APPENDIX 5B. T5 HALOPHOSPHOR MINIATURE BIPIN BASELINE LAMPS

TABLE O F CONTENTS

**5B.1 I**  **NTRODUCTION**

**.................................. .......................................................................5B­1** 

**5B.2 H**  **ALOPHOSPHOR T5**  **MARKET ................................................................................5B­1** 

**5B.3 LI**  **NEAR G**  **ENERAL SERVICE**  **FLUORESCENT LAMP**  **OVERVIEW....................5B­2**

**5B.4 M**  **ODEL F**  **ORMULATION, INPUTS,**  **AND ANALYTICAL**  **RESULTS ...................5B­3** 

**5B.4.1 2**  **8W 4**  **­foot T5**  **Miniature Bipin**  **(MiniBP) SO**  **Halophosphor Baseline**  **......5B­3**

**5B.4.2 5**  **4W 4**  **­foot T5**  **MiniBP HO**  **Halophosphor Baseline...................................5B­5** 

**REFERENCES**

**.......................................................................................................................... 5B­6** 

LIST O F TABLES

**Table 5**  **B.1 T5**  **Halophosphor Lamps**  **in the**  **Current Market.....................................................5B­2** 

**Table 5B.2:**  **4­foot T5**  **SO Lamps**  **Analyzed ..............................................................................5B­5** 

**Table 5B.3:**  **4­foot T5**  **HO Lamps**  **Analyzed .............................................................................5B­5** 

LIST O F FIGURES

**Figure 5**  **B.1: A**  **Common Linear**  **General Service**  **Fluorescent Lamp**  **in Operation**  **..................5B­2**

**Figure 5B.2:**  **Lamp Efficacy**  **Vs. Lamp**  **Length For**  **Cool White**  **Halophosphor Preheat**  **T5**

**Fluorescent L**  **amps.......................................................................................5B­4**

**5B­i**APPENDIX 5B. T5 HALOPHOSPHOR MINIATURE BIPIN BASELINE LAMPS

5B.1 I NTRODUCTION

**T5 lamps**  **c urrently**  **on the**  **United States**  **market exist**  **in a**  **variety of**  **lengths and**  **wattages.**

**DOE’s market**  **research indicates**  **that the**  **primary driver**  **of T5**  **market growth,**  **however, is** 

**substitution for**  **currently regulated**  **four­foot medium**  **bipin (MBP)**  **lamps of**  **other diameters,** 

**such as**  **T8 and**  **T12 lamps.**  **Manufacturers stated**  **that the**  **most popular**  **wattages of**  **four­foot T5** 

**lamp are**  **currently 28W**  **for standard**  **output (SO)**  **T5 and**  **54W for**  **high output**  **(HO) T5.** 

**Reduced wattage**  **SO and**  **HO T5**  **lamps (of**  **26W and**  **51W, respectively)**  **are also**  **sold.**

**Most T5**  **are efficacious**  **lamps that**  **use rare­earth**  **phosphors. Several**  **stakeholders in**  **this**

**rulemaking have**  **commented, however,**  **that less­efficacious**  **T5 lamps,**  **particularly those**  **using**

**1 halophosphors,**  **may enter**  **the US**  **market. (Public**  **Meeting Transcript,**  **No. 21**  **at pp.**  **71–73)**

**Because DOE**  **believes that**  **consumers will**  **purchase low­efficacy**  **4­foot T5**  **lamps without**  **a T5** 

**standard if**  **such lamps**  **are brought**  **to market,**  **DOE developed**  **models of**  **4­foot halophosphor**  **T5**

**SO and**  **HO lamps**  **as baselines**  **for the**  **SO and**  **HO T5**  **product classes,**  **respectively. This** 

**appendix details**  **the development**  **of those**  **models. In**  **particular, DOE**  **developed models**  **of a** 

**28W halophosphor**  **SO lamp**  **and a**  **54W halophosphor**  **HO lamp**  **to represent**  **the most**  **popular**

**wattages of**  **4­foot rare­earth**  **phosphor T5**  **lamps currently**  **commercially available**  **in the**  **US.**

5B.2 H ALOPHOSPHOR T5 MARKET

**DOE s**  **urveyed the**  **current market**  **of T5**  **halophosphor lamps**  **and found**  **that only**  **SO**

**halophosphor T5**  **lamps of**  **lengths shorter**  **than four**  **feet are**  **commercially available.**  **These**

**lamps use**  **one of**  **two types**  **of halophosphors:**  **cool­white and**  **warm­white, with**  **the cool­white** 

**lamps having**  **a slightly**  **lower efficacy.**  **Information on**  **the commercially**  **available halophosphor** 

**T5 lamps**  **is shown**  **in Table**  **5B.1. Light**  **output refers**  **to the**  **lumens produced**  **by the**  **lamp after** 

**100 hours**  **of initial**  **operation (“seasoning”).** 

**Because n**  **one of**  **the available**  **T5 halophosphor**  **lamps have**  **wattages, lumen**  **outputs,**

**rated lifetimes,**  **or lengths**  **that are**  **similar to**  **4­foot T5**  **rare­earth phosphor**  **GSFL, DOE**  **created a** 

**methodology for**  **generating 4­foot**  **T5 halophosphor**  **lamps based**  **on the**  **available market**  **data**

**and the**  **physical principles**  **of fluorescent**  **lamp operation.**  **DOE investigated**  **the possible** 

**relationship between**  **lamp length**  **and efficacy**  **to develop**  **a lamp**  **model, which**  **is described** 

**below.**

**1 A**  **notation in**  **the form**  **‘‘Public Meeting**  **Transcript, No.**  **21 at**  **pp. 71–73’’**  **identifies a**  **written comment**  **that DOE** 

**has received**  **and has**  **included in**  **the docket**  **of this**  **rulemaking. This**  **particular notation**  **refers to**  **a comment:**  **(1)**

**submitted during**  **the public**  **meeting on**  **March 10­11,**  **2008; (2)**  **in document**  **number 21**  **in the**  **docket of**  **this**

**rulemaking; and**  **(3) appearing**  **on pages**  **71 through**  **73 of**  **the transcript.** 

**5B­1**Table 5B.1 T5 Halophosphor Lamps in the Current Market

Manufacturer Model L i ght

O utput Nominal

P ower Nominal

L ength Rated L ife Efficacy

l m W in hrs l m/W

**A t**  **ech L**  **ighting 4WT**  **1 50**  **4 6**  **5000 3**  **7.5**

**G E**  **L ighting**  **F4T5/CW 1**  **35 4**  **6 5000**  **3 3.8** 

**O SRAM** 

**S ylvania**  **F4T5/ CW**  **1 35**  **4 6**  **6000 3**  **3.8**

**P hi**  **lips L**  **ighting F4T5/Soft**  **W hite**  **150 4**  **6 6000**  **3 7.5** 

**A t**  **ech L**  **ighting 6WT**  **3 00**  **6 9**  **5000 5**  **0.0**

**G E**  **L ighting**  **F6T5/CW 2**  **95 6**  **9 5000**  **4 9.2** 

**O SRAM** 

**S ylvania**  **F6T5/ CW**  **2 75**  **6 9**  **7500 4**  **5.8**

**P hi**  **lips L**  **ighting F6T5/Soft**  **W hite**  **325 6**  **9 7500**  **5 4.2** 

**A t**  **ech L**  **ighting 8WT**  **4 00**  **8 12**  **5 000**  **5 0.0** 

**G E**  **L ighting**  **F8T5/CW 4**  **00 8**  **12 5**  **000 5**  **0.0**

**O SRAM** 

**S ylvania**  **F8T5/ CW**  **4 00**  **8 12**  **7 500**  **5 0.0** 

**P hi**  **lips L**  **ighting F8T5/Soft**  **W hite**  **450 8**  **12 7**  **500 5**  **6.3**

**A t**  **ech L**  **ighting 13WT**  **8 50**  **1 3**  **2 1**  **5 000**  **6 5.4** 

**G E**  **L ighting**  **F13T5/WW 8**  **70 1**  **3 2**  **1 5**  **000 6**  **6.9**

**O SRAM** 

**S ylvania**  **F13T5/ WW**  **8 80**  **1 3**  **2 1**  **7 500**  **6 7.7** 

**P hi**  **lips L**  **ighting F13T5/Soft**  **W hite**  **1000 1**  **3 2**  **1 7**  **500 7**  **6.9**

5B.3 LINEAR GENERAL SERVICE FLUORESCENT LAMP OVERVIEW

**A linear**  **g eneral**  **service fluorescent**  **lamp commonly**  **consists of**  **a tube**  **containing**

**mercury (Hg)**  **along with**  **other gases**  **such as**  **argon. At**  **each end,**  **the lamp**  **contains an**  **electrode**

**made from**  **thin tungsten**  **wire. The**  **tube itself**  **is coated**  **with a**  **phosphor. During**  **operation of**  **the**

**lamp, electrons**  **flowing between**  **the electrodes**  **ionize the**  **mercury in**  **the lamp,**  **which produces** 

**ultraviolet photons**  **that the**  **phosphor converts**  **into visible**  **light. A**  **linear GSFL**  **in operation,** 

**i with**  **electrodes labeled,**  **is shown**  **in Figure**  **5B.1.**

Figure 5B.1: A Common Linear General Service Fluorescent Lamp in Operation

**5B­2 Several**  **physical and**  **operational characteristics**  **of a**  **fluorescent lamp**  **affect its**  **efficacy.**

**In particular,**  **longer length**  **lamps are**  **generally more**  **efficacious than**  **shorter length**  **lamps. This** 

**is because**  **the electrodes**  **of the**  **lamp use**  **energy but**  **do not**  **generate any**  **light. Longer**  **length**

**lamps have**  **more light­generating**  **length relative**  **to the**  **length of**  **the electrodes,**  **making higher** 

**efficacies possible.** 

5B.4 M ODEL FORMULATION, INPUTS, AND ANALYTICAL RESULTS

5B.4.1 2 8W 4­foot T5 Miniature Bipin (MiniBP) SO Halophosphor Baseline

**The m**  **odel that**  **DOE created**  **to relate**  **SO halophosphor**  **lamp efficacy**  **to other**  **factors**

**such as**  **end losses**  **is shown**  **below in**  **Eq. 5B.1:** 

⎛

α L ⎞

Lamp Efficacy

= K ⎜ ⎜ ⎟ ⎟ Eq. 5 B.1 ⎝ β L + C ⎠

**where** α **is the**  **amount of**  **light per**  **unit length**  **(in lumens**  **per inch),**  L **is the**  **lamp length**  **(in**

**inches),** β **is the**  **amount of**  **arc power**  **per unit**  **length (in**  **watts per**  **inch),** C **is the**  **wasted power** 

**due to**  **end losses**  **(in watts),**  **and** K **is a**  **scaling constant.**  **It is**  **assumed that**  C **is constant**  **as the** 

**length of**  **the lamp**  **varies.**

**Because t**  **he cool­white**  **halophosphor lamps**  **shown in**  **Table 5B.2.1**  **had a**  **slightly lower** 

**efficacy than**  **the other**  **lamps, DOE**  **chose to**  **use the**  **cool­white lamp**  **data in**  **Eq. 5B.1**  **to derive** 

**values for**  **the constants**  α

, β

, C

**, and**  K

**. This**  **allowed DOE**  **to create**  **model lamps**  **that reflected** 

**the possibility**  **of cool­white**  **lower­efficacy halophosphor**  **T5 lamps**  **entering the**  **US market.** 

**DOE performed**  **a statistical**  **assessment of**  **the cool­white**  **lamp data**  **in Table**  **5B.2.1 in**  **order to** 

**determine constant**  **values that**  **most accurately**  **represented the**  **observed efficacies**  **in the**  **table**

**for lamps**  **of different**  **lengths. These**  **values were**  **determined to**  **be:** α **= 2.176**  **lm in**  **­1**

**,** β

**=**

**­1 0.02017**  **W in ,**  C

**= 0.2478**  **W, and**  K

**= 23.03.** 

**The r**  **elationship between**  **lamp length**  **and efficacy**  **based on**  **Eq. 5B.1**  **and the**  **constant**

**values derived**  **above is**  **shown as**  **the black**  **line in**  **Figure 5B.2.**  **The cool­white**  **lamp data**  **from**

**Table 5B.2.1**  **is also**  **plotted in**  **the figure.**  **Based on**  **the model**  **and model**  **inputs above,**  **the**

**estimated efficacy**  **of a**  **nominal 4­foot**  **T5 cool­white**  **halophosphor lamp**  **is 86.0**  **lm/W. This** 

**efficacy would**  **be based**  **on initial**  **values after**  **100 hours**  **of seasoning.**  **To compute**  **the initial** 

**light output**  **of a**  **28W 4­foot**  **T5 cool­white**  **halophosphor lamp,**  **DOE multiplied**  **this efficacy**  **by**

**the ANSI**  **rated lamp**  **wattage. Note**  **that the**  **rated wattage**  **of a**  **T5 with**  **a nominal**  **wattage of** 

**28W is**  **27.8W. Using**  **this value,**  **DOE determined**  **the initial**  **light output**  **of the**  **28W**

**halophosphor T5**  **baseline lamp**  **to be**  **2,391 lumens.** 

**The e**  **fficacy of**  **the rare­earth**  **phosphor 28W**  **SO T5**  **lamp that**  **DOE analyzed**  **to**

**determine the**  **first efficacy**  **level (EL)**  **for the**  **4­foot T5**  **MiniBP SO**  **product class**  **is**

**approximately 20**  **percent higher**  **(at 103**  **lumens per**  **watt) than**  **the 28W**  **T5 halophosphor** 

**5B­3**85.9 **baseline. As**  **a comparison,**  **the average**  **efficacy of**  **the three**  **800 series**  **T8 lamps**  **that DOE** 

**analyzed in**  **the four­foot**  **MBP product**  **class is**  **approximately 20**  **percent higher**  **than the**  **average**

**efficacy of**  **the 34W**  **T12 halophosphor**  **lamps that**  **DOE analyzed**  **(92.8 lumens**  **per watt**  **vs. 77.9** 

**lumens per**  **watt). Thus,**  **DOE believes**  **that the**  **28W T5**  **halophosphor baseline**  **is representative** 

**of the**  **lower efficacies**  **that halophosphor**  **lamps achieve**  **in comparison**  **with efficacious**  **rare**

**earth phosphor**  **lamps.**

Cool White Halophosphor Preheat T5 Fluorescent Lamps

0 20 40 60 80 100 120

0 20 40 60 80 100

Lamp length (in)LampEfficacy(lm/w)

A

B

C

D

4ft estimate

Fit 86.0

Figure 5B.2: Lamp Efficacy Vs. Lamp Length For Cool White Halophosphor Preheat T5

Fluorescent Lamps

**Table 5**  **B.2 shows**  **properties of**  **the 4­foot**  **T5 MiniBP**  **SO lamps**  **that DOE**  **analyzed in** 

**this rulemaking,**  **including the**  **model 28W**  **T5 halophosphor**  **baseline lamp.**  **To determine**  **mean**

**light output**  **and lifetime**  **for the**  **halophosphor baseline**  **lamp, DOE**  **assessed the**  **lumen**

**depreciation characteristics**  **of halophosphors.**  **DOE found**  **that small**  **diameter halophosphor** 

**lamps can**  **have lumen**  **depreciations of**  **20 to**  **40 percent,**  **based on**  **a comparison**  **of initial**  **light**

**output and**  **mean light**  **output. DOE**  **chose the**  **midpoint of**  **this range,**  **30 percent,**  **to establish**  **the**

**mean light**  **output of**  **the 28W**  **T5 halophosphor**  **baseline lamp.** 

**5B­4**Table 5B.2: 4­foot T5 SO Lamps Analyzed

EL Lamp

D iameter Nominal

W attage Rated

W attage Rated

E fficacy Initial L ight

Output Mean L ight

Output Li fe C RI 2

W W lm/W lm lm hr

**B asel**  **ine/0 T**  **5 2**  **8 2**  **7.8 8**  **6.0 2**  **,391 1**  **,674 2**  **0,000 6**  **2**

**1 T5**  **2 8**  **2 7.8**  **1 04.3**  **2 ,900**  **2 ,660**  **2 0,000**  **8 5** 

**2 T5**  **2 8**  **2 7.8**  **1 09.7**  **3 ,050**  **2 ,898**  **2 0,000**  **8 5** 

**2 T5**  **2 6**  **2 6.0**  **1 11.5**  **2 ,900**  **2 ,660**  **2 5,000**  **8 5** 

5B.4.2 54W 4­foot T5 MiniBP HO Halophosphor Baseline

**The m**  **odel that**  **DOE developed**  **to determine**  **the efficacy**  **of a**  **28W T5**  **halophosphor**

**lamp was**  **based on**  **data for**  **short length**  **SO T5**  **halophosphor lamps.**  **HO lamps,**  **however, use** 

**different electrode**  **designs than**  **SO lamps**  **and also**  **have different**  **power densities.**  **DOE did**  **not**

**find any**  **lamps on**  **the market**  **that were**  **marketed as**  **HO T5**  **halophosphor. Because**  **of this,**  **DOE**

**instead established**  **the efficacy**  **of the**  **54W T5**  **HO halophosphor**  **baseline lamp**  **by using**  **the**

**efficacy difference**  **between the**  **EL1 rare­earth**  **phosphor 28W**  **T5 lamp**  **and the**  **28W T5** 

**halophosphor lamp.**  **As noted**  **above, the**  **rare­earth 28W**  **T5 lamp**  **at EL1**  **is approximately**  **20**

**percent more**  **efficacious than**  **the 28W**  **T5 halophosphor**  **baseline lamp.**  **DOE assumed**  **that the** 

**rare­earth phosphor**  **54W T5**  **HO lamp**  **at EL1**  **would also**  **be approximately**  **20 percent**  **more**

**efficacious than**  **a 54W**  **T5 HO**  **halophosphor lamp.**  **Based on**  **this difference**  **in efficacy,**  **DOE**

**developed a**  **model 54W**  **T5 halophosphor**  **baseline lamp**  **with an**  **efficacy of**  **76.6 lm/W.** 

**Table 5**  **B.3 shows**  **properties of**  **the T5**  **HO lamps**  **that DOE**  **analyzed for**  **this rulemaking,** 

**including the**  **54W T5**  **halophosphor baseline**  **lamp. As**  **done for**  **the 28W**  **T5 halophosphor** 

**baseline lamp,**  **DOE determined**  **the initial**  **light output**  **of the**  **54W HO**  **halophosphor baseline** 

**lamp based**  **on the**  **wattage and**  **efficacy and**  **then computed**  **the mean**  **light output**  **and lamp** 

**lifetime based**  **on halophosphor**  **lumen depreciation**  **characteristics. DOE**  **also selected**  **a 30** 

**percent lumen**  **depreciation to**  **determine these**  **properties for**  **the HO**  **baseline.**

Table 5 B.3: 4­foot T5 HO Lamps Analyzed

EL Lamp

D iameter Nominal

W attage Rated

W attage Rated

E fficacy Initial L ight

Output Mean L ight

Output Li fe C RI

W W lm/ W lm lm hr

**B asel**  **ine/0 T**  **5 5**  **4 5**  **3.8 7**  **6.6 4**  **,122 2**  **,885 2**  **0,000 6**  **2**

**1 T5**  **5 4**  **5 3.8**  **9 2.9**  **5 ,000**  **4 ,600**  **2 0,000**  **8 5** 

**1 T5**  **5 1**  **5 1.0**  **9 8.0**  **5 ,000**  **4 ,600**  **2 0,000**  **8 5** 

**C RI**  **is “Color**  **Rendering Index,”**  **a measure**  **of how**  **accurately a**  **lamp can**  **reproduce object**  **colors in**  **comparison**

**with daylight.**  **The value**  **of CRI**  **ranges from**  **0 to**  **100.**

**5B­5 2** **i** REFERENCES

**Rea, M**  **ark S.,**  **ed.** The IESNA Lighting Handbook: Reference & Application, 9th Edition

**. 2000.** 

**The Illuminating**  **Engineering Society**  **of America:**  **New York,**  **New York.** 

**5B­6**