Tip:
Highlight text to annotate it
X
Energy Efficient Lighting – Solutions for Offices
Independent research suggests about 40% of all the energy consumed in buildings is used
for lighting. So, if you want to reduce the electricity consumption in your office and
switch to energy efficient lighting what options do you have? Well energy efficient lighting
is a combination of the following 6 factors. Firstly the lamp or the light source itself.
You should use a lamp which provides the highest level of light for the lowest level of electricity
consumption, we call this the lumen per watt ratio. This efficiency ratio should also be
maintained during the lifetime of the lamp, this is known as lumen maintenance. It’s
also important to have the right amount of light. The quality of the light should also
fit the application, for example in offices Philips recommends a colour rendering of above
80. The second relevant factor is the ballast, switching from traditional electro magnetic
ballasts to new electronic ballasts will save up to 25%. The third factor is the use of
lighting controls. These are simple devices which turn off or dim down the lighting when
people are no longer present, saving up to 30%. Other controls can dim the light when
enough natural daylight is present, which offers additional energy savings of up to
30%. The fourth factor is the luminaire or more specifically the optics. The light output
ratio indicates how energy efficient a luminaire is for example by switching from traditional
cover luminaires to state of the art lumella luminaires you can save more than 50%. In
addition the optics should direct the light to the places where it is needed and avoid
glare, for example in office lighting a delta shaped beam in preferred. The fifth factor
is the lighting design. This design should be based on the right lighting level, not
too high, not too low. The lighting should be uniform to avoid dark spots and take into
account the colour of the walls and carpets. In fact a poor lighting design can use up
to twice as much energy as a good one. The sixth and final factor is usage and maintenance,
for example the group replacement of lamps should be done and the luminaires themselves
should be cleaned regularly and switch off the lighting when it’s not needed.
So given these six factors what are your options for switching to energy efficient lighting?
The first thing to do is to conduct an audit of your current installed lighting. You could
do this yourself or hire an external consultancy but the key thing is to understand your base
line and potential for savings. This audit should result in a figure for the watts actually
used by the installed lighting per square meter in your office. If this figure is more
than 30 watts per square meter, which is common in traditional offices you have very inefficient
lighting and hence plenty of opportunity to save energy. Between 15 and 30 watts per square
meter you have a lot of interesting options for saving energy, whilst between 8 to 15
watts per square meter you still have options for example by using lighting controls. Less
than 8 watts per square meter means your lighting is already energy efficient by today’s standards.
Ok, now lets assume that you have done this exercise and you know there is a lot of potential
for energy savings, you have three main options. First is a full renovation, combining all
6 of the factors just mentioned, second is a one to one luminaire replacement of your
current systems and thirdly, a component replacement which means either replacing the lamp or adding
simple control systems. The first option, a full renovation, offers the largest potential
energy savings and hence the greatest cost savings during the lifetime of the lighting.
This involves a new lighting design which can often reduce the amount of light fittings
needed. Such a new design allows you to use state of the art energy efficient lighting
solutions. For general lighting in the working areas these include TL5 fluorescent lighting,
which are the most efficient solutions available today. Solutions here include the Philips
Smartform with its very high optic efficiency of up to 95% and it’s state of the art Actilume
lighting controls, up to 80% energy savings. Another runner here is the TBS257 which offers
energy savings up to 60%. For general lighting in corridors and meeting areas in addition
to using TL5 fluorescent solutions you could also consider a new generation of downlights.
Solutions here include Fugato and LED solutions like the Philips LuxSpace downlight range
which offer energy savings of up to 50%. For accent and more decorative effects you can
consider solutions such as SpotLED, CoveLED and Fugato with muster colour lamps. Savings
here can reach up to 80% compared to Halogen solutions. Your second option for switching to energy
efficient lighting is the one to one luminaire replacement. This means replacing an older
luminaire with a new one which will fit directly into the hole in your ceiling. This in turn
allows you to choose new lighting systems with the best light sources, luminaire optics,
electronic control gear and built in controls. These improvements will allow you to reduce
the number of lamps and hence power consumption you need, although the light quantity and
quality should either remain or increase, lets look at some examples. In many offices
the general lighting is provided by traditional luminaires with 4 x 18 watts TLD lamps equipped
with a cover optic or a simple mirror louver and operated by an electro magnetic ballast.
These luminaires can be replaced on a one to one basis for example by a Philips Smartform
luminaire with 3 x 14 watts TL5 lamps and equipped with a very highly efficient mirror
optic. By doing this the energy consumption is reduced from 92 watts to 48 watts saving
48% on the energy consumption. When the new luminaire is equipped with a Luxsense daylight
sensor additional savings of 30% are realised bringing the total savings up to 65%. Even
better is to equip the luminaire with Actilume controls and bring the total savings up to
80%. Another example are the traditional dicroic halogen spots with electromagnetic transformer
which can also be replaced with Philips SpotLEDs reducing energy consumption from 56 watts
to 12 watts saving 80% of energy. An additional benefit is the huge gain in lamp lifetime
from 2000 hours for the halogen lamp to 50000 hours for the LED solution. Your third and
final option for switching to energy efficient lighting involves changing the lamps and adding
simple controls to your existing lighting, there are several options here too. In 2007
Philips launched a new fluorescent lamp called the TL-D eco, which can directly replace standard
or master TLD lamps whilst saving 10% and if you have standard dicroic halogen lamps
in your reception areas for example you could switch these for Philips Masterline ES lamp
which can save up to 40%. Additional savings up to 80% with LED retrofit. Standard incandescent
bulbs of course should be replaced by compact fluorescent lamps saving up to 80% of energy.
LED retrofit solutions are now also available for incandescent bulbs up to 40 watts. The
50000 hour lifetime makes this LED lamp a truly fit and forget solution. Another benefit
is that air conditioning costs should also be reduced as less heat is generated by energy
efficient lighting. For new installations this means that a reduced air conditioning
capacity is possible saving on initial cost too. And one more thing, don’t forget lighting
controls. The Philips Occuswitch is a simple to install sensor which switches off the lighting
in an office when nobody’s is present, this offers additional energy savings of up to
30%. All these energy saving solutions and many more besides are available today. Together
we can save energy, money and our planet.