 

reasons, this technology option was not analyzed. 

4.2.1.5 Microwave Ovens 

For microwave ovens, all technologies which impact EF meet the screening criteria. 

4.2.2 Remaining Design Options 

The following sections list the technology options for each product class covered by this 

rulemaking that were retained by DOE and subsequently designated as design options. Each of 

these technologies were evaluated further in the subsequent engineering analysis. 

4.2.2.1 Gas Cooktops 

For gas cooktops, DOE retained the technologies listed below for further analysis. 

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Table 4.2.1 Retained Design Options for Gas Cooktops 

1. Electronic ignition 

2. Insulation 

3. Sealed burners 

4. Thermostatically controlled burners 

4.2.2.2 Electric Open (Coil) Cooktops 

For electric open (coil) cooktops, DOE considered the following design options for 

further analysis. 

Table 4.2.2 Retained Design Options for Electric Open (Coil) Element Cooktops 

1. Electronic controls 

2. Improved contact conductance 

3. Insulation 

4. Low-standby-loss electronic controls 

4.2.2.3 Electric Smooth Cooktops 

For electric smooth cooktops, DOE retained the following technologies for further 

analysis. 

Table 4.2.3 Retained Design Options for Electric Smooth Element Cooktops 

1. Electronic controls 

2. Halogen elements 

3. Induction elements 

4. Low-standby-loss electronic controls 

4.2.2.4 Electric and Gas Ovens 

For electric and gas ovens, DOE retained the following technologies for further analysis. 

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EERE-2006-STD-0127 COMMENT 64.2
Table 4.2.4 Retained Design Options for Electric and Gas Ovens 

1. Forced convection 

2. Improved door seals 

3. Improved insulation 

4. Low-standby-loss electronic controls 

5. Pilotless ignition (gas only) 

6. Radiant burner (gas only) 

7. Reduced conduction losses 

8. Reduced vent rate 

9. Steam cooking 

4.2.2.5 Microwave Ovens 

For microwave oven energy factor, DOE retained the technologies listed below for 

further analysis. 

Table 4.2.5 Retained Design Options for Microwave Ovens–Energy Factor 

1. Added insulation 

2. Cooking sensors 

3. Dual magnetrons 

4. Eliminate or improve ceramic stirrer cover 

5. Improved fan efficiency 

6. Improved magnetron efficiency 

7. Improved power supply efficiency 

8. Low-standby-loss electronic controls 

9. Modified wave guide 

10. Reflective surfaces 

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REFERENCES 

1 U.S. Department of Energy (U.S. DOE). 1998. Technical Support Document: Energy 

Conservation Standards for Consumer Products: Cooking Products, Washington, DC, 

September, 1998. 

2 Gas Research Institute (GRI). 1994. Topical Report: Technical Input to NAECA 

Rulemaking for Gas-Fired Ranges. Prepared by Battelle, Columbus, OH, American Gas 

Association Laboratories, Cleveland, OH, and Arthur D. Little, Cambridge, MA for Gas 

Appliance Technology Center, Chicago, IL, submitted as comment No. 001 to the NOPR, 

GRI-94/0195, July 1994. 

3 Ibid. 

4 U.S. DOE. 1998. Op. cit. 

5 Ibid. 

6 GRI. 1994. Op. cit. 

7 Arthur D. Little Inc. (ADL). 1994. Electric Oven and Cooktop Data Analysis. Prepared 

by ADL, Cambridge, MA, for Association of Home Appliance Manufacturers, Reference 

47066, submitted as comment No. 001 to the NOPR, July 15, 1994. 

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