CHAPTER 4. SCREENING ANALYSIS 

TABLE OF CONTENTS 

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

4.2 SCREENED-OUT TECHNOLGIES............................................................................... 4-2

4.2.1 General Service Fluorescent Lamp Screened-Out Technologies ........................4-2

4.2.1.1 Multi-Photon Phosphors .......................................................................... 4-2

4.2.2 Incandescent Reflector Lamp Screened-Out Technologies.................................4-2

4.2.2.1 Microcavity Filaments ............................................................................. 4-2

4.2.2.2 Novel Filament Materials ........................................................................ 4-3

4.2.2.3 Crystallite Filament Coatings .................................................................. 4-3

4.2.2.4 Luminescent Gas...................................................................................... 4-4

4.2.2.5 Non-Tungsten-Halogen Regenerative Cycles..........................................4-4

4.2.2.6 Infrared Phosphor Glass Coating.............................................................4-4

4.2.2.7 Trihedral Corner Reflectors ..................................................................... 4-5

4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED OUT.................................. 4-5

4.4 REMAINING TECHNOLOGIES ................................................................................... 4-6

4.4.1 General Service Fluorescent Lamps Design Options .......................................... 4-6

4.4.2 Incandescent Reflector Lamps Design Options................................................... 4-6

REFERENCES ............................................................................................................................4-8

LIST OF TABLES 

Table 4.3.2 IRL Technology Options Screened Out of the Analysis .............................4-6

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CHAPTER 4. SCREENING ANALYSIS 

4.1 INTRODUCTION 

This chapter discusses the U.S. Department of Energy’s (DOE) screening analysis 

of the technology options identified for general service fluorescent lamps (GSFL) and 

incandescent reflector lamps (IRL). As discussed in chapter 3, the Market and 

Technology Assessment, DOE consults with industry, technical experts, and other 

interested parties in developing a list of technology options for consideration. The 

purpose of the screening analysis is to evaluate the list of options to determine which to 

consider further and which to screen out. 

Section 325(o)(2) of EPCA provides that any new or revised standard must be 

designed to achieve the maximum improvement in energy efficiency that is determined to 

be technologically feasible and economically justified. (42 U.S.C. 6295(o)(2)) 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 its consideration and 

promulgation of new or revised efficiency standards. These procedures elaborate on the 

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

technologies early in the process of prescribing or amending an energy efficiency 

standard. In particular, sections 4(b)(4) and 5(b) of the Process Rule provide guidance to 

DOE for determining which design options are unsuitable for further consideration: 

1. Technological feasibility. DOE will consider technologies incorporated in 

commercial products or in working prototypes to be technologically feasible. 

2. Practicability to manufacture, install, and service. If mass production and 

reliable installation and servicing of a technology in commercial products could 

be achieved on the scale necessary to serve the relevant market at the time the 

standard comes into effect, then DOE will consider that technology practicable to 

manufacture, install, and service. 

3. Adverse impacts on product utility or product availability. If DOE 

determines a technology would have significant adverse impact on the utility of 

the product to significant subgroups of consumers, or would result in the 

unavailability of any covered product type with performance characteristics 

(including reliability), features, sizes, capacities, and volumes that are 

substantially the same as products generally available in the United States at the 

time, it will not consider this technology further. 

4. Adverse impacts on health or safety. If DOE determines that a technology will 

have significant adverse impacts on health or safety, it will not consider this 

technology further. 

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Section 4.2 discusses the technology options DOE screened out from further 

consideration. Section 4.3 summarizes those options. Section 4.4 lists the remaining 

design options DOE considered in its analyses. 

4.2 SCREENED-OUT TECHNOLGIES 

This section addresses the technologies that DOE screened out, having considered 

the following four factors: (1) technological feasibility; (2) practicability to manufacture, 

install, and service; (3) adverse impacts on product utility to consumers; and (4) adverse 

impacts on health or safety. 

4.2.1 General Service Fluorescent Lamp Screened-Out Technologies 

DOE has screened out the following technologies in its analyses of GSFL. 

Although these technologies were not considered in the subsequent analyses, DOE does 

not discourage their use by manufacturers. These technologies may be capable of 

reducing energy consumption or providing additional benefits to consumers, even though 

they do not currently meet the requirements for DOE’s consideration. 

4.2.1.1 Multi-Photon Phosphors 

Theoretically, the use of multi-photon phosphors, or quantum-splitting phosphors, 

could significantly improve lamp efficacy. By emitting more than one visible photon for 

each ultraviolet photon, a lamp would be able to emit more light for the same amount of 

power. However, development of this technology remains in the research phase and 

DOE is unaware of any prototypes or commercialized products that incorporate multiphoton phosphors.1

 Thus, DOE screened out this technology option based on the first 

criterion, technological feasibility. Additionally, because this technology is still in the 

research phase, DOE believes that it would not be practicable, or even possible, 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. It is not 

possible to assess whether the technology will have adverse impacts on utility to 

consumers, availability, or consumer health or safety. Therefore, DOE will not consider 

multi-photon phosphors as a design option for improving the efficacy of GSFL. 

4.2.2 Incandescent Reflector Lamp Screened-Out Technologies 

DOE screened out the following technologies for IRL. Although DOE did not 

consider the following technologies, DOE does not discourage their use since they may 

reduce energy consumption or provide other benefits to consumers. 

4.2.2.1 Microcavity Filaments 

By fabricating microcavities on the incandescent lamp filament, it is theoretically 

possible to increase a lamp’s emissivity, and therefore its efficacy. The market and 

technology assessment (chapter 3) notes that Sandia National Laboratories researchers 

examined microcavity resonance in a tungsten photonic lattice and DOE found multiple 

4-2
patents referencing this technology. Since research prototypes of microcavity filaments 

do exist, DOE determined that this technology option is technologically feasible. 

However, research indicates that materials patterned at the submicron level may 

experience problems with stability.2

 Because such instability could negatively affect 

lamp lifetime, DOE believes the technology is not yet practical to implement on a large 

scale. For this reason, DOE screened out this technology option based on the third 

criterion, impacts on product utility to consumers. DOE is also unaware of any 

commercialized lamps that incorporate microcavity filaments, and is concerned that 

mass-manufacturing techniques for this technology would be problematic. For this 

reason, DOE does not believe that this technology would be practicable to manufacture, 

install, and service. Therefore, DOE will not consider filaments with microcavities as a 

design option for improving the efficacy of IRL. DOE does not have enough information 

to assess whether implementation of this technology will have adverse impacts on 

consumer health or safety. 

4.2.2.2 Novel Filament Materials 

Novel filament materials such as nitrides and carbides have the potential to 

improve lamp efficacy by emitting more light in the visible spectrum at a given 

temperature than traditional tungsten filaments. Because several patents on such 

filaments exist, DOE believes that this technology option is technologically feasible. 

However, DOE is unaware of any lamps available today that use such filaments. 

Furthermore, DOE understands that technological barriers, such as prohibitive brittleness 

of the filament, limit implementation of this technology. Finding a practical way to 

incorporate novel filament materials into IRL would require further research, as would 

making such lamps practical for general service applications. DOE believes that it would 

not be practicable to manufacture this technology on the scale necessary to serve the 

relevant market at the time of the effective date of an amended standard. Therefore, DOE 

will not consider novel filament materials as a design option for improving the efficacy of 

IRL. DOE is unaware of any research on the potential impact of this technology on 

consumer health or safety. 

4.2.2.3 Crystallite Filament Coatings 

DOE screened out crystallite filament coatings, which are oxide-covered micron 

or sub-micron crystallites comprised of thorium, tantalum, or niobium. These coatings 

can be used to increase the light emissivity of a lamp’s filament. Because several patents 

on such filament coatings exist, DOE believes that this technology option is 

technologically feasible. However, DOE was unable to locate any data on the 

incorporation of crystallite filament coatings into prototype or commercially available 

products. Using crystallite filament coatings may require additional manufacturing 

techniques, such as chemical vapor deposition. DOE understands that these techniques 

are not in use in the mass-production of IRL. DOE believes that it would not be 

practicable to manufacture this technology on the scale necessary to serve the relevant 

market of IRL at the time of the effective date of an amended standard. DOE screened 

out this option based on the second criterion. It is also not possible to assess whether this 

technology will have adverse impacts on utility to consumers, availability, or consumer 

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health or safety. Therefore, DOE will not consider crystallite filament coatings as a 

design option for improving the efficacy of IRL. 

4.2.2.4 Luminescent Gas 

Luminescent gases encompass gaseous fills for incandescent lamps that react with 

certain wavelengths of the filament emission and generate visible light. DOE is unaware 

of any existing commercially available products or prototypes of incandescent lamps 

incorporating luminescent gases. DOE screened out luminescent gases based on 

technological feasibility. To the best of DOE’s knowledge, luminescent gas fills also 

have not been incorporated into residential, commercial, or industrial products, so DOE 

cannot assess the practicability 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. It is not possible to assess whether this technology will have adverse 

impacts on utility to consumers, availability, or consumer health or safety. Therefore, 

DOE will not consider luminescent gas fills as a design option for improving the efficacy 

of IRL. 

4.2.2.5 Non-Tungsten-Halogen Regenerative Cycles 

The regenerative cycle of filament evaporation and redeposition can be used to 

greatly increase the life of an incandescent lamp and improve lumen maintenance. The 

filament can burn at a higher temperature than conventional incandescent lamps while 

maintaining a useful service life. The market and technology assessment (chapter 3) 

discusses the use of a regenerative cycle for tungsten-halogen lamps. DOE understands 

that other regenerative cycles also may be possible for other filament materials and are 

considered technologically feasible. However, as noted above, DOE has screened out the 

use of novel filament materials on the basis of the second and third screening criteria. 

Because use of the non-tungsten-halogen regenerative cycles would depend on 

incorporating a non-tungsten filament, DOE is screening out such cycles from 

consideration based on the same two criteria. DOE believes that it would not be 

practicable, and maybe not even possible, to manufacture novel filament materials lamps 

with associated regenerative cycles on the scale necessary to serve the relevant market at 

the time of the effective date of an amended standard. Also, the use of other filament 

materials, and therefore their associated regenerative cycles, may have an adverse impact 

on utility. In addition, because this technology has not been incorporated into 

commercially available products, DOE is unable to assess whether it will have adverse 

impacts on consumer health or safety. Therefore, DOE will not consider non-tungstenhalogen regenerative cycles as a design option for improving the efficacy of IRL. 

4.2.2.6 Infrared Phosphor Glass Coating 

When used as a coating on the bulb surface, infrared phosphors harvest the 

emitted infrared energy and convert it to visible light, potentially increasing lamp 

efficacy. Because patents on such infrared phosphor coatings exist, DOE believes that 

this technology option is technologically feasible. However, DOE was unable to locate 

any data on the incorporation of infrared phosphor coatings into commercially available 

4-4
products. Because using infrared phosphor coatings in IRL may require retooling of the 

manufacturing process, DOE believes that it would not be practicable to manufacture this 

technology on the scale necessary to serve the relevant market at the time of the effective 

date of an amended standard. Therefore, DOE screened out this option based on the 

second criterion. It is also impossible to assess whether the technology will have adverse 

impacts on utility to consumers, availability, or consumer health or safety. Therefore, 

DOE will not consider infrared phosphor coatings as a design option for improving the 

efficacy of IRL. 

4.2.2.7 Trihedral Corner Reflectors 

Trihedral corner reflectors incorporated into the cover glass of IRL have the 

potential to increase lamp efficacy by redirecting infrared radiation back onto the 

filament. Because patents on trihedral corner reflectors exist, DOE believes that this 

technology option is technologically feasible. However, DOE was unable to locate any 

data on the incorporation of this technology into commercially available products. Using 

trihedral corner reflectors, which entail an additional disc requiring external fabrication 

and installation in the lamp, may necessitate manufacturing techniques not currently 

available for mass production. For this reason, DOE believes that it would not be 

practicable to implement the new manufacturing technique for this technology on the 

scale necessary to serve the relevant market of IRL at the time of the effective date of an 

amended standard. Therefore, DOE screened out this option based on the second 

criterion. It is not possible to assess whether the technology will have adverse impacts on 

utility to consumers, availability, or consumer health or safety. Therefore, DOE will not 

consider trihedral corner reflectors as a design option for improving the efficacy of IRL. 

4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED OUT 

The following tables summarize the technology options DOE screened out from

further consideration and note the screening criteria. 

Table 4.3.1 GSFL Technology Options Screened Out of the Analysis

Design Option Excluded Screening Criteria 

Multi-Photon Phosphors Technological feasibility 

Practicability to manufacture, install, and service 

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Table 4.3.2 IRL Technology Options Screened Out of the Analysis

Design Option Excluded Screening Criteria 

Microcavity Filaments Product utility to consumers 

Practicability to manufacture, install, and service 

Novel Filament Materials Practicability to manufacture, install, and service; product 

utility to consumers 

Crystallite Filament Coatings Practicability to manufacture, install, and service 

Luminescent Gas Technological feasibility 

Non-Tungsten-Halogen Regenerative 

Cycles 

Practicability to manufacture, install, and service 

Product utility to consumers 

Infrared Phosphor Glass Coating Practicability to manufacture, install, and service 

Trihedral Corner Reflectors Practicability to manufacture, install, and service 

4.4 REMAINING TECHNOLOGIES 

After screening out those technologies in accordance with the policies set forth in 

10 CFR Part 430, Subpart C, Appendix A, (4)(a)(4) and 5(b), DOE is considering the 

design options in the following list as viable means for improving efficacy. The market 

and technology assessment (chapter 3) provides a detailed description of these design 

options. 

4.4.1 General Service Fluorescent Lamps Design Options 

 Highly Emissive Electrode Coatings 

 Higher-Efficiency Lamp Fill Gas Composition 

 Higher-Efficiency Phosphors 

 Glass Coatings 

 Higher-Efficiency Lamp Diameter 

4.4.2 Incandescent Reflector Lamps Design Options 

 Higher-Temperature Operation 

 Thinner Filaments 

 Efficient Filament Coiling 

 Efficient Filament Orientation 

 Higher-Efficiency Inert Fill Gas 

 Tungsten-Halogen Lamps 

 Higher-Pressure Tungsten Halogen Lamps 

 Infrared Glass Coatings (thin-film) 

 Higher-Efficiency Reflector Coatings 

 Integrally-Ballasted Low-Voltage Lamps 

 Efficient Filament Placement 

 DOE will consider these options in the engineering analysis. As discussed in 

chapter 5, DOE based its engineering analysis to the greatest extent possible on 

commercially available products, which incorporate one or more of these design options. 

4-6
By doing this, DOE uses catalog data to determine both prices and performance attributes 

more efficacious lamps. 

4-7
4-8

 

REFERENCES 

1

 U.S. Department of Energy Office of Building Technologies. U.S. Lighting Market 

Characterization, Volume II: Energy Efficient Lighting Technology Options. September, 

2005. (Last accessed July 1, 2009). 

< http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/ee_lighting_vol2.pdf> 

2 Ibid.