Lighting
Lighting problems and solutions in Carbon Cops
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Downlights and guards and ornamental lights at the Lanes
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Appropriate choices of energy efficient lighting at the Barries
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LED dynamo torch and lighting changes at the Renters
Incandescent lights and replacements
Incandescent lights are very inefficient – most of the electricity they use is converted to heat, not
light. Australia has plans to phase out all incandescent lightbulbs other than those that are required
for specialty purposes.
There are many replacements that typically use a fifth or less of the power of the equivalent
incandescent. The most well known are the common compact fluorescents or CFLs, but there are also
microfluoros, CFL spotlights, LEDs, high-efficiency fluoro tubes and even high-efficiency halogens.
Fluorescent tubes have a coating of phosphor on the inside. That phosphor absorbs energy and
re-releases it as light. The colour of the phosphor affects the colour of the light produced. CFLs are
commonly available in two “temperatures” – “daylight” or “cold white” at 6500K, and “warm white”
at 2700K. 6500K gives a harsher, bluish light, and 2700K gives a softer and warmer colour light
more like incandescent bulbs. Because they convert so much less of their energy to heat, CFLs
save you money – both in the lights themselves, but also by needing less air conditioning in lit areas.
As well as the familiar light bulb replacements, CFLs are available in a range of shapes and styles.
They come in super-short (for small lamps), small spirals, enclosed in pearlescent spherical globes,
enclosed in pearlescent “leaf” shapes for candelabras, and as microfluoros inside halogen-like
cases. They even come as outdoor spotlights.
To ensure that CFLs would be suitable for the home market, the technology’s improved notably in
the last decade or more. The flicker’s been cut down significantly, and colour choices have become
available. And dimmable CFLs are now available from specialist outlets. CFLs still have a short
come-on time rather than an instant start, slowly increasing to full brightness over the first couple of
minutes. This extends the life of the bulb and is one reason why they have so much longer lifespans
than incandescent bulbs.
LEDs are another increasingly common form of lighting. They have an extremely low power draw,
and are now available in a wide range of brightnesses and colours, including blue and white. They
come in a range of forms suitable for replacing standard lighting, including a halogen-like bulb.
They’re also becoming more common as fairy lights or Christmas lights, because of their low power
consumption. One public place where LEDs can be seen in action is along the St Kilda foreshore in
Victoria, where the streetlights are no longer yellow sodium bulbs, but sets of similar-coloured LEDs.
290 streetlights were changed over, cutting the carbon emissions from those streetlights by 80%.
Halogen lights and replacements
Halogen lights consume more energy than many home owners realise. While they are low voltage,
they are not low power. Normal halogens use 50W of power, and they also use another 10W or
so in their transformer for a total of around 60W. Common incandescent light bulbs also use 60W
of power.
Halogen lights’ narrow beam spread makes them very effective at providing feature lighting. This
is also the feature that makes them ineffective as general room lighting – they need to be installed
in banks in order to get sufficient light coverage of an area. Because each light is using 60W,
as soon as you have two or more halogen lights they are consuming more power than even the
| | Carbon Cops : Lighting
brightest of normal incandescent bulbs. If you need six halogen lights to replace the effective
light of one incandescent bulb in a room, it costs you between three and six times as much to
run your lights.
Unfortunately, dimming the halogens doesn’t help as much as it seems. A bulb’s light output
to energy use isn’t linear, so when it’s at 50% of the brightness it’s still using 80% of the
power. If you always keep your halogens dim, consider getting the next brightness down
rather than a bright one and dimming it.
There are several lower-energy replacements for standard halogens, including miniature
compact fluorescents that only draw 9W, and LEDs that draw just 3W. There are also highefficiency halogens that draw 35W for the same light output as a normal halogen.
Downlights and downlight guards
Halogen downlights are high energy users – and a lot of that energy is converted to heat in
the light and in each light’s individual transformer. Because this is a fire risk, insulation and
other non-fireproof items need to be a minimum distance from any recessed downlight by
Australian standard. The recommended clearance around low-voltage halogens is 90mm.
This means that even a thickly insulated ceiling can have large holes in the insulation around
the downlights. And downlights are often installed in banks, as their low-angle-of-spread
means you need several of them to make a bigger space feel well-lit. So a house lit with
halogens may have insulation that’s far less than 100% effective at trapping heat.
Downlight guards are one solution to this problem. They seal against air so that it can’t leak
through the light fitting from the warm room below, stopping draughts and loss of alreadyheated air. And because they’re fireproof, they allow insulation to be packed up against them,
creating a full covering with no holes. Both of these measures cut down the energy it takes to
heat a room, because they keep the heat from leaving.
n Arrowform and Isolite
www.isolite.com.au
n Exfoliators passive fire protection products
www.exfoliators.com.au/PFP.html
Dynamo LED torch and alternative lighting
In the future we may face restricted electricity supply, where only a small amount of
electricity can come to each house at any one time. Our lighting needs to be adapted to
those conditions.
Each light in the Renters’ house was changed to an energy efficient bulb, primarily compact
fluorescents which are the best suited for standard lamps. The fluorescent tubes in their
ceiling lights were also changed to a more energy-efficient type.
For the times of no electricity, the students were given a torch – but one that doesn’t use
normal batteries. It runs on a dynamo, where energy from motion is converted into electrical
energy, and there’s a special rechargeable battery inside to collect that energy. To charge the
battery, you wind the torch up. This torch will never need its batteries changed, and never
need to take electricity from the grid.
Torches operating on this principle are available from science and environment shops and
hardware stores, around the country and online.
© ABC Copyright 2007
| | Carbon Cops : Lighting