a.The
new Lumens rating makes buying LED bulbs much simpler
Choosing a
light bulb today is more complicated than ever, and the choice of bulbs keeps
growing. Consumers have to choose between incandescents, CFLs, halogens and
LEDs, and a multitude of sizes and shapes, different bases, and of course
widely differing prices.
The FTC has recently mandated that, by 2012, all
light bulb packages will be standardized with new labels which will make it
much easier to buy light bulbs, whether they be incandescent, LED, CFL or
halogen. The main indicator on the light bulb package will be “lumens”, which
will replace the current “watts”. Lumens represents the amount of light emitted
by a light source, and is a more accurate measure of the brightness of a bulb.
Incandescent
Watts
|
CFL Watts
|
LED Watts
|
Lumens
(Brightness)
|
40
60 75 – 100 100 150 |
8 – 12
13 – 18 18 – 22 23 – 30 30 – 55 |
4 – 5
6 – 8 9 – 13 16 – 20 25 – 28 |
450
890 1210 1750 2780 |
So no matter
what kind of bulb you are interested in, simply comparing lumens will enable
you to compare the brightness level each bulb will deliver. After you determine
the lumen level you prefer, you can then look to other indicators such as
energy efficiency, lifetime run cost, and dimmability to select the ideal bulb
for your application.
To learn more about the upcoming new labelling
system for all light bulbs, see our article: Lumens are the New Watts.
b.
LED bulbs contain no mercury
One of the
hurdles to broad consumer acceptance of energy-efficient CFL bulbs is the
presence of a small amount of mercury in the bulbs. Consumers are concerned
that they may be adding mercury to the environment when the bulb is disposed.
If a CFL bulb is broken, consumers are advised to treat the broken bulb as a
hazardous material.
The mercury
issue with CFLs is confusing because manufacturers reason that actually less
mercury enters the environment when CFLs are used to replace incandescent
bulbs. A power plant will emit 10mg of mercury to produce the electricity to
run an incandescent bulb compared to only 2.4mg of mercury to run a CFL for the
same time. The net benefit of using the more energy efficient lamp is positive,
and this is especially true if the mercury in the fluorescent lamp is kept out
of the waste stream when the lamp expires. However, this reasoning only applies
if your electricity comes from coal-fired sources.
The presence
of mercury in CFL bulbs is a real issue with consumers. At Eartheasy’s online
store, we have discontinued selling CFLs because of customer concern over the
presence of mercury in CFL bulbs.
LED bulbs
contain no mercury, so there is no special concern with handling or disposal of
LED bulbs.
c.
LEDs give instant light, and many LED bulbs are dimmable
When turning
on CFLs and tubular fluorescent light bulbs, there is a slight hesitation
before brightness is achieved, and some bulbs may flicker during warm up or
even during operation. Unlike fluorescents, LED bulbs, like incandescent bulbs,
reach full illumination as soon as they are turned on. This is a real advantage
over CFL bulbs in areas of the home where lights are frequently turned on and
off. Also, LED lights produce a steady light which does not flicker.
Earlier
versions of LED bulbs had the disadvantage of not being dimmable. Today, many
LED bulbs are designed to work in dimmable switches which are provided in many
lamps and home lighting fixtures. Just be sure to check the package to ensure
the bulb you have selected is dimmable.
LED lights
last a long time and unlike other light bulbs, they do not burn out, but rather
dim over time.
d.
LEDs won’t contribute to heat buildup in your home
This summer
has been the hottest on record, and homeowners are increasingly interested in
measures which can help reduce the amount of heat generated within the home.
Electric lighting is one of the main culprits. Incandescent lights produce
ideal illumination in terms of brightness and quality of light, but they also
produce a considerable amount of heat.
A 100 watt
incandescent bulb produces 100 watts of power. From an energy point of view, it
puts out 100 Joules of energy per second. In a small closed room, 4 m (12ft) x
4 m(12ft) x 3 m(9ft) or 48 m³ with a single 100w bulb:
48 m³ x 1.2
kg/m³ = 58 kg of air
100J = 1000 J/kgC x ∆T x 58 kg
∆T = 0.0017 deg C, change in temp. per second
100J = 1000 J/kgC x ∆T x 58 kg
∆T = 0.0017 deg C, change in temp. per second
In one hour,
the bulb would produce a 6 degree C rise. or 11 deg F. This assumes the room is
closed to ventilation, so the temperature would be lower if the room were ventilated,
or larger. But it serves to illustrate that the heat contribution from an
incandescent bulb is significant.
LED bulbs,
by contrast, remain cool. High power LEDs are designed with heat sinks, usually
aluminum struts around the lower bulb, which keeps operating temperatures low.
LED bulbs do not contribute to heat buildup in a room.
e.
Insects are not attracted to UV-free LED bulbs
Many LED
bulbs (but not all) do not give off ultraviolet light, which is known to
attract flying insects. Check the package label for UV information if you are
interested in this feature.
There are
also specialty LED bulbs which have yellow lenses or bulbs, which are designed
for outdoor use in carports, decks or on patios. These yellow bulbs will not
attract the bugs and moths which seem to cluster around ordinary white bulbs.
These bulbs produce adequate light for the intended area; they just don’t attract
bugs.
f.
Choose LED bulbs which are UL Listed, not UL Compliant
A light bulb
package marked “UL Compliant” is no assurance that the LED bulb has been tested
or approved by the Underwriters Laboratory. It only means that the manufacturer
has followed recommended UL guidelines in production and technical aspects.
A“UL Listed” LED bulb has passed stringent tests put forth by UL, and consumers
are advised to look for the UL Listed mark.
In the race to garner a share of the emerging LED
market, manufacturers may use the UL Compliant mark to help sell more light
bulbs, but this is no guarantee of bulb quality. Consumers should be wary of
new LED bulbs which are priced very low, are sourced from unknown suppliers, or
have unrealistic product claims.