ILE statement on CFL replacement of GLS lamps

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					ILE Statement on the Replacement of GLS
Lamps with Energy Efficient Light Sources
The Government is currently seeking to reduce carbon emissions by
looking at the efficiency of different energy consuming products.
The current proposals review eleven different areas, including
domestic, commercial, and street lighting. A major part of the
proposals for reducing the use of electrical energy for domestic
lighting involves the replacement of the traditional shaped GLS lamp
(commonly referred to as a bulb) with energy saving alternatives
such as the compact fluorescent lamp (CFL) which provide energy
savings of around 80% or energy saving tungsten halogen lamps
which can save between 20% and 50% in energy use. This
statement examines the benefits and disadvantages of this proposal
and is limited to lamps designed to be a direct plug-in replacement
for existing traditional shaped GLS lamps.         The use of these
alternatives provides a simple and easy means by which we can all
help to reduce our carbon footprint and help to protect the world.

Do CFLs provide the same level of lighting as GLS lamps?
Most GLS lamps provide approximately 11 to 13 lumens of light per
watt of energy consumed -- so a 60W clear or pearl GLS lamp
produces approximately 700 lumens (softone lamps produce 600
lumens) of light and a 100W GLS lamp produces approximately
1,300 lumens (softone lamps produce 1,200 lumens). In
comparison an 11W CFL, with their softone appearance, produces
approximately 600 lumens and a 20W CFL produces approximately
1,200 lumens. The comparison with a softone lamp is accepted by
Trading Standards and must be marked on the packaging. As with
GLS lamps, CFLs age, and their light output falls so that by the time
they have burnt half their life, their output will be considerably
lower at about 80% of their initial output. This reduction in light
output will continue as the lamp ages and should therefore be
considered when deciding which wattage and output CFL to use.

Do CFLs provide the same quality of light as the GLS lamp?
A GLS lamp has a correlated colour temperature (CCT) of 2,800K
and a colour rendering index (CRI) of 100. The higher the colour
temperature, the colder the appearance of the light produced. The
closer the CRI is to 100, the better the colour rendering of the light
source. The GLS lamp therefore has a warm CCT and very good
colour rendering properties. While CFLs come in a number of colour
temperatures, those generally used in domestic situations are
classified as Warm White with a CCT of 2,700K and a CRI of 82. In
this example the colour temperature is very similar to that of the
GLS lamp and little difference will be noticed. However, as the GLS
lamp has a better CRI, it will reproduce most colours accurately,
whereas a CFL will distort some colours due to the non-continuous
wavelengths of the light produced. Where colour rendering is of
importance energy saving tungsten halogen alternatives may be

Another light quality issue concerns the size of a CFL lamp. As the
filament of a GLS lamp (with a clear glass envelope) is quite small,
it produces relative strong shadowing, interesting areas of light and
shade in the interior and a degree of visual ‘sparkle’. However, as
the CFL lamp is quite a large light source, by comparison, it
produces no distinct shadows and creates rather a flat, bland
lighting effect which many people find visually unsatisfactory.
Where distinct shadows and visual sparkle are of importance energy
saving tungsten halogen alternatives may be used.
Do CFLs use less energy?
A GLS lamp will use approximately six times the energy of an
equivalent CF. Therefore a CFL shows a considerable reduction in
the energy consumed and metered at the domestic premises.
Domestic CFLs have a low power factor and thus a higher lamp
current which will result in higher losses in the power distribution system but
energy savings are still achieved. This effect does not affect energy saving
tungsten halogen lamps. The Government are appointing independent experts to
evaluate the true energy savings to be gained from converting to CFLs and other
energy efficient light sources. The electronic circuitry in CFLs can also
cause high levels of distortion to the electricity supply which may
have adverse effects on other electrical equipment. Fortunately the
electrical load from CFLs in a domestic situation is small in
comparison to the remainder of the electrical load, so these effects
are substantially reduced and should not cause problems. In
installations with large quantities of CFLs it is possible that this
distortion may affect other equipment and care may be needed but
no practical problems have been experienced in such installations.

Do CFLs take a long time to reach full brightness?
GLS lamps provide almost instantaneous light when switched on
whereas CFLs do not start instantaneously and require a short time
to strike – they also take even longer to run up to their full light
output (the current estimated starting time is that they reach 60%
of their rated light output in one minute). This delay may cause
problems in some domestic installations where light is required
instantly, for example on stairs in the middle of the night or in
cupboards or storage areas, where the user is looking for something
in a hurry. It is obviously unsatisfactory to have to wait for the light
to switch on and run up to full brightness. Where a long wait for run
up to full brightness is not acceptable energy saving tungsten
halogen alternatives which have an instantaneous run up may be

Are CFLs financially subsidised?
Many CFLs are subsidised by the electricity companies to help
reduce the need to invest in new generating, transmission and
distribution systems; similarly, other environmentally aware
organisations also subsidise these lamps to help protect the
environment. Both strategies are to be welcomed and applauded –
but will these subsidies remain once a high percentage of users
have committed themselves to the use of CFLs, and the GLS
alternative is no longer in production?

Do CFLs have any adverse health risks?
A number of organisations dealing with specific medical conditions
have concerns over the quality and consistency of the light output
from CFLs. The majority of these complaints are concerned with:
   •   The quality of the light (i.e. the colour rendering and the
       colour reproduction of the light) both of which can be varied
       in production to suit different requirements, albeit at a cost.
   •   The effect of ‘flicker’ in the light output -- a long-standing
       criticism of fluorescent and discharge lamps. In fact, this has
       potentially been overcome by the use of high frequency
       control gear, which moves the frequency of ‘flicker’ to well
       above the limits normally considered a problem to the human
       visual system.
   •   The intensity of the light – CFLs, especially the exposed
       tube type, have a higher surface brightness than comparable
       output GLS lamps. However, this can be offset to a large
       extent by the use of lamps with an external outer frosted
       envelope, which gives the lamp an appearance similar to
       conventional GLS lamps.

Do CFLs last longer?
GLS lamps have an average rated life of 1,000 hours compared to
the average rated life of a CFL of 8,000 hours. A light in one of the
principal family rooms, such as a living room or kitchen, will be
used for approximately 1,000 to 2,000 hours per annum. Frequent
switching on and off of a CFL will reduce its life and it is
recommended that CFLs should always be run for a minimum of 15
minutes each time they are switched on, to minimise the effect of
switching on the lamp life.

Are CFLs more economic?
Approximately 90% of the energy consumed by a GLS lamp is
produced as heat which is often classified as ‘waste’ heat (i.e. 55W
of the energy consumed by a 60W GLS lamp or 90W of the energy
consumed by a 100W GLS lamp is produced as heat not light. In an
average UK domestic property this heat will actually contribute to
the heating of the surrounding room and technically reducing the
amount of heating required. However the actual effect of this additional
heat will vary dependent upon the location of the lamp and the type of control
systems used on the heating system. This heat may be a nuisance on
very hot summer’s nights or where the property is so well insulated
that it needs air conditioning to maintain a comfortable
temperature. In most other domestic situations, the heat from GLS
lamps may not be wasted and may help to offset the heating
supplied by the central heating system.

Are there any disposal problems with CFLs?
Modern GLS lamps can safely be recycled or disposed of as there
are very few dangerous materials used in their manufacture. Older
GLS lamps used lead in the solder but this has now been replaced
with other materials. CFLs do use small amounts of potentially
dangerous materials in their manufacture, such as mercury.
Although the mercury content is about the size of a pin head, with
the massively increased use of CFLs across the country, there will
be an increase in mercury into landfill following disposal of the
lamps. This would not occur if CFLs were disposed of by recycling to
recover the mercury, phosphors, and other materials used in their
manufacture. Unfortunately, while it is a requirement of the WEEE
Regulations to recycle lamps, discarded GLS and CFL lamps placed
in domestic waste will not be recycled but generally disposed of into
landfill. . This increase in mercury due to disposal is more than
offset by the reductions of mercury that would have been emitted
from fossil fuels burnt by power stations supplying the extra power
for GLS lamps.

The consumer should have no problems from the disposal of old
lamps provided they are not broken. Where CFLs are broken there
is a very small possibility of ingesting the phosphors and mercury
but this can be minimised by sensible precautions, such as not
breathing in any of the powders from the broken lamp. Care should
be taken when dealing with either a broken GLS lamp or CFL not to
cut oneself on the glass or resulting sharp edges.

Will CFLs fit my existing light fittings?
Many CFLs are larger than comparable GLS lamps and therefore
may not be able to fit into fully enclosed light fittings -- or may
protrude out of the light fitting, as can be seen in many retro-fit
installations. However, manufacturers are taking account of this, so
CFLs are shrinking in size, and new shapes of lamps are available
which mimic existing GLS lamps, as well as candle lamps and golf
ball lamps. Unfortunately such lamps generally are only available at
the full retail price, making them expensive in comparison with GLS
lamps and are often only available in a single wattage.
Can CFLs be dimmed?
GLS lamps can be varied in output from 0 to 100% using simple
voltage reduction devices in place of the wall switch. This high
degree of variability allows the level of lighting for the specific task
to be readily set, or the ambience of the room to be varied and
changed to suit the mood of the occupants. The level of light
produced by a GLS lamp is roughly proportionate to the energy
consumed and paid for. CFLs cannot be readily varied and need to
have specialist control units fitted or need to be of a special design.
The year 2007 also saw the limited introduction of new CFLs by
such companies as Varil-Lite and Megaman, which can be dimmed
on conventional rotary dimmers.

However, the energy consumption of a CFL when dimmed down is
not always in direct proportion to the energy consumed -- for
instance when varied down to 50% light output the energy
consumption could be approximately 60% of the rated consumption
or even higher. So you will be paying more for each lumen of light

Can I use CFLs with electronic timers or electronic sensors?
Many of us have got used to having lights on electronic sensors or
time switches to switch on or off at pre-determined times, or to
specific lighting levels, to detect intruders. Unfortunately many of
these control systems are not compatible with standard CFLs and
may be destroyed by the switch on current from the lamp. As the
sales of CFLs increases, suitable equipment is becoming available --
but care should still be taken to ensure that permanent damage, or
fire, cannot be caused by retro-fitting CFLs in GLS lighting systems
controlled by electronic equipment.

The effect of age on lamp characteristics
GLS lamps tend to fail just before the reduction in light output
through life is noticeable. As CFLs approach old age their light
output drops significantly, the run-up time to full output becomes
extended and the presence of flicker becomes more noticeable,
however, newer types of CFLs do not suffer from flicker. Were
flicker is a problem energy saving tungsten halogen alternatives up
may be used.

Are there any other energy-efficient replacements for GLS
The pressure to reduce energy consumption has increased the
development of alternative light sources. It is anticipated that within
two to three years alternative light sources, such as LEDs, will be
available to replace GLS lamps. Some of these lamps may have
advantages over the CFLs currently available – however, the rapid
development, and improvement, of CFLs will continue to reduce
many of the adverse features of these types of lamp.