Retrotec USACE - Manual (Page 228)

D98 ENERGY & PROCESS ASSESSMENT PROTOCOL
lamps because they offer no advantages over other alternatives and suffer from
rapid lumen depreciation and poor color rendering.
Figure D155. Mercury vapor lamps should be
replaced with more effi cient light sources.
For industrial and outdoor lighting fi xtures and industrial applications, re-
place mercury vapor lamps with metal halide lamps. There are a number of
metal halide lamps that are designed to operate with mercury vapor ballasts,
but these are not the most energy-effi cient sources. For optimal performance,
choose pulse start ceramic metal halide lamps with electronic ballasts when-
ever possible (but note that they are not available in all wattages).
Replace mercury vapor downlights with compact fl uorescent or low-watt-
age metal halide downlights to get better energy effi ciency, lumen mainte-
nance, and color qualities.
Since the mercury vapor lamps are being taken off the market by the lamp
manufacturers, it is a good idea to replace these with more effi cient sources
now rather than wait until the lamps burn out and be without an immediate
replacement at what may be a critical time, leading to the dangerous situation
of having areas without lighting at all.
D.5.14 Using Non-LED Exit Signs (Ineffi ciency)
LED (light-emitting diode) technology is new technology for lighting that is
fi nding increasing use in commercial applications. Examples are traffi c lights,
vehicle lights, and exits signs in buildings (Figure D156). LEDs are only now
beginning to be considered for offi ce lighting, because it is quite diffi cult to
make a white LED; the applications above, including exit signs, are not re-
quired to be white in color. LED exit signs are now standard technology, just
like T8 and electronic ballasts. Exit signs are typically required by code to be
on 24 hrs/day, 7 days/wk, so any energy savings adds up. A typical LED exit
sign consumes 2–4 W while a non-LED sign can consume as much as 40 W—a
10-fold difference. At $0.15 per kWh, that is $50 a year saved per exit sign. In a
large commercial building with dozens of exit signs, the savings can be several
thousand dollars annually.