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Covered Product Category: Fluorescent Luminaires

The Federal Energy Management Program (FEMP) provides acquisition guidance and Federal efficiency requirements for fluorescent luminaires. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

Meeting Energy Efficiency Requirements for Fluorescent Luminaires

Federal purchases must meet or exceed the minimum requirements listed in the following table. The minimum requirement metric is luminaire efficacy rating (LER), which is measured in lumens per watt (lm/W).

Table 1. Efficiency Requirements for Federal Purchases (LER in lm/W)
Luminaire Type
and Size
Optical Element Fluorescent Lamp Type
F28T5 F32T8 F54T5HO
Recessed,
1' x 4'
Lensed ≥ 69 ≥ 66 ≥ 55
Louvered ≥ 68 ≥ 62 ≥ 55
Othera ≥ 71 ≥ 68 ≥ 58
Recessed,
2' x 4'
Lensed ≥ 80 ≥ 81 ≥ 66
Louvered ≥ 64 ≥ 71 ≥ 60
Othera ≥ 75 ≥ 74 ≥ 65
  F14T5 F17T8 F32T8c F24T5HO
Recessed,
2' x 2'
Lensed ≥ 63 ≥ 59 ≥ 73 ≥ 57
Louvered ≥ 63
  F28T5 F32T8 F54T5HO
Surface Mount,
1' x 4'
Anyb ≥ 69 ≥ 72 ≥ 61
Surface Mount,
2' x 4'
Anyb N/Ad ≥ 74 N/Ad
Striplight,
1' x 4'
Anyb ≥ 76 ≥ 81 ≥ 71
a "Other" indicates a primary optical element other than a lens or louver, such as a perforated diffuser or a combination of optical elements (not including the reflector or housing).
b "Any" indicates any optical element.
c U-tube lamps
d "N/A" indicates too few models in the dataset to propose an efficacy rating (ER) for this lamp type.

 

Defining the Covered Product

The efficiency requirements in Table 1 apply to luminaires with linear fluorescent lamps used in commercial, industrial, or institutional buildings. Product performance must be measured in accordance with National Electrical Manufacturers Association (NEMA) Standard LE 5-2001, "Procedure for Determining Luminaire Efficacy Ratings for Fluorescent Luminaires," using IESNA LM-41, ANSI C82.2-2002 for fluorescent ballasts, and ANSI C78.81-2005 for fluorescent lamps.

Finding the Luminaire Efficacy Rating
LERs should be readily available in manufacturers' literature. If they are not, ask your supplier for LER values. If a LER is not available, buyers can calculate LER using this formula:

LER=(luminaire efficiency * total rated lamp lumens * ballast factor) divide by luminaire watts input

Luminaire efficiency (LE), total rated lamp lumens, ballast factor (BF), and luminaire watts input (input watts) may typically be found in manufacturers' product specification sheets and photometric reports.

Reducing Energy Costs: Save More Than $43 When You Buy Products that Exceed FEMP-Designated Efficiency Requirements

FEMP calculated1 that a recessed lensed 2-by-4-foot luminaire using three F32T8 lamps meeting the efficiency requirements saves money if priced $43 or less above the baseline model price. The most efficient available recessed lensed 2-by-4-foot luminaire using three F32T8 lamps saves money if priced $86 or less above the baseline model price. The estimated savings over the luminaire lifetime is $43 for luminaires meeting the FEMP-designated level and $86 for luminaires at the best available level. The complete cost effectiveness example and associated assumptions are provided in Table 2.

Table 2. Lifetime Savings for Efficient Fluorescent Luminaires
Performance Best Availablea FEMP-Designated
Efficiency Levelb
Less Efficientc
LER 98 (lm/W) 82 (lm/W) 70 (lm/W)
Power Input 83.6 Watts 83.7 watts 84.6 watts
Luminaire Light Outputd 8,162 6,879 5,998
Annual Energy Use 301 kWh 301 kWh 305 kWh
Adjusted Annual Energy Usee,f 221 kWh 263 kWh 305 kWh
Adjusted Annual Energy Cost $20 $24 $27
Adjusted Lifetime Energy Cost (15 years) $228 $271 $314
Lifetime Energy Cost Savings $86 $43
a The efficiency of the Best Available models was obtained during FEMP's market analysis and more efficient products may have been introduced to the market since this information was published.
b Federal purchases must be of products that meet or exceed FEMP-designated efficiency levels.
c The Less Efficient column represents low-efficiency fluorescent luminaires in this category.
d Luminaire light output = initial lamp lumens * number of lamps * ballast factor * luminaire efficiency.
e Annual adjusted energy use is adjusted by the ratio of FEMP-designated, or best available, luminaire light output to the light output of the less-efficient model. Annual energy cost and lifetime energy cost are also adjusted accordingly.
f Assumes that for FEMP-designated or best available luminaires, fewer luminaires or fewer numbers of lamps per luminaire can be used to provide equivalent light output to those of the less-efficient model.

 

Exceptions

Products meeting FEMP-designated efficiency requirements or ENERGY STAR® performance specifications may not be life cycle cost effective in certain low-use applications, such as when a device is being purchased for backup purposes and will remain in off mode for most of its useful life. For most other average or high-use applications, purchasers will find that energy-efficient products have the lowest life cycle cost.

Operating conditions vary from facility to facility. To help determine cost effectiveness for operating hours different from the example, multiply savings by this ratio:

Your annual hours of use divide by 3,600 hours of use

Complying with Contracting Requirements

Legislation and the Federal Acquisition Regulations (FAR) require Federal agencies to specify and buy ENERGY STAR-qualified products or, in categories not included in the ENERGY STAR program, products that meet or exceed FEMP-designated efficiency requirements. Agencies that follow requirements to buy efficient products can realize substantial operating cost savings and help prevent pollution. As the world's largest consumer, the Federal Government can help pull the entire U.S. market toward greater energy efficiency, while saving taxpayer dollars.

These requirements apply to all forms of procurement, including construction guide specifications and project specifications; renovation, repair, maintenance, and energy service contracts; lease agreements; acquisitions made using purchase cards; and solicitations for offers. Energy efficiency requirements should be included in both the evaluation criteria of solicitations and the evaluations of solicitation responses.

FAR Part 23.206 requires Federal agencies to insert the clause at FAR section 52.223-15 in solicitations and contracts that deliver, acquire, furnish, or specify energy-consuming products. FEMP recommends that agencies incorporate efficiency requirements into both the technical specification and evaluation sections of solicitations. Agencies may claim an exception to these requirements through a written finding that no ENERGY STAR-qualified or FEMP-designated product is available to meet the functional requirements, or that no such product is life cycle cost effective for the specific application. Additional information on Federal requirements is available.

Designing a Fluorescent Luminaire Installation: Special Considerations

Buyers are advised to compare LERs only within each luminaire category and sub-category, rather than choosing a luminaire for its LER value alone. Luminaire size, luminaire type, optical element, and lamp type may be selected for a variety of reasons based on the application—including color temperature, color rendition, light output, light distribution, rated lifetime, and cost.

Target efficacy rating (TER) is another metric that is informative in comparing luminaire effectiveness in delivering light to the application target. While LER uses luminaire efficiency (LE, percentage of total lamp lumens that leaves the luminaire), TER uses energy effectiveness factor (EEF, the percentage of total lamp lumens that reaches the specified target area typical of the luminaire) in its calculation of luminaire efficacy. Since TER is available in some but not all manufacturer literature, this guidance relies on LER as its efficiency metric. However, buyers wishing to understand TER may download NEMA Standard LE 6-2009, "Procedure for Determining Target Efficacy Ratings for Commercial, Industrial, and Residential Luminaires."

Buyer Tips: Choosing Efficient Fluorescent Luminaires

When purchasing fluorescent luminaires, specify or select models that meet the efficiency requirements shown above. The Federal supply sources for energy-efficient fluorescent luminaires are the Defense Logistics Agency (DLA) and the U.S. General Services Administration (GSA). GSA offers them on Schedule 62-II, as well as through its online shopping network, GSA Advantage!

User Tips: Using Products More Efficiently

In addition to selecting the optimal fluorescent luminaire for the application, building operators should endeavor to operate lighting only when needed. The use of lighting controls such as occupancy sensors, task tuning, and dimming when daylight is present (where applicable) should be considered to facilitate further energy savings.

Finding More Information

Lawrence Berkeley National Laboratory provided supporting analysis for this product overview.

Updated November 2012

1Based on the following assumptions: Assumes the fluorescent luminaire is a recessed lensed 2-by-4-foot luminaire using three F32T8 lamps and is used an average of 3,600 hours per year for 15 years, which is typical for Federal facilities.

Annual energy use is based on NEMA's LE 5. The electricity rate is $0.09 per kWh, the average at U.S. Federal facilities. Future electricity price trends and a 3% discount rate are based on Federal guidelines (NISTIR 85-3273-26) and are from the Annual Supplement to NIST Handbook 135 and NBS Special Publication 709, Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis-2011.