The U.S. Department of Energy (DOE) has issued new energy standards for general-service fluorescent lamps that are expected to reduce availability of standard 4-ft. linear and 2-ft. U-bend 32W T8 lamps as well as some reduced-wattage T8 lamps. The rules go into effect January 26, 2018. After that date, distributors may continue to sell their inventories of non-compliant lamps until these are exhausted.
DOE estimates consumer cost savings with a cumulative net present value (including both energy cost savings and increased initial cost) of between $2 (7% discount rate) and $5.5 billion (3.3% discount rate) over the next 30 years.
Previous regulations, which took effect in July 2012, eliminated a majority of 4-ft. linear and 2-ft. U-bend T12 lamps and many 8-ft. T12 and T12HO lamps. Low-color-rendering (70-79 CRI) T8 lamps also failed to comply, but several manufacturers gained a temporary exception for their specific products, which expired in July 2014.
The new rules strengthen existing energy standards (minimum source efficacy in lumens/W) by 1-4% for 4-ft. linear T8 and 2-ft. U-bend T8 lamps, approaching the maximum technology level. Lamps that do not comply are prohibited from manufacture and importing as of the effective date. The rules also strengthened energy standards by 7-10+% for 4-ft. linear T5 and T5HO lamps while expanding covered wattages. Energy standards for 8-ft. lamps were not changed.
Previous exceptions still apply, including 1) lamps designed to promote plant growth, 2) lamps designed specifically for cold-temperature applications, 3) colored lamps, 4) impact-resistant lamps, 5), reflectorized or aperture lamps, 6) lamps designed for reprographic applications, 7) UV lamps, and 8) lamps with a CRI of 87 or higher.
Over the next three years, manufacturers will review their products and reengineer or discontinue them on a case-by-case basis. Interviews with lamp manufacturers suggest likely outcomes. In the T8 category, a majority of lamps pass the standards. However, these are primarily reduced-wattage (e.g., 25W, 28W) lamps. Today’s basic-grade 32W lamps do not comply. Some standard 32W T8 lamps may be reengineered, but overall, availability will be reduced. Extended-life lamps will continue to be available but may be limited to wattages lower than 32W.
The T5 category does not appear to be adversely affected. Manufacturers stated that today’s 4-ft. T5 and T5HO lamps will satisfy the new rules with little or no reengineering.
The net effect is consumers are likely to have fewer T8 lamps to choose from, with surviving options presenting a higher average initial cost. Consumers will have two compliance options that save energy. They can switch from full- to reduced-wattage lamps, or they can operate compliant lamps on a dimming ballast and control. DOE estimates an average payback of 3-4 years for switching from full- to reduced-wattage lamps.
If the existing installation contains continuous-dimming ballasts, owners will need to determine that these ballasts are rated for reduced-wattage lamps. This information is on the ballast label. Operating reduced-wattage lamps on dimming ballasts not rated for them will produce unsatisfactory performance. If the existing dimming ballasts are not rated for reduced-wattage lamps, the owner will need to replace the existing lamp with a compliant full-wattage lamp or replace the dimming ballast with one rated for reduced-wattage lamps.
Lighting practitioners should advise their customers about the new regulations and the benefits of a lighting upgrade. They should consult with manufacturers to confirm availability of compliant alternatives.
Owners should consider the benefits of an upgrade compared to replacing non-compliant lamps individually as part of maintenance. Replacing all lamps at once ensures consistent lighting quality, reduces the risk of matching incompatible components, and provides an opportunity to completely re-evaluate the existing lighting system.
DOE’s 2010 National Lighting Inventory estimated that 20% of all lamps in the commercial building sector and 44% in the industrial sector are 4-ft. T8. In 2010, DOE estimated that there were 532 million 4-ft. linear T8 lamps and 14 million T8 U-bend lamps installed in commercial and industrial buildings in the United States.