Green Collar Careers - Lighting
Low cost incandescent bulbs were a revolutionary product that
over 100 years later hasnít changed much. Nearly 90% of the energy
required to light an incandescent bulb is turned into heat rather then
light so they will add significantly to the load on the air
conditioner during the summer season. Heat generated from an
incandescent costs more then twice as much as the heat from a heat
pump so its not a very cost effective heater. The only positive point
about an incandescent bulb is they are the least expensive to
Halogen lighting is slightly more efficient then an
incandescent by about 15%. From practical experience they have about
the same life as an incandescent.
Compact Florescent Lights (CFL) require ľ the power for
the same amount of light from an incandescent. Not all standard
fixtures can accept a CFL although generally at least 80% of the
fixtures in a typical home can. CFLís do not work as well in colder
climates so they may not be very good for outdoor lighting. CFLís
generally cost about 4 times that of an incandescent which is probably
the main reason most people still use incandescent lights. Most CFL
manufacturers may claim 10 times the life over an incandescent, but
thatís only in specific laboratory conditions designed to optimize the
life of the CFL. In practical application, 4-5 times the life is more
realistic making the CFL cost effective based on replacement cost
alone. The one drawback to CFL's is they don't work very well on
dimmer circuits. When installed on a dimmer equipped circuit
they may take a few seconds to "fire up" even with the switch turned
up all the way.
Standard Florescent Tube (SFT) fixtures are still the most cost
effective of the lighting methods however they require special
fixtures and lack the aesthetic appeal for most homeowners. Thatís why
they are mostly only used in garages and utility rooms. SFTís also are
prone to a flicker that some people find annoying. This flicker has
been resolved with CFL and some of the higher priced SFTís.
Light Emitting Diode (LED) technology will be the next
generation of lighting but isnít yet ready for cost effective use.
LEDís are about 95% efficient, with nearly all the losses in the
voltage conversion circuits that are self contained. The LEDís
themselves will last 20+ years, however the voltage conversion
circuits will only have a life of about 10 years at this point. More
of a novelty then practical, its expected that cost effective versions
will be available within 5 years.
Understanding the different lighting options it should be clear that
the CFL offers the best solution at this time. If the homeowner is
using exclusively incandescent lighting, the following gives a typical
savings potential in a moderate climate by switching to CFL.
Energy reduction for CFL vrs Incandescent:
70% reduction for lighting energy + 10% reduction for heating energy =
Applied to 80% of the home light fixtures; 80% * 80% = 64%
Average portion of power consumed for lighting from
Chart 202 =
Reduction of power consumed for lighting; 8.8 * .64 = 5.6%
CFL lighting also provides a sales and installation opportunity for the
Home Energy Auditor. Keeping a range of bulbs in your inventory
and a ladder for installing them can be profitable.
LED's seem to
offer an appealing attraction to the gadget-conscious. It would
be worthwhile to have a few LED spotlight bulbs. LED's "shine"
in fixtures that are high up and shine down as these are the most
difficult bulbs to replace and the ultra long life of an LED will last
for up to 20 years.