5-i 

CHAPTER 5. ENGINEERING ANALYSIS 

 

TABLE OF CONTENTS 

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

5.2 METHODOLOGY OVERVIEW .................................................................................... 5-1

5.3 GENERAL SERVICE FLUORESCENT LAMPS .......................................................... 5-2

5.3.1 Representative Product Classes ........................................................................... 5-2

5.3.2 Baseline Lamps .................................................................................................... 5-3

5.3.3 More Efficacious Substitutes ............................................................................... 5-4

5.3.4 Candidate Standard Levels .................................................................................. 5-4

5.3.5 GSFL Systems ..................................................................................................... 5-5

5.3.5.1 Ballast Selection .................................................................................... 5-6

5.3.5.2 System Input Power Calculation ........................................................... 5-9

5.3.6 Engineering Results by Representative Product Classes ................................... 5-11

5.3.6.1 Four-Foot MBP GSFLs with CCTs ≤ 4,500 K ................................... 5-11

5.3.6.2 Eight-Foot SP Slimline GSFLs with CCTs ≤ 4,500 K ........................ 5-22

5.3.6.3 Eight-Foot RDC HO GSFLs with CCTs ≤ 4,500 K ............................ 5-28

5.3.6.4 Four-Foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 K.................... 5-33

5.3.6.5 Four-Foot T5 MiniBP HO GSFLs with CCTs ≤ 4,500 K ................... 5-39

5.3.7 Scaling to Product Classes Not Analyzed .......................................................... 5-45

5.3.7.1 2-foot U-Shaped GSFLs with CCTs ≤ 4,500 K .................................. 5-45

5.3.7.2 Lamps with CCTs Above 4,500 K ...................................................... 5-45

5.3.8 Summary of All Candidate Standard Levels for Covered GSFLs ..................... 5-46

5.4 INCANDESCENT REFLECTOR LAMPS ................................................................... 5-47

5.4.1 Representative Product Classes ......................................................................... 5-47

5.4.2 Baseline Lamps .................................................................................................. 5-47

5.4.3 More Efficacious Substitutes ............................................................................. 5-48

5.4.4 Candidate Standard Levels ................................................................................ 5-48

5.4.5 Scaling to Product Classes Not Analyzed .......................................................... 5-52

5.4.5.1 Modified Spectrum .............................................................................. 5-52

5.4.5.2 Diameters Less Than or Equal To 2.5 Inches ..................................... 5-53

5.4.5.3 Operating Voltages Greater Than or Equal to 125 Volts .................... 5-54

5.4.6 Summary of All Candidate Standard Levels for Covered IRLs ........................ 5-55

REFERENCES .......................................................................................................................... 5-56

LIST OF FIGURES 

Figure 5.3.1 Candidate Standard Levels for 4-foot MBP GSFLs with CCTs ≤ 4,500 K .......... 5-13

Figure 5.3.2 All Compliance Report Data for 4-foot MBP GSFLs with CCTs ≤ 4,500 K ....... 5-14

Figure 5.3.3 Candidate Standard Level for 8-foot SP Slimline GSFLs with CCTs ≤ 4,500 K . 5-23

Figure 5.3.4 All Compliance Report Data for 8-foot SP Slimline GSFLs with CCTs ≤ 4,500 K . 5-

25

Figure 5.3.5 Candidate Standard Level for 8-foot RDC HO GSFLs with CCTs ≤ 4,500 K ..... 5-29
5-ii

Figure 5.3.6 All Compliance Report Data for 8-foot RDC HO GSFLs with CCTs ≤ 4,500 K . 5-30

Figure 5.3.7 Candidate Standard Level for 4-foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 K, 

at 35 °C ...................................................................................................................................... 5-35

Figure 5.3.8 All Compliance Report Data for 4-foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 

K, at 25 °C ................................................................................................................................. 5-36

Figure 5.3.9 Candidate Standard Level for 4-foot T5 MiniBP HO GSFLs with CCTs ≤ 4,500 K, 

at 35 °C ...................................................................................................................................... 5-41

Figure 5.3.10 All Compliance Report Data for 4-foot T5 MiniBP HO GSFLs with CCTs ≤ 4,500 

K, at 25 °C ................................................................................................................................. 5-42

Figure 5.4.1 Initial Candidate Standard Level for Standard Spectrum, Large Diameter, Low 

Voltage IRLs .............................................................................................................................. 5-50

Figure 5.4.2 Compliance Report Data for Standard Spectrum, Large Diameter, Low Voltage 

IRLs............................................................................................................................................ 5-51

LIST OF TABLES 

Table 5.3.1 Representative Product Classes for General Service Fluorescent Lamps ................ 5-3

Table 5.3.2 GSFL Baseline Lamps .............................................................................................. 5-4

Table 5.3.3 Representative Lamp-and-Ballast System Pairings .................................................. 5-8

Table 5.3.4 High Frequency Reference Lamp Arc Powers ......................................................... 5-9

Table 5.3.5 Baseline Lamp for the 4-foot MBP Representative Product Class ......................... 5-12

Table 5.3.6 4-foot MBP Representative Lamps ......................................................................... 5-13

Table 5.3.7 CSL 1 and CSL 2 for 4-foot MBP GSFLs with CCTs ≤ 4,500 K .......................... 5-15

Table 5.3.8 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 32 W T8, 

4,100 K System in the Commercial and Industrial Sectors ....................................................... 5-16

Table 5.3.9 Lamp Replacement Engineering Analysis for a Two-Lamp Programmed Start 32 W 

T8, 4,100 K System in the Commercial and Industrial Sectors ................................................. 5-17

Table 5.3.10 Lamp Replacement Engineering Analysis for a Four-Lamp Instant Start 32 W T8, 

4,100 K System in the Commercial and Industrial Sectors ....................................................... 5-17

Table 5.3.11 Lamp Replacement Engineering Analysis for a Four-Lamp Programmed Start 32 W 

T8, 4,100 K System in the Commercial and Industrial Sectors ................................................. 5-17

Table 5.3.12 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 32 W T8, 

4,100 K System in the Residential Sector .................................................................................. 5-18

Table 5.3.13 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 

32 W T8, 4,100 K System in the Commercial and Industrial Sectors ....................................... 5-19

Table 5.3.14 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp 

Programmed Start 32 W T8, 4,100 K System in the Commercial and Industrial Sectors ......... 5-19

Table 5.3.15 Lamp-and-Ballast Replacement Engineering Analysis for a Four-Lamp Instant Start 

32 W T8, 4,100 K System in the Commercial and Industrial Sectors ....................................... 5-20

Table 5.3.16 Lamp-and-Ballast Replacement Engineering Analysis for a Four-Lamp 

Programmed Start 32 W T8, 4,100 K System in the Commercial and Industrial Sectors ......... 5-20

Table 5.3.17 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 

32 W T8, 4,100 K System in the Residential Sector ................................................................. 5-21

Table 5.3.18 Baseline Lamp for the 8-foot SP Slimline Representative Product Class ............ 5-22

Table 5.3.19 8-foot SP Slimline Representative Lamps ............................................................ 5-24

Table 5.3.20 CSL 1 for 8-foot SP Slimline GSFLs with CCTs ≤ 4,500 K ................................ 5-25
5-iii

Table 5.3.21 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 59 W T8, 

4,100 K System in the Commercial and Industrial Sectors ....................................................... 5-26

Table 5.3.22 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 

59 W T8, 4,100 K System in the Commercial and Industrial Sectors ....................................... 5-27

Table 5.3.23 Baseline Lamp for the 8-foot RDC HO Representative Product Class ................ 5-28

Table 5.3.24 8-foot RDC HO Representative Lamps ................................................................ 5-29

Table 5.3.25 CSL 1 for 8-foot RDC HO GSFLs with CCTs ≤ 4,500 K .................................... 5-30

Table 5.3.26 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 86 W T8, 

4,100 K System in the Commercial and Industrial Sectors ....................................................... 5-31

Table 5.3.27 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 

86 W T8, 4,100 K System in the Commercial and Industrial Sectors ....................................... 5-32

Table 5.3.28 Baseline Lamp for the 4-foot T5 MiniBP Standard Output Representative Product 

Class ........................................................................................................................................... 5-33

Table 5.3.29 4-foot T5 MiniBP SO Representative Lamps ....................................................... 5-35

Table 5.3.30 CSL 1 for 4-foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 K........................... 5-36

Table 5.3.31 Lamp Replacement Engineering Analysis for a Two-Lamp Programmed Start 28 W 

T5, 4,100 K System in the Commercial and Industrial Sectors ................................................. 5-37

Table 5.3.32 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp 

Programmed Start 28 W T5, 4,100 K System in the Commercial and Industrial Sectors ......... 5-38

Table 5.3.33 Baseline Lamp for the 4-foot T5 MiniBP High Output Representative Product Class

.................................................................................................................................................... 5-39

Table 5.3.34 4-foot T5 MiniBP HO Representative Lamps ...................................................... 5-41

Table 5.3.35 CSL 1 for 4-foot T5 MiniBP HO GSFLs with CCTs ≤ 4,500 K .......................... 5-42

Table 5.3.36 Lamp Replacement Engineering Analysis for a Two-Lamp Programmed Start 54 W 

T5, 4,100 K System in the Commercial and Industrial Sectors ................................................. 5-43

Table 5.3.37 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp 

Programmed Start 54 W T5, 4,100 K System in the Commercial and Industrial Sectors ......... 5-44

Table 5.3.38 Efficacy Requirements for 2-foot U-Shaped Lamps with CCTs Less Than or Equal 

To 4,500 K ................................................................................................................................. 5-45

Table 5.3.39 Efficacy Requirements for Product Classes with CCTs Greater Than 4,500 K ... 5-46

Table 5.3.40 Summary of All Candidate Standard Levels for Covered GSFLs ........................ 5-46

Table 5.4.1 Product Classes for Incandescent Reflector Lamps ................................................ 5-47

Table 5.4.2 IRL Baseline Lamps ............................................................................................... 5-48

Table 5.4.3 IRL Representative Lamps ..................................................................................... 5-50

Table 5.4.4 CSL 1 for Standard Spectrum, Large Diameter, Low Voltage IRLs ...................... 5-52

Table 5.4.5 CSL 1 for Modified Spectrum, Large Diameter, Low Voltage IRLs ..................... 5-52

Table 5.4.6 CSL 1 for Standard Spectrum, Small Diameter, Low Voltage IRLs ...................... 5-54

Table 5.4.7 CSL 1 for Standard Spectrum, Large Diameter, High Voltage IRLs ..................... 5-55

Table 5.4.8 Summary of Candidate Standard Levels for Covered IRLs ................................... 5-55
5-1 

CHAPTER 5. ENGINEERING ANALYSIS 

5.1 INTRODUCTION 

The U.S. Department of Energy (DOE) performed engineering analyses for both general 

service fluorescent lamps (GSFLs) and incandescent reflector lamps (IRLs). This chapter of the 

preliminary technical support document (TSD) provides the analyses DOE used to study 

representative lamps, to select candidate standard levels (CSLs), and to develop power rating 

estimates for the products analyzed. After selecting representative product classes, DOE then 

selects lamps that represent the baseline efficacy, as well as more efficacious substitutes for 

those baseline lamps. DOE uses these more efficacious lamps to develop CSLs. While DOE 

establishes CSLs based on lamp designs for the engineering analysis, for GSFLs it also develops 

lamp-and-ballast systems for use in the life-cycle cost (LCC) analysis and national impact 

analysis (NIA) because fluorescent lamps and ballasts operate together in practice. 

In energy conservation rulemakings for other products, DOE often develops costefficiency relationships in the engineering analysis. However, for this rulemaking, DOE derives 

CSLs in the engineering analysis and end-user prices in the product price determination. By 

combining the results of the engineering analysis and the product price determination, DOE 

derives typical inputs for use in the LCC and NIA. See chapter 7 of this TSD for discussion of 

DOE’s methodology for determining product prices. 

5.2 METHODOLOGY OVERVIEW

To the extent possible, DOE bases the engineering analysis on commercially available 

lamps that incorporate the design options identified in the technology assessment and screening 

analysis (chapters 3 and 4 of this TSD). The engineering analysis for each of the two categories 

of lamps DOE analyzes in this rulemaking (i.e., GSFLs and IRLs) follows a similar approach: 

1. Select representative product classes: DOE first reviews covered lamps and the associated 

product classes. When multiple product classes are needed, DOE selects certain classes as 

“representative” and concentrates its analytical effort on these classes. DOE selects 

representative product classes primarily because of their high market volumes. 

2. Select Baseline Lamps: For each representative product class, DOE selects a baseline lamp as 

a reference point against which to measure changes resulting from energy conservation 

standards. Typically, a baseline lamp is the most common, least efficacious lamp sold in a 

given product class. For this preliminary analysis, DOE uses performance data presented in 

manufacturer catalogs to determine lamp efficacy. DOE also considers other lamp 

characteristics in choosing the most appropriate baseline for each product class such as 

wattage, lumen output, and lifetime. For some of the representative product classes, DOE 

selects multiple baseline models to ensure consideration of different consumer economics. 

3. Identify More Efficacious Substitutes: DOE selects higher efficacy lamps as replacements for 

each of the baseline lamps. When selecting higher efficacy lamps, DOE considers only 

design options that meet the criteria outlined in the screening analysis (chapter 4 of this

TSD). For GSFLs, DOE pairs each lamp with an appropriate ballast because fluorescent 

lamps are a component of a system, and their performance is related to the ballast on which 
5-2 

they operate. DOE generally selects commercially available lamps as substitutes. For this 

rulemaking, however, DOE may also consider a model lamp developed for the 4-foot T5 

miniature bipin (MiniBP) high output (HO) product class (see section 5.3.3 and appendix 5A 

of this TSD for further detail). 

4. Determine Candidate Standard Levels. After identifying more efficacious substitutes for 

each baseline lamp, DOE develops CSLs. DOE bases its analysis on three factors: (1) the 

design options associated with the specific lamps studied; (2) the ability of lamps across 

wattages to comply with the CSL of a given product class;

a

and (3) the maximum 

technologically feasible efficacy level. DOE then scales the CSLs of representative product 

classes to those product classes not directly analyzed. 

The sections that follow discuss how DOE applies this methodology to each GSFL and 

IRL product class to create the engineering analysis. 

5.3 GENERAL SERVICE FLUORESCENT LAMPS 

5.3.1 Representative Product Classes 

As discussed in the market and technology assessment (chapter 3 of this preliminary 

TSD), DOE considered 12 product classes for GSFLs based on three class-setting factors: 

correlated color temperature (CCT), physical constraints, and lumen package. Of these product 

classes, DOE chose the following five classes as representative because of their high shipment 

volumes: 4-foot medium bipin (MBP), 8-foot single pin (SP) slimline, 8-foot recessed double 

contact (RDC) HO, 4-foot T5 MiniBP standard output (SO), and 4-foot T5 MiniBP HO – all 

with a CCT less than or equal to 4,500 kelvins (K). DOE directly analyzed these representative 

product classes. As indicated in shipment data, 4-foot MBP lamps constitute the vast majority of 

GSFL sales. These are followed, in decreasing order, by 4-foot MiniBP SO and HO lamps, 8-

foot SP slimline lamps, 8-foot RDC HO lamps, and 2-foot U-shaped lamps. Given the relatively 

small market share of 2-foot U-shaped lamps, DOE did not directly analyze these products. In 

addition, as lamps with CCTs greater than 4,500 K represent small market shares of total GSFL 

sales, DOE only directly analyzed lamps with CCTs less than or equal to 4,500 K. See chapter 3 

of this TSD for more information on lamp shipments. 

Table 5.3.1 lists the 12 product classes and identifies the representative product classes 

(indicated by gray shading) that DOE is considering in this preliminary analysis. 

 

a

 CSLs span multiple lamps of different wattages. In selecting CSLs, DOE considered whether these multiple lamps 

can meet the standard levels. 
5-3 

Table 5.3.1 Representative Product Classes for General Service Fluorescent Lamps 

Lamp Type CCT

4-foot medium bipin ≤ 4,500 K

> 4,500 K

2-foot U-shaped ≤ 4,500 K

> 4,500 K

8-foot single pin slimline ≤ 4,500 K

> 4,500 K

8-foot recessed double contact high output ≤ 4,500 K

> 4,500 K

4-foot T5 miniature bipin standard output ≤ 4,500 K

> 4,500 K

4-foot T5 miniature bipin high output ≤ 4,500 K

> 4,500 K

5.3.2 Baseline Lamps 

For each representative product class, DOE selects baseline lamps that are typically the 

most common, least efficacious lamps that meet existing standards. To identify baseline lamps, 

DOE reviews product offerings in catalogs, shipment information, and manufacturer feedback 

obtained during interviews. Common lamp types are selected based on characteristics such as 

diameter, wattage, CCT, and lifetime. DOE used rated efficacybto evaluate baseline lamps for 

this analysis. 

DOE published a final rule in July 2009 (hereafter the “2009 Lamps Rule”) that adopted 

standards for certain fluorescent lamps that required compliance in July 2012 (hereafter the “July 

2012 standards”). 74 FR 34080 (July 14, 2009). Although these standards are based on 

performance and do not restrict the sale of specific products, it is difficult for T12 lamps to 

comply with the July 2012 standards. For products classes that may include both T12 and T8 

products (the 4-foot MBP, 8-foot SP slimline, and 8-foot RDC HO product classes), DOE chose 

baseline lamps with T8 diameters. 

Based on DOE’s review of the market, a limited number of T12 lamps are currently 

available that comply with the July 2012 standards. DOE only considers non-exempt, standardscompliant lamps in the engineering analysis. Further, it will be difficult for T12 electronic 

ballasts to comply with the standards adopted by the 2011 Ballast Rule,c

thus further shifting the 

market away from T12 lamps. Additionally, historical shipments of most T12 lamps have been 

decreasing steadily and manufacturer feedback suggests that shipments will likely to continue to 

do so. For these reasons, DOE concluded that a T12 lamp is not representative of a commonly 

available lamp type and subsequently elected not to analyze a T12 baseline. 

 

b

 For GSFLs, the rated efficacy is the initial lumen output published in manufacturer catalogs divided by the 

American National Standards Institute (ANSI) rated wattage. For lamp types that do not have a defined ANSI rated 

wattage, DOE utilized the lamp’s nominal wattage to calculate rated efficacy. 

c

 The final rule amending energy conservation standards for fluorescent lamp ballasts published in 2011 with a 

compliance date of November 14, 2014. 76 FR 70548 (Nov. 14, 2011). The full text and all related documents of the 

2011Ballast Rule can be found on regulations.gov, docket number EERE-2007-BT-STD-0016 at 

www.regulations.gov/#!docketDetail;D=EERE-2007-BT-STD-0016. 
5-4 

A summary of the GSFL baseline lamps is shown in Table 5.3.2. 

Table 5.3.2 GSFL Baseline Lamps 

Representative 

Product Class

Baseline Lamps

Lamp 

Diameter

Nominal 

Wattage

ANSI 

Rated 

Wattage

Rated 

Efficacy**

Initial 

Lumen

Output†

Mean 

Lumen 

Output‡

Life

(IS)

Life

(PS) CRI

W W lm/W lm lm hr hr

4-foot MBP T8 32 32.5 89.2 2,900 2,725 24,000 40,000 83

8-foot SP 

slimline T8 59 60.1 98.2 5,900 5,430 24,000 - 82

8-foot RDC HO T8 86 84.0 95.2 8,000 7,600 18,000 - 78

4-foot T5 

MiniBP SO* T5 28 27.8 104.3 2,900 2,697 - 30,000 85

4-foot T5 

MiniBP HO* T5 54 53.8 92.9 5,000 4,850 - 24,000 86

* 4-foot T5 MiniBP SO and HO rated efficacy, initial lumen output, and mean lumen output given at 35 °C.

** Rated efficacy is catalog initial lumen output divided by the ANSI rated wattage.

† Initial lumen output is a lamp’s light output after 100 hours of seasoning.

‡ Mean lumen output is a measure of light output midway through the rated life of a lamp.

5.3.3 More Efficacious Substitutes 

After choosing a baseline lamp for each representative product class, DOE identifies 

more efficacious substitutes. Similar to the selection of baseline lamps, DOE used the rated 

efficacy to evaluate more efficacious replacement lamps in its analysis. DOE also sought to keep 

other characteristics of substitute lamps as similar as possible to the baseline lamps, such as rated 

life, color rendering index (CRI), and CCT. 

Higher efficacies are achieved through a variety of technologies. As discussed in the 

screening analysis (chapter 4 of this TSD), DOE considered commercially available GSFLs that 

use highly emissive electrode coatings, higher efficiency lamp fill gas composition, higher 

efficiency phosphors, glass coatings, or higher efficiency lamp diameter to achieve more 

efficacious lamp designs. These technologies are discussed in further detail in chapter 3 of this 

TSD. DOE utilized a database of commercially available lamps when identifying the more 

efficacious substitutes. However, for the 4-foot T5 MiniBP HO product class, DOE is analyzing 

a modeled lamp because, although there are no commercially available higher efficacy full 

wattage replacements, DOE believes that such a lamp could be manufactured with commercially 

available technologies (see section 5.3.6.5 and appendix 5A of this TSD for further details). 

5.3.4 Candidate Standard Levels

After identifying more efficacious substitutes for each of the baseline lamps, DOE 

develops CSLs based on the consideration of several factors, including: (1) the design options 

associated with the specific lamps being studied (e.g., grades of phosphor); (2) the ability of 

lamps across wattages to comply with the standard level of a given product class; and (3) the 

maximum technologically feasible (“max-tech”) level. Although fluorescent lamps are a 

component of a system that often includes ballasts and fixtures, DOE based its CSLs only on 

lamp performance because GSFLs are the subject of this rulemaking. DOE acknowledges, 

however, that the energy consumption of fluorescent lamps is related to the ballast on which they 
5-5 

operate. Therefore, DOE pairs each lamp with an appropriate ballast to better approximate realworld conditions. Lamp-and-ballast systems are discussed in more detail in section 5.3.5.

When selecting CSLs, DOE only considered CSLs at which a full wattage version of the 

lamp type was available because reduced wattage lamps have limited utility. Manufacturer 

feedback indicated that reduced wattage lamps have problems starting in cold temperature 

applications below 60-65 °F, and may also exhibit striations in this temperature range. In 

manufacturer interviews, it was noted that striations remain an issue for reduced wattage lamps 

because not all ballasts contain striation control circuitry, and those that are equipped with 

striation control circuitry do not completely eliminate striation. 

As described in the previous section, DOE used a database of commercially available 

lamps, when possible, and their associated rated efficacies (catalog initial lumen output divided 

by the ANSI rated wattage) to determine appropriate CSLs. However, DOE acknowledges that 

efficacies of lamps when reported for compliance purposes can vary from catalog rated values. 

Therefore, DOE also analyzed publicly available data submitted to DOE by manufacturers to 

demonstrate compliance with existing energy conservation standards.d Because the compliance 

requirements for GSFLs require the reported efficacy to be the lower of the average efficacy or 

the lower confidence limit divided by 0.97 and also impose specific sampling requirements, the 

efficacy reported for compliance may differ from the rated efficacy reported in catalogs. 

Therefore, DOE adjusted CSLs to account for compliance data when available. DOE notes that 

there is a limited amount of publicly available compliance information for lamps covered under 

this rulemaking. DOE found there to be compliance data for only 40 percent of covered GSFL 

products compliant (based on catalog efficacy) with the July 2012 standards. For more 

information on specific adjustments to the CSLs, see section 5.3.6. 

5.3.5 GSFL Systems 

Because fluorescent lamps operate on a ballast in practice, DOE analyzed lamp-andballast systems in the engineering analysis. DOE believes that pairing a lamp with a ballast more 

accurately captures real-world energy use and light output. 

DOE is aware that lumen package is an important consideration for consumers. If 

consumers do not have the option to purchase substitute lamp-and-ballast systems with similar 

lumen packages, a modification in the lighting design of their space (e.g., change in fixture 

spacing) may be required to maintain a similar light output. In assessing light output of the 

representative systems, DOE made a distinction between mean and initial lumen output. 

Consistent with industry consensus on efficacy measurements, DOE requires initial lumen output 

be used to determine lamp efficacy in its test procedures for GSFLs. Therefore, as stated in 

section 5.3.2, DOE used catalog initial lumen output to calculate efficacy when determining 

CSLs. However, the light output of a lamp decreases over time. To account for this real-world 

depreciation in lumens, DOE analyzed more efficacious systems that maintain mean lumen 

output within 10 percent of the baseline, when possible. Mean lumen output is a measure of light 

 

d

 The publicly available compliance information for GSFLs can be found in DOE’s Compliance Certification 

Database available here: www.regulations.doe.gov/certification-data/. 
5-6 

output midway through the rated life of a lamp, and a 10 percent change is a common parameter 

used by lighting designers to specify acceptable substitute products on the basis of light output. 

In the LCC analysis, DOE considers lamp purchase events, or events that cause a 

consumer to purchase a new lamp. For GSFLs, DOE determined that consumers may purchase a 

new lamp to operate on an existing ballast or purchase a new lamp as part of a new lamp-andballast system. Therefore, DOE considered two different scenarios in the engineering analysis. 

For both scenarios, DOE only selected replacement systems that do not have higher energy 

consumption than the baseline system. The NIA allows consumers to make other choices, 

including selecting an alternative lighting technology. See chapter 9 of this TSD for more detail. 

For the first event, known as the lamp replacement scenario, DOE selects reduced 

wattage replacement lamps that can operate on the installed ballast, as this is the only way to 

reduce energy consumption. These lower-wattage replacement lamps have a higher efficacy and 

produce similar light output as the baseline lamp. For the second event, known as the lamp-andballast replacement scenario, DOE selects lamps that have the same or lower wattage compared 

to the baseline lamp and also selects a new ballast with potentially different performance 

characteristics, such as ballast factor (BF) or ballast luminous efficiency (BLE). For example, a 

lamp-and-ballast system with a more efficacious, similar wattage lamp and lower BF ballast will 

consume less energy while maintaining similar light output compared to the baseline system. 

For both substitution scenarios, DOE determined energy consumption by calculating the 

system input power of the lamp-and-ballast system. The system input power represents the 

energy consumption rate of both the lamp and ballast, and therefore is greater than the rated 

power of the lamp alone. In addition to the rated lamp power, the system power is also affected 

by the number of lamps operated per ballast, type of ballast used (i.e., electronic or magnetic), 

starting method, and the BF of that ballast. 

The following sections discuss in more detail how DOE selected ballasts for each 

representative lamp-and-ballast pairing.

5.3.5.1 Ballast Selection 

DOE used manufacturer feedback and information provided in the 2011 Ballast Rule to 

determine which fluorescent lamp ballasts were representative of the market. DOE first 

identified the most common number of lamps operated per ballast, the most common starting 

methods by ballast type, and the most common mode of operation (i.e., electronic or magnetic). 

DOE then selected an appropriate ballast for each representative lamp-and-ballast pairing. 

Representative Ballast Types 

Fluorescent lamp ballasts can often operate different numbers of lamps; some ballast 

types can operate up to six individual lamps. In the 2011 Ballast Rule, DOE identified the 

number of lamps most commonly operated by fluorescent ballasts. In that rule, DOE estimated 
5-7 

that approximately 40 percent of ballasts that operate F32T8elamps (the most common 4-foot 

MBP lamp) are two-lamp ballasts, 30 percent are four-lamp ballasts, 20 percent are three-lamp 

ballasts, and 10 percent are one-lamp ballasts. Thus, DOE directly analyzed both two-lamp and 

four-lamp ballasts that operate 4-foot MBP lamps. For ballasts designed to operate 8-foot SP 

slimline, 8-foot RDC HO, 4-foot T5 MiniBP HO, and 4-foot T5 MiniBP SO lamps, DOE 

estimated that the majority are two-lamp ballasts and therefore concentrated its analytical effort 

on two-lamp ballasts for these lamp types. In this preliminary analysis, to most accurately 

represent the market, DOE chose to analyze ballasts that operate the same number of lamps as 

those analyzed in the 2011 Ballast Rule. Manufacturer feedback confirmed that these are the 

most common products. 

In addition to operating different numbers of lamps, fluorescent lamp ballasts can also 

have different starting methods. The 2011 Ballast Rule identified the most common starting 

methods for each ballast type. In the 2011 Ballast Rule, for ballasts that operate 4-foot MBP 

lamps, DOE directly analyzed the instant start (IS)/rapid start (RS)fproduct class and 

programmed start (PS) product class in the commercial and industrial sectors, and the IS/RS 

product class in the residential sector. DOE found that the majority of T8 ballasts were IS and 

therefore analyzed an IS T8 representative ballast type for 4-foot MBP lamps, 8-foot SP slimline 

lamps,gand 8-foot RDC HO lamps. DOE also directly analyzed PS ballasts for 4-foot MBP 

lamps due to their increasing market share. For ballasts that operate 4-foot T5 MiniBP SO lamps 

and 4-foot T5 MiniBP HO lamps, DOE directly analyzed PS ballasts, which represent the vast 

majority of ballasts for these lamp types. In this preliminary analysis, to accurately reflect the 

market, DOE selected ballasts with the same starting methods analyzed in the 2011 Ballast Rule. 

Manufacturer feedback confirmed that these starting method combinations are the most common 

for each lamp type. 

As noted in the 2011 Ballast Rule, it is difficult for magnetic ballasts to comply with the 

standard levels adopted by the previous final rule amending fluorescent lamp ballast energy 

conservation standards (65 FR 56740 [Sept. 19, 2000]) and the standards established by the 

Energy Policy Act of 2005 (Pub.L. 109-58). As a result, electronic ballasts make up the majority 

of ballasts available on the market. Standards adopted by the 2011 Ballast Rule, which require 

compliance in November 2014, will effectively eliminate any remaining magnetic ballasts on the 

market. Therefore, DOE analyzes only electronic ballasts in this preliminary analysis. 

Table 5.3.3 shows the representative lamp-and-ballast system pairings that DOE analyzed 

in this preliminary analysis. 

 

e

 Lamp types are identified by a series of letters and numbers. The letter “F” designates a fluorescent lamp. The twodigit number following identifies either the nominal lamp wattage for 4-foot lamps or the lamp length in inches for 

8-foot lamps. The two-digit number is then followed by the letter “T” for tubular and the lamp diameter in eights of 

an inch. 

f

Although IS and RS are different starting method technologies, DOE determined in the 2011 Ballast Rule that IS 

and RS ballasts were commonly used as substitutes for each other, and therefore separate product classes were not 

established. See chapter 3 of the TSD for the 2011 Ballast Rule for more information available on regulations.gov, 

docket number EERE-2007-BT-STD-0016 at www.regulations.gov/#!docketDetail;D=EERE-2007-BT-STD-0016.

g

 Instant start is the only starting method compatible with 8-foot slimline lamps. 
5-8 

Table 5.3.3 Representative Lamp-and-Ballast System Pairings 

Lamp Type Ballast Type

4-foot MBP

2-lamp IS, electronic

2-lamp PS, electronic

4-lamp IS, electronic

4-lamp PS, electronic

2-lamp IS for residential use, 

electronic

8-foot SP slimline 2-lamp IS, electronic

8-foot RDC HO 2-lamp IS, electronic

4-foot T5 MiniBP SO 2-lamp PS, electronic

4-foot T5 MiniBP HO 2-lamp PS, electronic

Ballast Models Used in Representative Lamp-And-Ballast Pairings 

After determining the representative lamp-and-ballast system pairings, DOE selected 

specific ballast models to use in each system analyzed. DOE utilized the commercially available 

ballast models analyzed and tested for the 2011 Ballast Ruleh

to pair with the representative lamp 

units. DOE believed this to be an accurate representation of ballasts currently available on the 

market, and the most complete source of ballast efficiency in terms of the BLE metric, which is 

defined as total lamp arc power divided by ballast input power. 

For the lamp replacement scenario, DOE selected a ballast that represents the product that 

is most likely to be installed in 2014. DOE utilized the representative units associated with the 

efficiency levels adopted in the 2011 Ballast Rule or ballasts with comparable performance 

characteristics so as to best represent the market in terms of efficiency. For example, because 

DOE adopted EL3 for ballasts that operate 4-foot MBP lamps, DOE used the ballast 

performance characteristics for the representative units at EL3 to pair with 4-foot MBP lamps in 

the lamp replacement scenario. 

As stated previously, DOE tried to select lamp-and-ballast systems that maintained mean 

lumen output within 10 percent of the baseline system, when possible. However, in some cases 

DOE was unable to pair reduced wattage lamps with ballasts that would provide a system mean 

lumen output within 10 percent of the baseline while still achieving energy savings. Reduced 

wattage lamps typically have lower lumen output compared to full wattage versions. In order to 

achieve system mean lumen output within 10 percent of a full wattage baseline, some reduced 

wattage lamps require the use of a high BF ballast. However this combination could increase the 

overall energy consumption of the system relative to the baseline. In such cases, priority was 

given to achieving energy savings over maintaining lumen output as only systems that do not 

increase energy consumption are considered in the engineering analysis. 

 

h

 The ballast test data from the 2011 Ballast Rule is publicly available on at 

www.regulations.gov/#!documentDetail;D=EERE-2007-BT-STD-0016-0054. 
5-9 

For the lamp-and-ballast replacement scenario, DOE selected ballast models using a 

different methodology. For this scenario, DOE selected a higher efficiency (based on BLE) 

ballast at the baseline than selected in the lamp replacement scenario because it was assumed that 

a newly purchased ballast would likely be more efficient than an installed ballast. For the 

representative units at higher CSLs, DOE selected a ballast with a lower BF than the normal BF 

baseline ballast, when possible, in order to further improve energy savings. Thus, at each CSL 

above the baseline, DOE identified a commercially available ballast that had the lowest BF 

possible while still maintaining a system mean lumen output within 10 percent of the baseline 

system. When multiple ballasts with the same BF existed, DOE selected the most efficient ballast 

based on BLE as this was considered to be the most likely substitute in a ballast replacement 

scenario designed to achieve energy savings. In some cases, DOE was unable to pair a reduced 

wattage representative unit with a ballast that would provide a system mean lumen output within 

10 percent of the baseline while still achieving energy savings. As stated previously, priority was 

given to energy savings over maintaining lumen output as only systems that do not increase 

energy consumption relative to the baseline are considered in the engineering analysis. 

5.3.5.2 System Input Power Calculation 

After selecting ballasts to pair with the representative units at each CSL, DOE then 

calculated the system input power. The system input power depends on both the total lamp arc 

power operated by the ballast and the ballast’s efficiency, or BLE. DOE first calculated the total 

lamp arc power of the system by multiplying the catalog BF, number of lamps operated by the 

ballast, and the high frequency reference lamp arc power. Because DOE only analyzed electronic 

ballasts in this rulemaking, all lamp-and-ballast systems were high frequency. The high 

frequency reference lamp arc powers are shown in Table 5.3.4. If a high frequency reference arc 

power was not available for a specific lamp type, DOE used the nominal wattage. 

Table 5.3.4 High Frequency Reference Lamp Arc Powers 

Lamp Type Nominal Wattage High Frequency Reference

Lamp Arc Power

T8 4-foot MBP

32 29.0

28 26.0

25 24.2

T8 8-foot SP slimline

59 60.1

54 N/A

50 N/A

T8 8-foot RDC HO 86 84.0

T5 MiniBP SO

28 27.8

26 N/A

25 N/A

T5 MiniBP HO

54 53.8

50 N/A

47 N/A

For ballasts paired with full wattage lamps, DOE was able to use the publicly available 

tested BLE value for the selected ballast model to determine the system input power. Using the 

calculated total lamp arc power and tested BLE value of the ballast model, DOE then calculated 

the system input power, equivalent to ballast input power, using Eq. 5.1. This process was 

repeated for each full wattage lamp-and-ballast system pairing. 
5-10

 

 

 

Where: 

β = 1.0 for high frequency ballasts 

Eq. 5.1 

Because the 2011 Ballast Rule did not test ballasts when operating reduced wattage 

lamps, DOE had to determine the expected BLE using the test results of the ballast operating full 

wattage lamps and the known power-efficiency relationship of ballasts. In the 2011 Ballast Rule, 

DOE developed a power law equation to model the trend between total lamp arc power and 

average BLE. The power law equation followed the form: 

 

 

 

Where: 

power = total lamp arc power 

Eq. 5.2 

Similar to the full wattage system, DOE first calculated the total lamp arc power of the 

reduced wattage lamp-and-ballast system. DOE assumed that BF does not change when 

operating reduced wattage lamps and therefore used the catalog BF of the ballast when operating 

full wattage lamps to calculate the total lamp arc power for both full wattage and reduced 

wattage systems. 

In general, as lamp arc power increases or decreases, BLE increases or decreases as well.i

In the 2011 Ballast Rule, DOE defined this relationship using the equation above. In this 

rulemaking, DOE assumed that this relationship holds true for individual ballasts. Therefore, 

DOE assumed that an individual ballast operating full wattage lamps would have the same 

coefficient B when operating reduced wattage lamps. Using this assumption, DOE calculated the 

selected ballast model’s coefficient B when operating full wattage lamps using the tested BLE 

value from the 2011 Ballast Rule, the calculated total lamp arc power at full wattage ̧ and the 

appropriate exponent C, which is dependent on the ballast starting method.jThe coefficient A 

was assumed to be one.k

 DOE was then able to calculate the new BLE when operating reduced 

wattage lamps by using the total lamp arc power when operating reduced wattage lamps and 

keeping the coefficient B, the exponent C, and the coefficient A the same. Given this expected 

 

i

 For more information on the power versus efficiency relationship of ballasts, please see TSD chapter 3 of the 2011 

Ballast Rule, available on regulations.gov, docket number EERE-2007-BT-STD-0016 at 

www.regulations.gov/#!docketDetail;D=EERE-2007-BT-STD-0016. 

j

 The exponent C was found to be 0.25 for IS/RS ballasts and 0.37 for PS ballasts in the 2011 Ballast Rule. See 

chapter 5 of the 2011 Ballast Rule TSD, available on regulations.gov, docket number EERE-2007-BT-STD-0016 at 

www.regulations.gov/#!docketDetail;D=EERE-2007-BT-STD-0016. 

k

 The coefficient A was used as an adjustment factor for testing variation when developing efficiency levels in the 

2011 Ballast Rule. In this rulemaking, A was assumed to be one as no adjustments were made to the ballast test data 

used in the calculation. 
5-11

BLE and total lamp arc power calculated in the previous steps, DOE determined the system input 

power of the reduced wattage lamp-and-ballast system using Eq. 5.1. This process was repeated 

for each unique reduced wattage lamp-and-ballast pairing. 

5.3.6 Engineering Results by Representative Product Classes 

The following sections discuss the lamp models DOE is considering for the five 

representative product classes considered in the engineering analysis. 

5.3.6.1 Four-Foot MBP GSFLs with CCTs ≤ 4,500 K 

Baseline Lamps

DOE selected baseline lamps as reference points from which to measure changes 

resulting from potential energy conservation standards. As discussed in section 5.2, a baseline 

lamp is typically the most common, least efficacious lamp sold in a given product class. To 

determine energy savings and changes in price, DOE compared representative lamps at each 

higher efficacy level with the baseline unit. 

DOE considered a number of criteria when selecting which commercially available lamp 

would serve as a baseline. The 4-foot MBP lamps have traditionally been manufactured in both 

T8 and T12 diameters. DOE selected a T8 4-foot MBP as a baseline based on its high shipment 

volume (see section 5.3.2 for an additional discussion of why DOE did not analyze a T12 

baseline). In 2011, T8 lamps represented 74 percent of the 4-foot MBP shipments, while 

shipments of T12 lamps represented 26 percent. 

Through a review of product offerings and manufacturer feedback, DOE determined that 

32 W is the most common wattage for T8 4-foot MBP lamps by a substantial margin. For the 32 

W T8 4-foot MBP baseline lamp, DOE identified typical performance characteristics. DOE 

selected a baseline lamp that uses an 800 series rare earth phosphor. These lamps typically have 

a CRI of 80 to 86. For all baseline lamps and more efficacious lamp designs, DOE analyzed 

fluorescent lamps with a CCT of 4,100 K because it represents the highest volume CCT for this 

category of lamps. As mentioned in section 5.3.5, DOE chose to pair representative lamps with 

both an IS ballast and a PS ballast. The typical lifetime for the baseline lamp is 24,000 hours 

when paired with an IS ballast and 40,000 hours when paired with a PS ballast. 

Although DOE is analyzing 4-foot MBP lamps in the residential sector, DOE did not 

identify a baseline lamp specific to the residential sector. After reviewing available catalog 

information, DOE found that the T8 4-foot MBP lamps sold in the residential sector share similar 

characteristics as those offered in the commercial and industrial sectors. Therefore, DOE did not 

analyze a separate baseline for the residential sector. 

Typically, a baseline product is a unit that just meets the existing energy conservation 

standard for the product (89 lm/W for this product class). DOE identified a lamp with an efficacy 

of 89.2 lm/W to be the most common, least efficacious 32 W T8 4-foot MBP lamp available that 

just meets existing standards. This lamp also represented the lowest efficacy of standards-
5-12

compliant lamps in this product class. Table 5.3.5 lists the characteristics of the 32 W T8 4-foot 

MBP baseline lamp. 

Table 5.3.5 Baseline Lamp for the 4-foot MBP Representative Product Class 

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp

Light 

Output

Rated 

Life 

(IS)

Rated

Life 

(PS) CRI

CCT

W W lm/W lm lm hr hr K

T8 32 32.5 89.2 2,900 2,725 24,000 40,000 83 4,100

Candidate Standard Levels and More Efficacious Substitutes

In general terms, DOE based its CSLs on the design options described below. Because 

utilizing higher efficiency phosphors is the most common method to achieve higher efficacies, 

DOE describes the phosphor technology associated with each CSL: 

CSL 1: This level requires the use of an improved 800 series full wattage (32 W) T8 lamp 

in which the phosphor mix and/or coating is enhanced to increase efficacy. 

CSL 2: This level represents max tech, the most efficacious products available today. The 

32 W T8 lamps use premium 800 series rare earth phosphor and are referred to as high lumen 

products. Reduced wattage 25 W T8 and 28 W T8 lamps that produce similar lumen outputs as 

the baseline unit also meet this CSL.

Figure 5.3.1 illustrates the two initial CSLs on a plot with the representative lamps. A line 

at 89 lm/W denotes the existing energy conservation standard (the July 2012 standards). The 

square box identifies the baseline lamp. The plot also shows the more efficacious substitutes that 

DOE considered as replacements. Some of the representative units shown on the plot are at the 

same wattage as the baseline, but have a higher efficacy; others have a combination of lower 

wattage and higher efficacy. 
5-13

Figure 5.3.1 Candidate Standard Levels for 4-foot MBP GSFLs with CCTs ≤ 4,500 K 

Table 5.3.6 provides detailed information on the 4-foot MBP representative lamps used in 

the engineering analysis and subsequent analyses. 

Table 5.3.6 4-foot MBP Representative Lamps 

CSL Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated 

Life (IS)

Rated 

Life (PS)

CRI

W W lm/W lm lm hr hr

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 40,000 83

1 T8 32 32.5 90.0 2,925 2,770 21,000 30,000 85

2 T8 25 26.6 93.0 2,475 2,350 24,000 40,000 85

2 T8 32 32.5 95.4 3,100 2,941 24,000 40,000 85

2 T8 28 28.4 96.0 2,725 2,560 24,000 40,000 85

As discussed above, DOE used commercially available lamps, when possible, and their 

associated rated efficacies (catalog initial lumen output divided by the ANSI rated wattage) to 

determine each initial CSL. However, to establish the minimum efficacy requirements for each 

CSL, DOE also considered data submitted to DOE by manufacturers to show demonstrate 

compliance with existing energy conservation standards. DOE determined if any adjustments 

were necessary to the initial CSLs to account for compliance efficacies of representative units 

CSL2

CSL1

Existing Standard

88.0

89.0

90.0

91.0

92.0

93.0

94.0

95.0

96.0

97.0

98.0

24 26 28 30 32 34 36

Catalog Rated Efficacy (lm/W)

ANSI Rated Wattage (W)
5-14

and/or equivalent lamps. DOE considered equivalent lamps to be manufacturer-identified cross 

references of the representative units or lamps deemed to have equivalent characteristics. 

By examining publicly available compliance reports, DOE found that approximately 47 

percent of available 4-foot MBP lamps had compliance information. Using this information, 

DOE determined that the representative unit and/or equivalent lamps complied with CSL 1. DOE 

also confirmed that CSL 2 was attainable for full wattage high lumen lamps, 25 W reduced 

wattage lamps, and 28 W reduced wattage lamps. Therefore, DOE concluded, based on 

compliance information, that no adjustments were necessary to the initial CSLs being considered 

for this product class. Figure 5.3.2 summarizes all available compliance information by lamp 

design (i.e., improved 800 series, high lumen, reduced wattage, and otherl

) and the resulting 

CSLs. 

Figure 5.3.2 All Compliance Report Data for 4-foot MBP GSFLs with CCTs ≤ 4,500 K 

Table 5.3.7 summarizes the final efficacy requirements at CSL 1 and CSL 2. 

 

l

 Lamps labeled as “other” designate lamp designs that are not representative of the most common characteristics 

identified. 

82.0

87.0

92.0

97.0

102.0

107.0

24 26 28 30 32 34 36

Compliance Efficacy (lm/W)

ANSI Rated Wattage (W)

Other

Improved 800 Series

High lumen

Reduced Wattage

CSL2

CSL1
5-15

Table 5.3.7 CSL 1 and CSL 2 for 4-foot MBP GSFLs with CCTs ≤ 4,500 K 

Candidate Standard Level Efficacy Requirement

lm/W

CSL 1 90.0

CSL 2 93.0
5-16

Engineering Summary

The first set of engineering results present the lamp replacement scenarios for the 4-foot MBP representative product class. In 

this scenario, energy savings are achieved through the use of higher efficacy, reduced wattage lamps. As stated in section 5.3.4, 

replacement lamp options were selected so that the system mean lumen output was within 10 percent of the baseline, when possible. 

When a ballast could not be selected that maintained system mean lumen output within 10 percent of the baseline system while still 

achieving energy savings, such as the 25 W 4-foot MBP lamp, priority was given to energy savings. 

Table 5.3.8 presents the engineering analysis results for two-lamp 4-foot MBP IS systems operating in the commercial and 

industrial sectors. Table 5.3.9 presents the engineering analysis results for two-lamp 4-foot MBP PS systems operating in the 

commercial and industrial sectors. Table 5.3.10 presents the engineering analysis results for four-lamp 4-foot MBP IS systems 

operating in the commercial and industrial sectors. Table 5.3.11 presents the engineering analysis results for four-lamp 4-foot MBP PS 

systems operating in the commercial and industrial sectors. Table 5.3.12 presents the engineering analysis results for two-lamp 4-foot 

MBP IS systems operating in the residential sector. 

Table 5.3.8 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 32 W T8, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated 

Life

Number 

of 

Lamps

Starting 

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 2 IS 0.88 56.0 91.2 5,104 4,796

CSL 2 T8 25 26.6 93.0 2,475 2,350 24,000 2 IS 0.88 46.9 90.8 4,356 4,136

CSL 2 T8 28 28.4 96.0 2,725 2,560 24,000 2 IS 0.88 50.3 90.9 4,796 4,506
5-17

Table 5.3.9 Lamp Replacement Engineering Analysis for a Two-Lamp Programmed Start 32 W T8, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated 

Life

Number 

of 

Lamps

Starting 

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 40,000 2 PS 0.88 56.0 91.2 5,104 4,796

CSL 2 T8 25 26.6 93.0 2,475 2,350 40,000 2 PS 0.88 47.0 90.6 4,356 4,136

CSL 2 T8 28 28.4 96.0 2,725 2,560 40,000 2 PS 0.88 50.4 90.8 4,796 4,506

Table 5.3.10 Lamp Replacement Engineering Analysis for a Four-Lamp Instant Start 32 W T8, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 4 IS 0.87 108.0 93.4 10,092 9,483

CSL 2 T8 25 26.6 93.0 2,475 2,350 24,000 4 IS 0.87 90.4 93.1 8,613 8,178

CSL 2 T8 28 28.4 96.0 2,725 2,560 24,000 4 IS 0.87 97.1 93.2 9,483 8,909

Table 5.3.11 Lamp Replacement Engineering Analysis for a Four-Lamp Programmed Start 32 W T8, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting 

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 40,000 4 PS 0.89 111.0 93.0 10,324 9,701

CSL 2 T8 25 26.6 93.0 2,475 2,350 40,000 4 PS 0.89 93.2 92.5 8,811 8,366

CSL 2 T8 28 28.4 96.0 2,725 2,560 40,000 4 PS 0.89 99.9 92.6 9,701 9,114
5-18

Table 5.3.12 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 32 W T8, 4,100 K System in the 

Residential Sector 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 2 IS 0.87 56.5 89.3 5,046 4,742

CSL 2 T8 25 26.6 93.0 2,475 2,350 24,000 2 IS 0.87 47.4 88.8 4,307 4,089

CSL 2 T8 28 28.4 96.0 2,725 2,560 24,000 2 IS 0.87 50.9 88.9 4,742 4,454

The next set of engineering results present the lamp-and-ballast replacement scenarios for the 4-foot MBP representative 

product class. For this scenario, as stated in section 5.3.5, the ballast with the lowest possible BF was selected that still maintained 

system mean lumen output within 10 percent of the baseline system. When a ballast could not be selected that maintained system 

mean lumen output within 10 percent of the baseline system while still achieving energy savings, such as the 25 W 4-foot MBP lamp, 

priority was given to energy savings. 

Table 5.3.13 presents the engineering analysis results for the replacement lamp-and-ballast combinations for two-lamp 4-foot 

MBP IS systems in the commercial and industrial sectors. Table 5.3.14 presents the engineering analysis results for the replacement 

lamp-and-ballast combinations for two-lamp 4-foot MBP PS systems in the commercial and industrial sectors. Table 5.3.15 presents 

the engineering analysis results for the replacement lamp-and-ballast combinations for four-lamp 4-foot MBP IS systems in the 

commercial and industrial sectors. Table 5.3.16 presents the engineering analysis results for the replacement lamp-and-ballast 

combinations for four-lamp 4-foot MBP PS systems in the commercial and industrial sectors. Table 5.3.17 presents the engineering 

analysis results for the replacement lamp-and-ballast combinations for two-lamp 4-foot MBP IS systems in the residential sector. 
5-19

Table 5.3.13 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 32 W T8, 4,100 K System in 

the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 2 IS 0.88 55.2 92.4 5,104 4,796

CSL 1 T8 32 32.5 90.0 2,925 2,770 21,000 2 IS 0.78 49.4 91.6 4,563 4,321

CSL 2 T8 25 26.6 93.0 2,475 2,350 24,000 2 IS 0.88 46.3 92.0 4,356 4,136

CSL 2 T8 32 32.5 95.4 3,100 2,941 24,000 2 IS 0.77 48.3 92.4 4,774 4,529

CSL 2 T8 28 28.4 96.0 2,725 2,560 24,000 2 IS 0.87 48.8 92.7 4,742 4,454

Table 5.3.14 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Programmed Start 32 W T8, 4,100 K 

System in the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 40,000 2 PS 0.88 56.0 91.2 5,104 4,796

CSL 1 T8 32 32.5 90.0 2,925 2,770 30,000 2 PS 0.88 56.0 91.2 5,148 4,875

CSL 2 T8 25 26.6 93.0 2,475 2,350 40,000 2 PS 0.88 47.0 90.6 4,356 4,136

CSL 2 T8 32 32.5 95.4 3,100 2,941 40,000 2 PS 0.88 56.0 91.2 5,456 5,176

CSL 2 T8 28 28.4 96.0 2,725 2,560 40,000 2 PS 0.88 50.4 90.8 4,796 4,506
5-20

Table 5.3.15 Lamp-and-Ballast Replacement Engineering Analysis for a Four-Lamp Instant Start 32 W T8, 4,100 K System in 

the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 4 IS 0.87 107.1 94.2 10,092 9,483

CSL 1 T8 32 32.5 90.0 2,925 2,770 21,000 4 IS 0.78 96.8 93.4 9,126 8,642

CSL 2 T8 25 26.6 93.0 2,475 2,350 24,000 4 IS 0.87 89.7 93.9 8,613 8,178

CSL 2 T8 32 32.5 95.4 3,100 2,941 24,000 4 IS 0.77 96.0 93.0 9,548 9,058

CSL 2 T8 28 28.4 96.0 2,725 2,560 24,000 4 IS 0.87 96.2 94.0 9,483 8,909

Table 5.3.16 Lamp-and-Ballast Replacement Engineering Analysis for a Four-Lamp Programmed Start 32 W T8, 4,100 K 

System in the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 40,000 4 PS 0.89 111.0 93.0 10,324 9,701

CSL 1 T8 32 32.5 90.0 2,925 2,770 30,000 4 PS 0.88 110.7 92.3 10,296 9,750

CSL 2 T8 25 26.6 93.0 2,475 2,350 40,000 4 PS 0.89 93.2 92.5 8,811 8,366

CSL 2 T8 32 32.5 95.4 3,100 2,941 40,000 4 PS 0.88 110.7 92.3 10,912 10,352

CSL 2 T8 28 28.4 96.0 2,725 2,560 40,000 4 PS 0.88 98.5 92.9 9,592 9,011
5-21

Table 5.3.17 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 32 W T8, 4,100 K System in 

the Residential Sector 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 32 32.5 89.2 2,900 2,725 24,000 2 IS 0.87 56.5 89.3 5,046 4,742

CSL 1 T8 32 32.5 90.0 2,925 2,770 21,000 2 IS 0.83 53.7 89.7 4,856 4,598

CSL 2 T8 25 26.6 93.0 2,475 2,350 24,000 2 IS 0.87 47.4 88.8 4,307 4,089

CSL 2 T8 32 32.5 95.4 3,100 2,941 24,000 2 IS 0.83 53.7 89.7 5,146 4,882

CSL 2 T8 28 28.4 96.0 2,725 2,560 24,000 2 IS 0.87 50.9 88.9 4,742 4,454
5-22

5.3.6.2 Eight-Foot SP Slimline GSFLs with CCTs ≤ 4,500 K 

Baseline Lamps

DOE selected baseline lamps as reference points from which to measure changes 

resulting from potential energy conservation standards. As discussed in section 5.2, a baseline 

lamp is typically the most common, least efficacious lamp sold in a given product class. To 

determine energy savings and changes in price, DOE compared representative lamps at each 

higher efficacy level with the baseline unit. 

DOE considered a number of criteria when selecting which commercially available lamp 

would serve as a baseline. The 8-foot SP slimline lamps have traditionally been manufactured in 

both T8 and T12 diameters. DOE selected a T8 8-foot SP slimline lamp as a baseline based on 

manufacturer feedback and recent shipment trends (see section 5.3.2 for an additional discussion 

of why DOE did not analyze a T12 baseline). 

Through a review of product offerings and manufacturer feedback, DOE determined that 

59 W is the most common wattage for T8 8-foot SP slimline lamps. For the 59 W T8 8-foot SP 

slimline lamp, DOE identified typical performance characteristics. The most common lamp at 

this wattage uses an 800 series rare earth phosphor. DOE selected a CCT of 4,100 K because it is 

the most common CCT for this lamp type. The typical lifetime of the baseline lamp was 24,000 

hours when paired with an IS ballast. This lamp type cannot operate on PS ballasts. 

Typically, a baseline product is a unit that just meets the existing energy conservation 

standard for the product (97 lm/W for this product class). DOE selected the lamp with the most 

common efficacy as the baseline (98.2 lm/W). Table 5.3.18 lists the characteristics of the 59 W 

8-foot SP slimline baseline lamp. 

Table 5.3.18 Baseline Lamp for the 8-foot SP Slimline Representative Product Class 

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial

Lamp

Light 

Output

Mean 

Lamp 

Light 

Output

Rated 

Life CRI

CCT

W W lm/W lm lm hr K

T8 59 60.1 98.2 5,900 5,430 24,000 82 4,100

Candidate Standard Levels and More Efficacious Substitutes

In general terms, DOE based CSL 1 on the design options described below. Because 

utilizing higher efficiency phosphors is the most common method to achieve higher efficacies, 

DOE describes the phosphor technology associated with the CSL: 

CSL 1: This level requires the use of improved 800 series full wattage (59 W) T8 lamps 

in which the phosphor mix and/or coating is enhanced to increase efficacy. Reduced wattage 

lamps, including the 54 W T8 and 50 W T8, that produce similar lumen output as the baseline 
5-23

unit also meet this CSL. This level represents max tech, the most efficacious products available 

today.

Figure 5.3.3 illustrates the initial CSL on a plot with the representative lamps. A line at 

97 lm/W denotes the existing energy conservation standard (the July 2012 standards). The square 

box identifies the baseline lamp. The plot also shows the more efficacious substitutes DOE 

considered as replacements. Some of the representative units shown on the plot are at the same 

wattage as the baseline, but have a higher efficacy; others have a combination of lower wattage 

and higher efficacy. 

Figure 5.3.3 Candidate Standard Level for 8-foot SP Slimline GSFLs with CCTs ≤ 4,500 K 

Table 5.3.19 provides detailed information on the 8-foot SP slimline representative lamps 

used in the engineering analysis and subsequent analyses. 

CSL1

Existing Standard

90.0

92.0

94.0

96.0

98.0

100.0

102.0

104.0

106.0

108.0

110.0

45 50 55 60 65

Catalog Rated Efficacy (lm/W)

ANSI Rated Wattage (W)
5-24

Table 5.3.19 8-foot SP Slimline Representative Lamps 

CSL Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp

Light 

Output

Mean 

Lamp 

Light 

Output

Rated Life

CRI

W W lm/W lm lm hr

Baseline T8 59 60.1 98.2 5,900 5,430 24,000 82

1 T8 59 60.1 99.0 5,950 5,650 24,000 85

1 T8 54 54 105.6 5,700 5,360 24,000 85

1 T8 50 50 108.0 5,400 5,075 24,000 85

As discussed above, DOE used commercially available lamps when possible and their 

associated rated efficacies (catalog initial lumen output divided by the ANSI rated wattage) to 

determine each initial CSL. However, to establish the minimum efficacy requirements for each 

CSL, DOE also considered data submitted to DOE by manufacturers to demonstrate compliance 

with existing energy conservation standards. DOE determined if any adjustments were necessary 

to the initial CSL to account for compliance efficacies of representative units and/or equivalent 

lamps. DOE considered equivalent lamps to be manufacturer-identified cross references of the 

representative units or lamps deemed to have equivalent characteristics. 

By examining publicly available compliance reports, DOE found that approximately 24 

percent of available 8-foot SP slimline lamps had compliance information. Using this 

information, DOE determined that the 54 W representative unit and/or equivalent lamps 

complied with CSL 1. Thus, based on publicly available compliance information, DOE 

concluded that no adjustment was necessary to the initial CSL being considered for this product 

class. Figure 5.3.4 summarizes all available compliance information by lamp design (i.e., 800 

series, reduced wattage, and otherm) and the resulting CSL. 

 

m

 Lamps labeled as “other” designate lamp designs that are not representative of the most common characteristics 

identified. 
5-25

Figure 5.3.4 All Compliance Report Data for 8-foot SP Slimline GSFLs with CCTs ≤ 4,500 

K

Table 5.3.20 summarizes the final efficacy requirement at CSL 1. 

Table 5.3.20 CSL 1 for 8-foot SP Slimline GSFLs with CCTs ≤ 4,500 K 

Candidate Standard Level Efficacy Requirement

lm/W

CSL 1 99.0

90.0

92.0

94.0

96.0

98.0

100.0

102.0

104.0

106.0

108.0

110.0

47 49 51 53 55 57 59 61

Compliance Efficacy (lm/W)

ANSI Rated Wattage

Other

800 Series

Reduced Wattage

CSL1
5-26

Engineering Summary

The first set of results present the lamp replacement scenarios for the 8-foot SP slimline representative product class. In this 

scenario, energy savings are achieved through the use of higher efficacy, reduced wattage lamps. As stated in section 5.3.4, 

replacement lamp options were selected so that the system mean lumen output was within 10 percent of the baseline, when possible. 

Table 5.3.21 presents the engineering analysis results for two-lamp 8-foot SP slimline IS systems operating in the commercial and 

industrial sectors. 

Table 5.3.21 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 59 W T8, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 59 60.1 98.2 5,900 5,430 24,000 2 IS 0.87 106.8 92.9 10,266 9,448

CSL 1 T8 54 54 105.6 5,700 5,360 24,000 2 IS 0.87 101.3 92.7 9,918 9,326

CSL 1 T8 50 50 108.0 5,400 5,075 24,000 2 IS 0.87 94.0 92.6 9,396 8,831

The next set of engineering results present the lamp-and-ballast replacement scenario for the 8-foot SP slimline representative 

product class. For this scenario, as stated in section 5.3.5, the ballast with the lowest possible BF was selected that still maintained 

system mean lumen output within 10 percent of the baseline system. Table 5.3.22 presents the engineering analysis results for the 

replacement lamp-and-ballast combinations for two-lamp 8-foot SP slimline IS systems in the commercial and industrial sectors. 
5-27

Table 5.3.22 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 59 W T8, 4,100 K System in 

the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 59 60.1 98.2 5,900 5,430 24,000 2 IS 0.87 106.8 92.9 10,266 9,448

CSL 1 T8 59 60.1 99.0 5,950 5,650 24,000 2 IS 0.85 104.0 93.2 10,115 9,605

CSL 1 T8 54 54 105.6 5,700 5,360 24,000 2 IS 0.85 98.7 93.0 9,690 9,112

CSL 1 T8 50 50 108.0 5,400 5,075 24,000 2 IS 0.85 91.5 92.9 9,180 8,628
5-28

5.3.6.3 Eight-Foot RDC HO GSFLs with CCTs ≤ 4,500 K 

Baseline Lamps

DOE selected baseline lamps as reference points from which to measure changes 

resulting from potential energy conservation standards. As discussed in section 5.2, a baseline 

lamp is typically the most common, least efficacious lamp sold in a given product class. To 

determine energy savings and changes in price, DOE compared representative lamps at each 

higher efficacy level with the baseline unit. 

DOE considered a number of criteria when selecting which commercially available lamp 

would serve as a baseline. The 8-foot RDC HO lamps have traditionally been manufactured in 

both T8 and T12 diameters. DOE selected a T8 8-foot RDC HO lamp as a baseline (see section 

5.3.2 for a discussion of why DOE did not analyze a T12 baseline). 

The most popular wattage associated with the 8-foot T8 RDC HO lamp type is 86 W. For 

the 86 W T8 lamp, DOE identified typical performance characteristics. The most common lamp 

uses a 700 series rare earth phosphor. DOE selected a CCT of 4,100 K because it is the most 

common CCT for this lamp type. The rated lifetime for these lamps is 18,000 hours when paired 

with an IS ballast. 

Typically, a baseline product is a unit that just meets the existing energy conservation 

standard for the product (92 lm/W for this product class). DOE identified a lamp with an efficacy 

of 95.2 lm/W to be the most common, least efficacious 86 W 8-foot T8 RDC HO lamp available 

that just meets existing standards. This lamp also represented the lowest efficacy of standardscompliant lamps in this product class. Table 5.3.23 lists the characteristics of the 86 W T8 8-foot 

RDC HO baseline lamp. 

Table 5.3.23 Baseline Lamp for the 8-foot RDC HO Representative Product Class 

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated 

Life CRI

CCT

W W lm/W lm lm hr K

T8 86 84.0 95.2 8,000 7,600 18,000 78 4,100

Candidate Standard Levels and More Efficacious Substitutes

In general terms, DOE based CSL 1 on the design options described below. Because 

utilizing higher efficiency phosphors is the most common method to achieve higher efficacies, 

DOE describes the phosphor technology associated with the CSL: 

CSL 1: This level requires the use of an 800 series rare earth phosphor and represents 

max tech, the most efficacious products available today.
5-29

Figure 5.3.5 illustrates the initial CSL on a plot with the representative lamps. A line at 

92 lm/W denotes the existing energy conservation standard (the July 2012 standards). The square 

box identifies the baseline lamp. The plot also shows more efficacious substitutes DOE 

considered as replacement lamps. In this product class, all of the representative units shown on 

the plot are at the same wattage, but have a higher efficacy. 

Figure 5.3.5 Candidate Standard Level for 8-foot RDC HO GSFLs with CCTs ≤ 4,500 K 

Table 5.3.24 provides detailed information on the 8-foot RDC HO representative lamps 

used in the engineering analysis and subsequent analyses. 

Table 5.3.24 8-foot RDC HO Representative Lamps 

CSL Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated Life

CRI

W W lm/W lm lm hr

Baseline T8 86 84.0 95.2 8,000 7,600 18,000 78

1 T8 86 84.0 97.6 8,200 7,800 18,000 86

As discussed above, DOE used commercially available lamps when possible and their 

associated rated efficacies (catalog initial lumen output divided by the ANSI rated wattage) to 

determine each initial CSL. However, to establish the minimum efficacy requirements for each 

CSL, DOE also considered data submitted to DOE by manufacturers to demonstrate compliance 

with existing energy conservation standards. DOE determined if any adjustments were necessary 

CSL1

Existing Standard

90.0

91.0

92.0

93.0

94.0

95.0

96.0

97.0

98.0

99.0

100.0

80 82 84 86 88 90

Catalog Rated Efficacy (lm/W)

ANSI Rated Wattage (W)
5-30

to the initial CSL to account for compliance efficacies of representative units and/or equivalent 

lamps. DOE considered equivalent lamps to be manufacturer-identified cross references of the 

representative units or lamps deemed to have equivalent characteristics. 

By examining publicly available compliance reports, DOE found that approximately 38 

percent of available 8-foot RDC HO lamps analyzed had compliance information. Based on this 

information, DOE found that an adjustment to CSL 1 was necessary. DOE adjusted CSL 1 to the 

lowest reported compliance efficacy of 97.0 lm/W for 800 series full wattage T8 lamps. Figure 

5.3.6 summarizes all available compliance information by lamp design (i.e., 700 series and 800 

series) and resulting CSL. 

Figure 5.3.6 All Compliance Report Data for 8-foot RDC HO GSFLs with CCTs ≤ 4,500 K 

Table 5.3.25 summarizes the final efficacy requirement at CSL 1. 

Table 5.3.25 CSL 1 for 8-foot RDC HO GSFLs with CCTs ≤ 4,500 K 

Candidate Standard Level Efficacy Requirement

lm/W

CSL 1 97.0

90.0

91.0

92.0

93.0

94.0

95.0

96.0

97.0

98.0

99.0

100.0

80 82 84 86 88 90

Compliance Efficacy (lm/W)

ANSI Rated Wattage (W)

700 Series

800 Series

CSL1

Adjusted CSL1
5-31

Engineering Summary

The first set of results present the lamp replacement scenario for the 8-foot RDC HO representative product class. In this 

scenario, energy savings are achieved through the use of higher efficacy, reduced wattage lamps. However, for this product class, 

DOE identified no commercially available reduced wattage 8-foot RDC HO lamps. Therefore, the lamp replacement scenario analyzes 

a more efficient full wattage 8-foot RDC HO lamp as a replacement. Table 5.3.26 presents the engineering analysis results for twolamp 8-foot RDC HO systems operating in the commercial and industrial sectors. 

Table 5.3.26 Lamp Replacement Engineering Analysis for a Two-Lamp Instant Start 86 W T8, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life Number 

of Lamps

Starting 

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 86 84 95.2 8,000 7,600 18,000 2 IS 0.81 148.4 91.7 12,960 12,312

CSL 1 T8 86 84 97.6 8,200 7,800 18,000 2 IS 0.81 148.4 91.7 13,284 12,636

The next set of engineering results present the lamp-and-ballast replacement scenario for the 8-foot RDC HO representative 

product class. For this scenario, as stated in section 5.3.5, the ballast with the lowest possible BF was selected that still maintained 

system mean lumen output within 10 percent of the baseline system. For this product class, no low BF ballast was identified, thus the 

same ballast was utilized at the higher efficacy level. Table 5.3.27 presents the engineering analysis results for the replacement lampand-ballast combination for two-lamp 8-foot RDC HO IS systems in the commercial and industrial sectors. 
5-32

Table 5.3.27 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Instant Start 86 W T8, 4,100 K System in 

the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life Number 

of Lamps

Starting 

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T8 86 84 95.2 8,000 7,600 18,000 2 IS 0.81 148.4 91.7 12,960 12,312

CSL 1 T8 86 84 97.6 8,200 7,800 18,000 2 IS 0.81 148.4 91.7 13,284 12,636
5-33

5.3.6.4 Four-Foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 K 

Baseline Lamps

DOE selected baseline lamps as reference points from which to measure changes 

resulting from potential energy conservation standards. As discussed in section 5.2, a baseline 

lamp is typically the most common, least efficacious lamp sold in a given product class. To 

determine energy savings and changes in price, DOE compared representative lamps at each 

higher efficacy level with the baseline unit. 

DOE considered a number of criteria when selecting which commercially available lamp 

would serve as a baseline. The most popular wattage associated with the 4-foot T5 MiniBP SO 

product class is 28 W. Therefore, DOE selected a 28 W 4-foot T5 MiniBP SO lamp as a 

baseline. For the 28 W 4-foot T5 MiniBP SO baseline lamp, DOE identified typical performance 

characteristics. The lamps that fall within this product class exclusively utilize 800 series rare 

earth phosphors. As with the baseline fluorescent lamps in other covered product classes, DOE 

selected a CCT of 4,100 K because it is the most common CCT for this lamp type. The typical 

operating lifetime for these lamps is 30,000 hours when paired with a PS ballast. 

Typically, a baseline product is a unit that just meets the existing energy conservation 

standard for the product (86 lm/W for this product class). DOE identified a lamp with an efficacy 

of 104.3 lm/W at 35 °C (93.5 lm/W at 25 °C, the temperature at which lamps are tested for 

compliance) as the most common, least efficacious 28 W 4-foot T5 MiniBP SO lamp. Table 

5.3.28 lists the characteristics of the 28 W 4-foot T5 MiniBP SO baseline lamp. 

Table 5.3.28 Baseline Lamp for the 4-foot T5 MiniBP Standard Output Representative 

Product Class 

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output (at 

35 °C)

Mean 

Lamp 

Light 

Output (at 

35 °C)

Rated Life 

CRI

CCT

W W lm/W lm lm hr K

T5 28 27.8 104.3 2,900 2,697 30,000 85 4,100

Candidate Standard Levels and More Efficacious Substitutes

The following discussion identifies the steps and technologies associated with the CSL 

DOE considered for the 4-foot T5 MiniBP SO representative product class. DOE is aware that 

many T5 SO lamps are operated at 35 °C and all manufacturers report performance at 35 °C in 

their catalogs. Therefore, DOE selected more efficacious replacements and developed initial 

CSLs for T5 SO lamps based on 35 °C catalog data. However, the DOE test procedure for T5 

lamps requires the lamps to be tested at 25 °C. Because the test procedure is used to determine 

compliance with DOE energy conservation standards, DOE adjusted the CSLs to account for the 

efficacy at 25 °C. Specifically, when operated at 25 °C, the lumen output of T5 lamps is 

approximately 10 percent lower than the lumen output of such lamps when operated at 35 °C. 
5-34

DOE also utilized certain manufacturers’ catalog information if performance characteristics were 

provided for lamp operation at 25 °C. 

In general terms, DOE based CSL 1 on the design options described below. Because 

utilizing higher efficiency phosphors is the most common method to achieve higher efficacies, 

DOE describes the phosphor technology associated with the CSL: 

CSL 1: This level represents higher efficacy improved 800 series phosphor 4-foot T5 

MiniBP SO lamps in which the phosphor mix and/or coating is enhanced. Full wattage 28 W 

lamps (with a rated efficacy of 109.7 lm/W at 35 °C operation) meet this level. For reduced 

wattage lamps, a reduced wattage 26 W 4-foot T5 MiniBP SO lamp (with a rated efficacy of 

111.5 lm/W at 35 °C operation) and a reduced wattage 25 W lamp (with a rated efficacy of 116.0 

lm/W at 35 °C operation) also meet this level. This level represents max tech, the most 

efficacious products available today.

DOE developed an initial CSL based on catalog values of more efficacious lamps that 

DOE selected to analyze as representative units. The existing energy conservation standard (the 

July 2012 standards) is 86 lm/W (at 25 °C). Figure 5.3.7 illustrates the initial CSL for this 

rulemaking on a plot of the efficacies of the representative lamps at 35 °C. The square box 

identifies the baseline lamp. The plot also shows the more efficacious substitutes DOE 

considered as replacement lamps. Some of the representative units shown on the plot are at the 

same wattage as the baseline, but have a higher efficacy; others have a combination of lower 

wattage and higher efficacy. 
5-35

Figure 5.3.7 Candidate Standard Level for 4-foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 

K, at 35 °C 

Table 5.3.29 provides detailed information on the 4-foot T5 MiniBP SO representative 

lamps used in the engineering analysis and subsequent analyses. 

Table 5.3.29 4-foot T5 MiniBP SO Representative Lamps 

CSL Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output (at 

35 °C)

Mean 

Lamp 

Light 

Output (at 

35 °C)

Rated Life

CRI

W W lm/W lm lm hr

Baseline T5 28 27.8 104.3 2,900 2,697 30,000 85

1 T5 28 27.8 109.7 3,050 2,898 30,000 85

1 T5 26 26 111.5 2,900 2,660 25,000 85

1 T5 25 25 116.0 2,900 2,750 35,000 85

As discussed above, DOE used commercially available lamps when possible and their 

associated rated efficacies (catalog initial lumen output divided by the ANSI rated wattage) at 35 

°C to determine the initial CSL. DOE then adjusted the CSL to take into account the efficacy at 

25 °C. To establish the minimum efficacy requirements for each CSL, DOE also considered data 

submitted to DOE by manufacturers to demonstrate compliance with existing energy 

conservation standards. DOE determined if any adjustments were necessary to the initial CSL to 

CSL1

102.0

104.0

106.0

108.0

110.0

112.0

114.0

116.0

118.0

20 22 24 26 28 30

Catalog Rated Efficacy (lm/W)

ANSI Rated Wattage (W)
5-36

account for compliance efficacies of representative units and/or equivalent lamps. DOE 

considered equivalent lamps to be manufacturer-identified cross references of the representative 

units or lamps deemed to have equivalent characteristics. 

By examining publicly available compliance reports, DOE found that approximately 33 

percent of available 4-foot T5 MiniBP SO lamps had compliance information. Using this 

information, DOE was able to confirm that all representative units and/or equivalent lamps 

complied. Thus, based on compliance information, DOE determined that no adjustment to CSL 1 

was necessary. Figure 5.3.8 summarizes all available compliance information by lamp design 

(i.e., 800 series, reduced wattage, and improved 800 series) and the resulting CSL. 

Figure 5.3.8 All Compliance Report Data for 4-foot T5 MiniBP SO GSFLs with CCTs ≤ 

4,500 K, at 25 °C 

Table 5.3.30 summarizes the final efficacy requirement at CSL 1. 

Table 5.3.30 CSL 1 for 4-foot T5 MiniBP SO GSFLs with CCTs ≤ 4,500 K 

Candidate Standard Level Efficacy Requirement

lm/W

CSL 1 98.2

92.0

94.0

96.0

98.0

100.0

102.0

104.0

106.0

20 22 24 26 28 30

Compliance Efficacy (lm/W)

ANSI Rated Wattage (W)

800 Series

Reduced Wattage

Improved 800 Series

CSL1
5-37

Engineering Summary

The first set of results present the lamp replacement scenario for the 4-foot T5 MiniBP SO representative product class. In this 

scenario, energy savings are achieved through the use of higher efficacy, reduced wattage lamps. As stated in section 5.3.4, 

replacement lamp options were selected so that the system mean lumen output was within 10 percent of the baseline. Table 5.3.31

presents the engineering analysis results for two-lamp 4-foot T5 MiniBP SO PS systems operating in the commercial and industrial 

sectors. 

Table 5.3.31 Lamp Replacement Engineering Analysis for a Two-Lamp Programmed Start 28 W T5, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T5 28 27.8 104.3 2,900 2,697 30,000 2 PS 1.00 60.4 92.1 5,800 5,394

CSL 1 T5 26 26 111.5 2,900 2,660 25,000 2 PS 1.00 56.6 91.9 5,800 5,320

CSL 1 T5 25 25 116.0 2,900 2,750 35,000 2 PS 1.00 54.5 91.8 5,800 5,500

The next set of engineering results present the lamp-and-ballast replacement scenario for the 4-foot T5 MiniBP SO 

representative product class. For this scenario, as stated in section 5.3.5, the ballast with the lowest possible BF was selected that still 

maintained system mean lumen output within 10 percent of the baseline system. Table 5.3.32 presents the engineering analysis results 

for the replacement lamp-and-ballast combinations for two-lamp 4-foot T5 MiniBP SO PS systems in the commercial and industrial 

sectors. 
5-38

Table 5.3.32 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Programmed Start 28 W T5, 4,100 K 

System in the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T5 28 27.8 104.3 2,900 2,697 30,000 2 PS 1.00 60.4 92.1 5,800 5,394

CSL 1 T5 28 27.8 109.7 3,050 2,898 30,000 2 PS 0.95 57.9 91.2 5,795 5,506

CSL 1 T5 26 26 111.5 2,900 2,660 25,000 2 PS 0.95 54.3 91.0 5,510 5,054

CSL 1 T5 25 25 116.0 2,900 2,750 35,000 2 PS 0.95 52.3 90.9 5,510 5,225
5-39

5.3.6.5 Four-Foot T5 MiniBP HO GSFLs with CCTs ≤ 4,500 K 

Baseline Lamps

DOE selected baseline lamps as reference points from which to measure changes 

resulting from potential energy conservation standards. As discussed in section 5.2, a baseline 

lamp is typically the most common, least efficacious lamp sold in a given product class. To 

determine energy savings and changes in price, DOE compared representative lamps at each 

higher efficacy level with the baseline unit. 

DOE considered a number of criteria when selecting which commercially available lamp 

would serve as a baseline. The most popular wattage associated with the 4-foot T5 MiniBP HO 

product class is 54 W. Therefore, DOE selected a 54 W 4-foot T5 MiniBP HO lamp as a 

baseline. For the 54 W 4-foot T5 MiniBP HO baseline lamp, DOE identified typical performance 

characteristics. The T5 MiniBP HO lamps that are in this product class exclusively utilize 800 

series rare earth phosphors. DOE selected a CCT of 4,100 K because it is the most common CCT 

for this lamp type. The rated lifetime for these lamps is 24,000 hours when paired with a PS

ballast. 

Typically, a baseline product is a unit that just meets the existing energy conservation 

standard for the product (76 lm/W for this product class). DOE identified a lamp with an efficacy 

of 92.9 lm/W at 35 °C (83.6 lm/W at 25 °C, the temperature at which lamps are tested for 

compliance) because it is the most common, least efficacious 4-foot T5 MiniBP HO lamp. Table 

5.3.33 lists the characteristics of the 54 W 4-foot T5 MiniBP HO baseline lamp. 

Table 5.3.33 Baseline Lamp for the 4-foot T5 MiniBP High Output Representative Product 

Class

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output (at 

35 °C)

Mean 

Lamp 

Light 

Output (at 

35 °C)

Rated Life 

CRI

CCT

W W lm/W lm lm hr K

T5 54 53.8 92.9 5,000 4,850 24,000 82 4,100

Candidate Standard Levels and More Efficacious Substitutes

The following discussion identifies the steps and technologies associated with the CSL 

DOE considered for the 4-foot T5 MiniBP HO representative product class. DOE is aware that 

many T5 MiniBP HO lamps are operated at 35 °C and all manufacturers report performance at 

35 °C in their catalogs. Therefore, DOE selected more efficacious replacements and developed 

initial CSLs for T5 MiniBP HO lamps based on 35 °C catalog data. However, The DOE test 

procedure for T5 lamps requires the lamps to be tested at 25 °C. Because the test procedure is 

used to determine compliance with DOE energy conservation standards, DOE adjusted the CSLs 

to account for the efficacy at 25 °C. Specifically, when operated at 25 °C, the lumen output of T5 

lamps is approximately 10 percent lower than the lumen output of such lamps when operated at 
5-40

35 °C. DOE also utilized certain manufacturers’ catalog information if performance 

characteristics were provided for lamp operation at 25 °C. 

For this product class, DOE found that only one level of efficiency for full wattage (54 

W) lamps exists on the market today. However, DOE identified several more efficacious, 

reduced wattage lamps at higher efficacy levels. As mentioned previously, because full and 

reduced wattage lamps are not interchangeable in all applications, DOE has decided to ensure 

that full wattage lamps can meet each CSL considered. Because there are no commercially 

available full wattage higher efficacy replacements for the 4-foot T5 MiniBP HO baseline lamps, 

DOE modeled a more efficacious full wattage lamp. DOE created a higher efficacy model lamp 

by using a commercially available reduced wattage T5 MiniBP HO lamp more efficacious than 

the baseline lamp to scale to a full wattage T5 MiniBP HO lamp of comparable efficacy. The 

design options utilized in the model lamp, such as higher efficiency phosphors, are the same 

design options utilized in commercially available reduced wattage T5 MiniBP HO lamps that are 

more efficient than the baseline lamp. For further information on the development of the 

improved 54 W T5 MiniBP HO lamp, see appendix 5A of this TSD. 

In general terms, DOE based CSL 1 on the design options described below. Because 

utilizing higher efficiency phosphors is the most common method to achieve higher efficacies, 

DOE describes the phosphor technology associated with the CSL: 

CSL 1: This level is represented by a modeled higher efficacy 4-foot T5 MiniBP HO 

lamp that uses improved 800 series phosphors. Several reduced wattage lamps also meet this 

level. Specifically, a reduced wattage 50 W lamp (with a rated efficacy of 100.0 lm/W at 35 °C 

operation) and a reduced wattage 47 W lamp (with a rated efficacy of 102.1 lm/W at 35 °C) meet 

this level. This level represents max tech, the most efficacious products available today. 

DOE developed an initial CSL based on the efficacy of the modeled 54 W T5 HO, as 

well as catalog values of more efficacious lamps identified as representative units. The existing 

energy conservation standard (the July 2012 standards) is 76 lm/W (at 25 °C). Figure 5.3.9

illustrates the initial CSL for this rulemaking on a plot of the efficacies of the representative 

lamps at 35 °C. The square box identifies the baseline lamp. The plot also shows the more 

efficacious substitutes DOE considered as replacement lamps, including the improved full 

wattage model lamp denoted by a circle. Some of the representative units shown on the plot are 

at the same wattage as the baseline, but have a higher efficacy; others have a combination of 

lower wattage and higher efficacy. 
5-41

Figure 5.3.9 Candidate Standard Level for 4-foot T5 MiniBP HO GSFLs with CCTs ≤ 

4,500 K, at 35 °C 

Table 5.3.34 provides detailed information on the 4-foot T5 MiniBP HO representative 

lamps used in the engineering analysis and subsequent analyses. 

Table 5.3.34 4-foot T5 MiniBP HO Representative Lamps 

CSL Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp

Light 

Output (at 

35 °C)

Mean 

Lamp

Light 

Output (at 

35 °C)

Rated Life

CRI

W W lm/W lm lm hr

Baseline T5 54 53.8 92.9 5,000 4,850 24,000 86

1 T5 54 53.8 97.3 5,237 4,871 30,000 82

1 T5 50 50.0 100.0 5,000 4,650 30,000 85

1 T5 47 47.0 102.1 4,800 4,410 30,000 84

As discussed above, DOE used commercially available lamps, when possible, and their 

associated rated efficacies (catalog initial lumen output divided by the ANSI rated wattage) at 35 

°C to determine the initial CSL. DOE then adjusted the CSL to take into account the efficacy at 

25 °C. To establish the minimum efficacy requirements for each CSL, DOE also considered data 

submitted to DOE by manufacturers to demonstrate compliance with existing energy 

conservation standards. DOE determined if any adjustments were necessary to the initial CSL to 

CSL1

92.0

94.0

96.0

98.0

100.0

102.0

104.0

40 45 50 55 60

Catalog Rated Efficacy (lm/W)

ANSI Rated Wattage (W)
5-42

account for compliance efficacies of representative units and/or equivalent lamps. DOE 

considered equivalent lamps to be manufacturer-identified cross references of the representative 

units or lamps deemed to have equivalent characteristics. 

By examining publicly available compliance reports, DOE found that approximately 37 

percent of available 4-foot T5 MiniBP HO lamps had compliance information. Using this 

information, DOE was able to confirm that the reduced wattage representative units and/or 

equivalent lamps complied with CSL 1. Thus, based on compliance information, DOE 

determined that no adjustment to CSL 1 was necessary. Figure 5.3.10 summarizes all available 

compliance information by lamp design (i.e., 800 series and reduced wattage) and the resulting 

CSL. 

Figure 5.3.10 All Compliance Report Data for 4-foot T5 MiniBP HO GSFLs with CCTs ≤ 

4,500 K, at 25 °C 

Table 5.3.35 summarizes the final efficacy requirement at CSL 1. 

Table 5.3.35 CSL 1 for 4-foot T5 MiniBP HO GSFLs with CCTs ≤ 4,500 K 

Candidate Standard Level Efficacy Requirement

lm/W

CSL 1 86.2 lm/W

80

82

84

86

88

90

92

94

96

98

40 45 50 55 60

Compliance Efficacy (lm/W)

ANSI Rated Wattage (W)

800 Series

Reduced Wattage

Model Lamp

CSL1
5-43

Engineering Summary

The first set of results present the lamp replacement scenario for the 4-foot T5 MiniBP HO representative product class. In this 

scenario, energy savings are achieved through the use of higher efficacy, reduced wattage lamps. As stated in section 5.3.4, 

replacement lamp options were selected so that the system mean lumen output was within 10 percent of the baseline. Table 5.3.36

presents the engineering analysis results for two-lamp 4-foot T5 MiniBP HO PS systems operating in the commercial and industrial 

sectors. 

Table 5.3.36 Lamp Replacement Engineering Analysis for a Two-Lamp Programmed Start 54 W T5, 4,100 K System in the 

Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T5 54 53.8 92.9 5,000 4,850 24,000 2 PS 1.00 116.5 92.4 10,000 9,700

CSL 1 T5 50 50 100.0 5,000 4,650 30,000 2 PS 1.00 108.5 92.2 10,000 9,300

CSL 1 T5 47 47 102.1 4,800 4,410 30,000 2 PS 1.00 102.2 92.0 9,600 8,820

The next set of engineering results present the lamp-and-ballast replacement scenario for the 4-foot T5 MiniBP HO 

representative product class. For this scenario, as stated in section 5.3.5, the ballast with the lowest possible BF was selected that still 

maintained system mean lumen output within 10 percent of the baseline system. For this product class, DOE could not consider 

installing a lamp on a lower BF ballast to save energy, as ballasts with a BF lower than 1.0 are not commercially available. Table 

5.3.37 presents the engineering analysis results for the replacement lamp-and-ballast combinations for two-lamp 4-foot T5 MiniBP 

HO PS systems in the commercial and industrial sectors. 
5-44

Table 5.3.37 Lamp-and-Ballast Replacement Engineering Analysis for a Two-Lamp Programmed Start 54 W T5, 4,100 K 

System in the Commercial and Industrial Sectors 

Efficacy 

Level

Lamp 

Diameter

Nominal 

Wattage

Rated 

Wattage

Rated 

Efficacy

Initial 

Lamp 

Light 

Output

Mean 

Lamp 

Light 

Output

Rated

Life

Number 

of 

Lamps

Starting

Method

Ballast 

Factor

System 

Input 

Power BLE

System 

Initial 

Light 

Output

System 

Mean 

Light 

Output

W W lm/W lm lm hr W lm lm

Baseline T5 54 53.8 92.9 5,000 4,850 24,000 2 PS 1.00 116.5 92.4 10,000 9,700

CSL 1 T5 54 53.8 97.3 5,237 4,871 30,000 2 PS 1.00 116.5 92.4 10,474 9,741

CSL 1 T5 50 50 100.0 5,000 4,650 30,000 2 PS 1.00 108.5 92.2 10,000 9,300

CSL 1 T5 47 47 102.1 4,800 4,410 30,000 2 PS 1.00 102.2 92.0 9,600 8,820
5-45

5.3.7 Scaling to Product Classes Not Analyzed 

DOE identified and selected certain product classes as representative product classes on 

which to concentrate its analytical effort. DOE chose these representative product classes 

primarily due to their high market volumes. The following sections discuss how DOE scaled 

CSLs from the analyzed product classes to those product classes not directly analyzed. 

5.3.7.1 2-foot U-Shaped GSFLs with CCTs ≤ 4,500 K 

DOE utilized the 4-foot MBP linear fluorescent products to scale to the 2-foot U-shaped 

products, as both products use the same fluorescent technology, span the same range of wattages, 

and, without its bent curve, the 2-foot U-shaped would be approximately the same length as the 

4-foot MBP linear lamp. DOE reviewed manufacturer catalogs containing commercially 

available 2-foot U-shaped lamps with CCTs less than or equal to 4,500 K and determined the 

equivalent 4-foot MBP version (i.e., the only difference between the two lamp types is shape). 

By comparing catalog ratings for 2-foot U-shaped lamps with equivalent 4-foot MBP lamps, 

DOE determined an average efficacy reduction for the 2-foot U-shaped lamps from the 4-foot 

MBP lamps was appropriate. Therefore, DOE reduced CSL 1 and CSL 2 by 2 percent to 88.2 

lm/W and 91.1 lm/W, respectively. DOE confirmed that the scaled standard levels resulted in a 

similar technology impact at each CSL (see 5.3.6.1 for these technology impacts). DOE also 

confirmed that the scaling factor did not result in backsliding from the current standards. Table 

5.3.38 shows the efficacy levels for these lamps. 

Table 5.3.38 Efficacy Requirements for 2-foot U-Shaped Lamps with CCTs Less Than or 

Equal To 4,500 K 

CSL

Efficacy Requirement (lm/W)

Reduction 4-foot MBP 2-foot U-Shaped

1 90.0 88.2 2%

2 93.0 91.1 2%

5.3.7.2 Lamps with CCTs Above 4,500 K 

As discussed in 5.3.1, DOE is not analyzing GSFLs with CCTs above 4,500 K. As stated 

in the market and technology assessment (see chapter 3 of this TSD), the efficacy of higher CCT 

lamps is lower due to the quality of the blue light emitted. Based on manufacturer feedback that 

the effect of CCT on efficacy is independent of product type, DOE chose to develop one scaling 

factor to apply across all product classes to account for the difference in efficacy between lamps 

with a CCT less than or equal to 4,500 K and greater than 4,500 K. 

DOE identified pairs of lamps in which the only difference between the lamps was the 

CCT. DOE compared commercially available lamps at 4,100 K and 5,000 K, and 4,100 K and 

6,500 K to determine differences in efficacy. DOE then calculated the average difference in 

efficacy of all lamp pairs and determined a 2 percent reduction of the CSLs established for the 

less than or equal to 4,500 K representative product classes was appropriate. Two percent is also 

the largest scaling factor that can be applied across all product classes without backsliding. 
5-46

For the 2-ft U-shaped product class with CCT greater than 4,500 K, DOE applied the 2 

percent reduction to the scaled CSLs for the 2-ft U-shaped product class. DOE confirmed that the 

scaled standard levels resulted in similar technology impacts at each CSL. Table 5.3.39 shows 

the efficacy levels for these lamps. 

Table 5.3.39 Efficacy Requirements for Product Classes with CCTs Greater Than 4,500 K 

Product Class CSL

Efficacy Requirement

lm/W Reduction

≤ 4,500 K > 4,500 K

4-foot MBP

1 90.0 88.2 2%

2 93.0 91.1 2%

8-foot SP slimline 1 99.0 97.0 2%

8-foot RDC HO 1 97.0 95.1 2%

4-foot T5 MiniBP SO 1 98.2 96.2 2%

4-foot T5 MiniBP HO 1 86.2 84.5 2%

2-ft U-shaped

1 88.2 86.4 2%

2 91.1 89.3 2%

5.3.8 Summary of All Candidate Standard Levels for Covered GSFLs

Table 5.3.40 shows a summary of CSLs for all GSFLs covered by this rulemaking. 

“N/A” is shown where no CSLs exist. Representative product classes are indicated by gray 

shading. 

Table 5.3.40 Summary of All Candidate Standard Levels for Covered GSFLs 

CCT Lamp Type

Candidate Standard Level

1 2

≤ 4,500 K

4-foot medium bipin 90.0 93.0

2-foot U-shaped 88.2 91.1

8-foot single pin slimline 99.0 N/A

8-foot recessed double contact HO 97.0 N/A

4-foot T5 miniature bipin SO 98.2 N/A

4-foot T5 miniature bipin HO 86.2 N/A

> 4,500 K

4-foot medium bipin 88.2 91.1

2-foot U-shaped 86.4 89.3

8-foot single pin slimline 97.0 N/A

8-foot recessed double contact HO 95.1 N/A

4-foot T5 miniature bipin SO 96.2 N/A

4-foot T5 miniature bipin HO 84.5 N/A
5-47

5.4 INCANDESCENT REFLECTOR LAMPS 

5.4.1 Representative Product Classes 

As discussed in the market and technology assessment (chapter 3 of this TSD), DOE is 

considering eight separate IRL product classes based on three class-setting factors: spectrum, 

diameter, and input voltage. Of these product classes, DOE chose the standard spectrum, voltage 

less than 125 V, diameter greater than 2.5 inches product class as representative due to the 

prevalence of these lamps in the market. Information from manufacturer interviews and a review 

of product catalogs revealed that standard spectrum lamps represent the vast majority of IRLs. 

DOE research and manufacturer feedback also indicated that IRLs with diameters greater than 

2.5 inches are more common that those with smaller diameters; specifically, the majority of 

consumers purchase parabolic aluminized reflector (PAR)30 or PAR38 IRLs. Additionally, DOE 

found that most consumers purchase IRLs rated at 120 V. 

Table 5.4.1 lists the eight product classes and identifies the representative product class 

that DOE is considering in this preliminary analysis. 

Table 5.4.1 Product Classes for Incandescent Reflector Lamps 

Lamp Type Diameter Voltage

Standard spectrum

> 2.5 inches

≥ 125 

< 125 (representative)

≤ 2.5 inches

≥ 125

< 125

Modified spectrum

> 2.5 inches

≥ 125

< 125

≤ 2.5 inches

≥ 125

< 125

5.4.2 Baseline Lamps 

For each representative product class, DOE selects baseline lamps that are typically the 

most common, least efficacious lamps that meet standards. When necessary, DOE selects 

multiple baseline lamps to ensure consideration of different high volume lamps and their 

associated consumer economics. To identify baseline lamps, DOE reviews product offerings in 

catalogs, shipment information, and manufacturer feedback obtained during interviews. 

DOE selected baseline lamps as reference points from which DOE measured changes 

resulting from potential energy conservation standards. To determine energy savings and 

changes in price, DOE compared representative lamps at each higher efficacy level with the 

baseline units. DOE considered a number of criteria when selecting which commercially 

available lamp would serve as a baseline. First, DOE selected a PAR38 lamp as the baseline 

based on the diameter’s high shipment volume. Then, DOE identified typical characteristics for 
5-48

these types of lamps (i.e., wattage, lifetime, lumen package, and rated efficacyn). Among all 

PAR38 lamps with the most common characteristics, DOE selected two lamps that just met 

existing standards as baselines. One is a halogen lamp with a lifetime of 1,500 hours that utilizes 

a higher efficiency inert fill gas and a higher efficiency reflector coating. The other is an HIR 

lamp with a lifetime of 3,000 hours that utilizes IR glass coatings. Because these lamps comprise 

two distinct technologies and therefore have different LCCs, DOE analyzed both lamps as 

baselines. 

A summary of the IRL baseline lamps selected for the representative product class is 

shown in Table 5.4.2. 

Table 5.4.2 IRL Baseline Lamps 

Representative Product 

Class

Baseline Lamps

Lamp 

Type Descriptor

Wattage Efficacy Initial Light 

Output Lifetime

W lm/W lm hr

Standard Spectrum,

Voltage < 125 V,

Diameter > 2.5 Inches

PAR38 Improved Halogen 60 17.8 1,070 1,500

PAR38 HIR 60 18.3 1,100 3,000

5.4.3 More Efficacious Substitutes 

After choosing a baseline lamp for each representative product class, DOE identifies 

commercially available IRLs that can serve as more efficacious substitutes. When identifying 

substitutes, DOE used catalog efficacy values to identify higher efficacy replacement lamps. 

DOE selected more efficacious replacement lamps that both save energy and maintain 

comparable light output when possible. Similar to GSFLs, consumers take lumen package into 

consideration when purchasing IRLs. Therefore, DOE analyzed commercially available, reduced 

wattage lamps that maintain light output within 10 percent of the baseline. 

In reviewing published catalog data, DOE observed that a higher efficacy, reduced 

wattage lamp, referred to in this preliminary analysis as an improved HIR lamp, can serve as a 

substitute for both baseline lamps. The reduced wattage design utilizes HIR technology, which 

refers to glass coatings that reflect infrared light, as well as a higher efficiency reflector coating, 

which are discussed in chapter 3 of this TSD. 

5.4.4 Candidate Standard Levels 

 DOE adopted an equation-based approach to establish CSLs for IRLs, reflecting the 

relationship between efficacy and wattage. DOE developed a continuous equation that specifies a 

minimum efficacy requirement across wattages and represents the potential efficacy a lamp 

achieves using a particular design option. The technology contour line represents the same IRL 

design option across the wattage range of the entire product class. For example, the CSL based 

 

n

 For IRLs, the rated efficacy is the catalog initial lumen output divided by catalog wattage. 
5-49

on an improved HIR lamp is a curve rather than a step function, and denotes an improved HIR 

standard at all wattages. 

For IRLs in the representative product class, DOE observed a natural efficacy division in 

the marketplace corresponding to the design option utilized to increase lamp efficacy. DOE 

considered this efficacy division in selecting a CSL by using the efficacies of commercially 

available lamps as a guide. DOE selected representative units for each CSL. 

 DOE also observed lifetime changes for different technologies. For example, a halogen 

lamp typically has a lifetime of around 1,500 hours, while an HIR lamp typically has a lifetime 

of 3,000 hours. DOE considered the possibility that manufacturers would produce lamps with a 

shorter lifetime than the baseline lamps in order to increase efficacy. To account for this 

scenario, DOE determined performance characteristics and prices for model lamps that meet 

CSL 1 by shortening lifetime rather than using more efficient design options. To calculate the 

performance characteristics of these model lamps, DOE calculated the minimum lumens 

necessary to meet CSL 1 for a lamp with the same wattage as the baseline lamps. DOE then 

calculated the shortened lifetime necessary for each baseline lamp to achieve the minimum 

lumen output by using equations from the Illuminating Engineering Society of North America 

(IESNA) Lighting Handbook1

that relate lifetime, lumens, and wattage. DOE assumed that the 

cost of each lamp with a shortened lifetime at CSL 1 was equivalent to the cost of the baseline 

lamp because the lamps would utilize the same technology. These modeled lamps were 

incorporated in shortened lifetime scenarios analyzed in the shipment analysis (see chapter 9 of 

this TSD) and as a sensitivity in the LCC analysis (see appendix 8B of this TSD). 

In general terms, DOE based CSL 1 on the following design options: 

CSL 1: This candidate standard level can be achieved by improved HIR lamps that may 

utilize improvements in reflector coatings. This level is based on an HIR lamp with a lifetime of 

4,400 hours. 

DOE developed an initial CSL based on catalog values of the more efficacious lamp that 

DOE selected to analyze as a representative unit. Figure 5.4.1 plots the results of the engineering 

analysis for the baseline lamps along with the initial CSL based on catalog efficacies. Square 

boxes represent the two baseline lamps in the plot; the triangle represents the higher efficacy 

lamp design. As indicated in Figure 5.4.1, the lamp design for the more efficacious substitute is 

higher in efficacy and lower in wattage than the baseline lamp, but maintains the light output of 

the baseline lamp. 
5-50

Figure 5.4.1 Initial Candidate Standard Level for Standard Spectrum, Large Diameter, 

Low Voltage IRLs 

Table 5.4.3 provides detailed information on the IRL representative lamps used in the 

engineering analysis and subsequent analyses. 

Table 5.4.3 IRL Representative Lamps 

Efficacy 

Level Lamp Type Descriptor

Wattage Efficacy

Initial 

Light 

Output

Lifetime

W lm/W lm hr

Baseline 1 PAR38 Improved Halogen 60 17.8 1,070 1,500

Baseline 2 PAR38 HIR 60 18.3 1,100 3,000

CSL 1 PAR38 Improved HIR 55 20.0 1,100 4,400

DOE also reviewed publicly available lamp efficacy data submitted to DOE by 

manufacturers to show compliance with existing energy conservation standards.o By analyzing 

 

o

 The publicly available compliance information for IRLs can be found in DOE’s Compliance Certification Database 

available here: www.regulations.doe.gov/certification-data/. 
5-51

manufacturer compliance reports, DOE found that efficacies of lamps when reported for the 

purpose of compliance often vary from catalog values. 

Because the compliance requirements for IRLs require the reported efficacy to be the 

lower of the average efficacy or the lower confidence limit divided by 0.97 and also impose 

specific sampling requirements, the efficacy reported for compliance may be different from the 

rated efficacy reported in catalogs. Therefore, DOE adjusted the initial CSL for IRLs such that 

commercially available IRLs using design options represented by the CSL would comply with 

the CSL. Specifically, DOE adjusted CSL 1 based on the reported efficacy of a PAR38 improved 

HIR lamp. Figure 5.4.2 presents the compliance report data used to develop the IRL CSL. The 

triangle indicates the representative unit. DOE notes that there is a limited amount of publicly 

available compliance information for lamps covered under this rulemaking. DOE found there to 

be compliance data for only 36 percent of covered IRL products compliant with the July 2012 

standards. In addition, manufacturers indicated during interviews that new products are being 

introduced into the market that have not yet been tested for compliance. 

Figure 5.4.2 Compliance Report Data for Standard Spectrum, Large Diameter, Low 

Voltage IRLs 

Table 5.4.4 summarizes the resulting efficacy requirements at CSL 1 after accounting for 

compliance report data. 
5-52

Table 5.4.4 CSL 1 for Standard Spectrum, Large Diameter, Low Voltage IRLs 

Candidate Standard Level Efficacy Requirement

lm/W

CSL 1 6.2P0.27

P = rated wattage

5.4.5 Scaling to Product Classes Not Analyzed 

DOE identified and selected a representative product class on which to concentrate its 

analytical effort. DOE considered this product class as representative primarily due to its high 

market volume. The following sections discuss how DOE scaled CSLs from the analyzed 

product class to those product classes not directly analyzed. 

5.4.5.1 Modified Spectrum 

DOE did not directly analyze modified spectrum IRLs, but established CSLs for this 

product class by scaling from the CSLs developed for the standard spectrum product class. DOE 

developed a relationship between the performance of standard spectrum and modified spectrum 

IRLs. As with higher CCT GSFLs, modified spectrum IRLs achieve their modified spectra 

through selective filtering, thereby inherently lowering their efficacies. Manufacturers achieve 

this specific spectrum in modified spectrum IRLs by applying a coating, or introducing 

neodymium or other additives into the cover glass of the IRL. Manufacturers may change the 

thickness of the coating or the content of neodymium to modify the spectrum to different 

degrees, and this modification changes the lumen output of the IRL. In the 2009 Lamps Rule, 

DOE assessed the efficacy differences between standard and modified spectrum IRLs by 

measuring the efficacies of commercially available standard and modified spectrum lamps. 74 

FR 34080 (July 14, 2009)p DOE correlated the measured color point data of the lamps with lamp 

light output reduction and lamp spectral power distribution. By analyzing the data, DOE 

established that a reduction of 15 percent from the standard spectrum CSLs would be appropriate 

for modified spectrum IRLs. 

DOE found a limited number of modified spectrum products on the market, but these 

lamps had an efficacy reduction of 15 percent from standard spectrum products. Thus, DOE is 

considering maintaining the reduction percentage for this rulemaking. See appendix 5B of this 

TSD for further details on DOE’s modified spectrum IRL analysis. Table 5.4.5 shows a summary 

of the CSL for modified spectrum IRLs with diameters greater than 2.5 inches and operating 

voltages less than 125 V.

Table 5.4.5 CSL 1 for Modified Spectrum, Large Diameter, Low Voltage IRLs 

CSL

Efficacy Requirement

lm/W Reduction

Standard Spectrum Modified Spectrum

1 6.2P0.27 5.3P0.27 15.0%

P = rated wattage

 

p

 Information regarding the 2009 Lamps Rule can be found on regulations.gov, docket number EERE-2006-STD0131 at www.regulations.gov/#!docketDetail;D=EERE-2006-STD-0131. 
5-53

5.4.5.2 Diameters Less Than or Equal To 2.5 Inches 

DOE did not directly analyze IRLs with diameters less than or equal to 2.5 inches but 

established CSLs for this product class by scaling from the CSLs developed for the IRL product 

class with diameters greater than 2.5 inches. DOE developed a relationship between the 

performance of small-diameter and large-diameter IRLs. A smaller-diameter IRL has an 

inherently lower optical efficacy than a larger-diameter lamp given a similar filament size. To 

determine an appropriate scaling factor for IRLs with diameters less than or equal to 2.5 inches, 

DOE examined the inherent efficacy differences between the PAR20 lamp (the most common 

IRL with a diameter less than or equal to 2.5 inches) and its PAR30 or PAR38 counterpart by 

comparing catalog efficacy data of each lamp type from several lamp manufacturers (all other 

features remaining approximately the same). DOE found that the reduction in efficacy caused by 

the smaller lamp diameter was approximately 12 percent for IRLs. 

DOE acknowledges that diameter may impact the type of capsule that is used within a 

lamp. Single-ended capsules feature a lead wire inside of the capsule that carries current between 

the filament and the electrical connection in the IRL’s base. The presence of this wire inside of 

the capsule prevents a certain amount of energy from reaching the capsule wall and being 

reflected (recycled) back to the capsule filament. Large-diameter IRLs with HIR technology may 

feature a double-ended HIR capsule. A double-ended burner features a lead wire outside of the 

capsule, where it does not interfere with the reflectance of energy from the capsule wall back to 

the capsule filament. However, the double-ended HIR capsule configuration does not generally 

fit into a PAR20 lamp due to its reduced size. Thus, DOE developed the efficacy requirements 

for small-diameter IRLs by assuming that the double-ended burner technology could not be used. 

In order to determine the efficacy reduction that would result from using a single-ended burner 

instead of a double-ended burner in a lamp, in the 2009 Lamps Rule DOE obtained a 

commercially available single-ended HIR capsule and measured the location of the lead wire 

inside of the capsule. DOE then developed a model that computed how much energy is prevented 

from being reflected against the capsule wall and recycled due to the “shadowing effect” of the 

lead wire inside of the capsule. DOE was also able to determine the slight change in IRL power 

consumption due to the reduction in energy recycling. Finally, DOE simulated manufacturing 

variability by modeling the effects of changing the capsule dimensions and lead wire positioning 

by small amounts. Using the modeled data, DOE computed that an efficacy reduction of 

approximately 3.5 percent would result from the usage of a single-ended burner instead of a 

double-ended burner in a lamp. 

Because DOE did not find small-diameter IRLs covered under this rulemaking that 

incorporate double-ended burners, DOE decided to continue to incorporate the scaling factor for 

single-ended burners in its analysis. This 3.5-percent reduction is in addition to the 12-percentlower optical efficacy for small-diameter IRLs compared to large-diameter IRLs. Therefore, 

DOE is considering a scaling factor of 15.5 percent with 12 percent based on the impact of the 

diameter and an additional 3.5 percent based on the use of less efficient single-ended burners in 

small-diameter lamps. Table 5.4.6 shows a summary of the CSL for standard spectrum IRLs with 

diameters less than or equal to 2.5 inches and operating voltages less than 125 V.
5-54

Table 5.4.6 CSL 1 for Standard Spectrum, Small Diameter, Low Voltage IRLs 

CSL

Efficacy Requirement

lm/W Reduction

≥ 2.5 Inches < 2.5 Inches

1 6.2P0.27 5.2P0.27 15.5%

P = rated wattage

5.4.5.3 Operating Voltages Greater Than or Equal to 125 Volts 

As discussed in chapter 3 of this TSD, DOE is considering separate product classes for 

lamps rated at 120 V and those rated at 130 V. DOE notes that most consumers operate 130 V 

lamps at 120 V, which slightly decreases their efficacy but increases their lifetime. In the 2009 

Lamps Rule, DOE developed a scaling factor for the 130 V product class that would require 130 

V lamps to use the same technology and possess the same general performance characteristics as 

120 V lamps operated at 120 V. DOE found that while there may be a slight decrease in efficacy, 

the lifetime of a 130 V lamp is doubled when it is operated at 120 V, giving it an advantage over 

120 V rated lamps. Therefore, using the IESNA Lighting Handbook2equations that relate 

lifetime, lumens, and wattage to voltage of incandescent lamps, DOE determined the increase in 

efficacy of 130 V rated lamps operated at 120 V if their additional lifetime over that of 120 V 

lamps were instead used to increase their efficacy. The equations DOE used from the IESNA 

Lighting Handbook are as follows: 

d

volts

VOLTS

LIFE

life

 )(

Eq. 5.1 

k

VOLTS

volts

LUMENS

lumens

 )(

Eq. 5.2

n

VOLTS

volts

WATTS

watts

 )(

Eq. 5.3

Capital letters represent normal rated values while lower-case letters represent changed 

values. By using published manufacturer literature on lumen, wattage, and voltage ratings, DOE 

found in the 2009 Lamps Rule that the most typical values for d, k, and n in the above equations 

for the IRLs analyzed are as follows: d=8.7, k=3.4, n=1.6. From this information and 

confidential information on incandescent lamp design, DOE determined that a 15 percent scaling 

factor was necessary. Therefore, DOE implemented a 15 percent increase to scale from the < 125 

V product class to the >125 V product class in the 2009 Lamps Rule. 

DOE believes that the analysis from the 2009 Lamps Rule is still applicable. Thus, DOE 

is considering maintaining the 15 percent increase in this rulemaking. Table 5.4.7 shows a 

summary of the CSL for standard spectrum IRLs with diameters greater than 2.5 inches and 

operating voltages greater than or equal to 125 V.
5-55

Table 5.4.7 CSL 1 for Standard Spectrum, Large Diameter, High Voltage IRLs 

CSL

Efficacy Requirement

lm/W Increase

< 125 Volts ≥ 125 Volts

1 6.2P0.27 7.1P0.27 15.0%

P = rated wattage

5.4.6 Summary of All Candidate Standard Levels for Covered IRLs 

In analyzing commercially available IRLs, DOE found each scaling factor (spectrum, 

diameter, and voltage) to be independent. To scale from the representative product class to a 

scaled product class, DOE applied each scaling factor that corresponded to the differences 

between the two classes by multiplying the representative product class coefficient by all 

applicable scaling factors and rounding the result. Table 5.4.8 shows a summary of the CSLs for 

all IRLs covered by this rulemaking. The representative IRL product class is indicated by gray 

shading. 

Table 5.4.8 Summary of Candidate Standard Levels for Covered IRLs 

Lamp Type Diameter Voltage CSL 1

Standard

spectrum

> 2.5 inches

≥ 125 V

7.1P

0.27

< 125 V 6.2P

0.27

≤ 2.5 inches

≥ 125 V 6.0P

0.27

< 125 V 5.2P

0.27

Modified

spectrum

> 2.5 inches

≥ 125 V 6.1P

0.27

< 125 V 5.3P

0.27

≤ 2.5 inches

≥ 125 V 5.1P

0.27

< 125 V 4.5P

0.27

P = rated wattage 
5-56

REFERENCES 

1 Rea, M. S., ed., The IESNA Lighting Handbook: Reference and Application, 9th Edition. New 

York: Illuminating Engineering Society of North America. IESNA (2000). 

2

 Ibid.