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Where can I find information on
government funding programs?
On our Funding
Assistance page.
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Approximately how
long does a typical lighting retrofit take?
A retrofit typically involves the 5 stages described
on Our Services page. After the design is completed, the
implementation may take from a couple of days for a parking garage to a couple of weeks, if the whole
building is being retrofitted.
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Exactly how much energy
can I save?
If your lighting system is more than about 20 years
old, you can typically save 40 to 70% of energy used for lighting. A simplified upgrade may yield
faster payback, while a comprehensive quality-enhancing upgrade would result in longer-term savings.
As the owner or manager of the building, you should request from your service provider a detailed
economic analysis of the options available before committing to a project.
A later question gets
into the technical aspects of a typical office lighting retrofit. Our clients have saved thousands of
dollars using commercially proven state-of-art lighting (see Case Study).
Ask us for
a CONSULTATION to determine your exact savings.
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In what regions does
your company operate and what buildings do you retrofit?
We are based in Ottawa. Let us know about your
project, we have the capability to retrofit commercial and institutional buildings anywhere in Canada.
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How can the quality of lighting be improved?
We get into this topic at length below. The short
answer is, using state-of-art lamps and luminaires and above all, knowledgeable design. The rest of
this site, including our page of Useful Links, will give you some idea
of what is involved.
Here is an example of the kinds of information you
will find here: Most people are familiar with how unnatural skin tones appear under "daylight"
fluorescents. These fluorescents distort colours, making people appear 'sickly'. Many buyers switched
to "warm white" fluorescents, only to discover that these just cast a pinkish hue over the area but
don't really improve the true colour rendering of people or objects. (They are also a poorer
investment, see What about "full spectrum" lamps and other new
ideas?). Below, we explain why the best solution is to use a lamp with a good colour rendering
ability.
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What are the best lamps on the
market today?
If you are looking for "fixtures", or luminaires,
you should probably visit a lighting showroom or distributor, many of whom have links on this site.
Once you have an idea of the 'look' you are after, come back to this site before committing to a
purchase. Unless your operating hours are very short, selecting luminaires based on aesthetic needs
alone is the most common cause of high operating costs later.
Now, about "light bulbs", or lamps: While it
is certainly possible to identify the best lamp for a given application, an economic analysis
must be a part of that process. The initial cost is usually less than 5% of the total lifetime cost.
The remaining 95% is mostly the cost of energy, and to a smaller degree, the cost of maintenance. So,
the efficacy of the lamps (measured in Lumens/watt) is an important factor to work into the analysis.
Lumen is the basic unit of light output; efficacy translates directly into amount of light output
per dollar spent.
Sodium lamps (HPS and LPS) currently achieve the
highest Lumens/watt. This is why they are so popular for street lighting. However, if your application
requires good colour rendering, they are not suitable (See the question OK, so
how do you measure the quality of light? below). Metal Halide lamps come close to the efficacy
of HPS, and provide a much better quality light. And T5/T8 fluorescents provide a very attractive
combination of efficacy, quality and initial cost.
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Where can I purchase these
great lamps?
You really have to deal with a wholesale lighting
distributor (some of whom are listed on our Useful Links page). Each
lamp manufacturer makes virtually hundreds of different lamps, each with its own balance of
characteristics. Home stores now offer a lot of choice, however as a result of the market demand for
variety at the lowest possible price, they seldom offer a choice of quality. For example, most linear
and compact fluorescents offered at retail and big box outlets continue to be those with poor Colour
Rendering Index (CRI). (See the question OK, so how do you measure the quality
of light? below.)
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What about LEDs?
LEDs (Light Emitting Diodes), or SSL (Solid State
Lighting), is a technology that - everyone agrees - has great potential. LEDs are already the lamps of
choice in many applications, among them exit signs, traffic signals, truck taillights and "ribbons of
light". They last a long time (more that 10 times longer than a typical light bulb) and, in theory at
least, they should have a high efficacy. Some of the problems still being worked on
are heat dissipation (at the kind of power levels that would make them suitable for general lighting),
and CRI (See the question OK, so how do you measure the quality of light?
below.)
We are seeing LEDs in decorative and display
lighting, flat-panel TVs and other specialized uses now, and more and more in generalized interior
lighting. Here at the office, we are taking 7:5 bets on the first building to be lit entirely by LEDs
before year 2020.
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OK, so how do you measure the
quality of light?
Thought you would never ask! The basic measurements
have to do with:
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The total
amount of light (output), measured in Lumens.
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How well
does the lamp convert electricity into light (efficacy), measured in Lumens/watt.
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Colour
(Correlated Colour Temperature - CCT), measured in Kelvin (K). This varies from the warm tones of a
candle, at about 2200K to the cool-blue light of the northern sky, at about 9500K (somewhat counter
intuitively, the "cooler" colours have a higher K number).
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Colour
Rendering, or how true-to-life does the colour of lit objects appear. This is measured by the Colour
Rendering Index (CRI), which varies from 0 to 100. By definition, incandescent lamps have a CRI of
100, same as natural light. Lower CRI will cause colours to change (shift) compared to when viewed
under natural conditions. CRI over 80 is considered good, while CRI under 60 is poor. A difference
of 10 in CRI is noticeable.
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Other
characteristics to consider are: Life (in hrs), Lumen depreciation (decrease in light output over
the lamp life), flicker and noise (caused by old technology fluorescent ballasts), restrike time
(the "wait period" after a power interruption), dimmability, beam pattern (in conjunction with the
luminaire) and of course, cost.
Most people are familiar with how unnatural skin
tones appear under "daylight" fluorescents. Leaving aside the fact that "daylight" is a meaningless
term (natural light can have a CCT of anywhere between1800K and 10000K, depending on the time of day
and sky conditions), it is actually the low CRI (about 62) of the "daylight" fluorescents that is the
problem. The solution is to use a light source with a CRI over 80.
Latest generation T5 and T8 fluorescents are
available with CRI of 85 or even better, approaching the colour rendering capabilities of incandescent
and halogen lamps, while providing 5 times their efficacy.
Good lighting designers start by understanding the
uses of a given space, and the implications of those uses on the quality of light required. As with
any capital purchase, there is an optimal balance between cost and quality. All costs should be
factored in, starting with the initial cost, but also the costs of operating and maintaining the
system, and even of its disposal.
If you are interested in more detail on this topic,
the sites listed in Useful Links have good discussions of these
concepts. Excellent web courses are available from the
Illuminating Engineering Society of North America (IESNA).
For an engineering summary of the advantages and
limitations of the current lamp technologies, as characterized by the three most basic metrics, LPW,
CCT and CRI, see the following presentation by our chief engineer, Milan Javor (click to view, or
right-click and choose "Save Target As ..." to download):
"Measuring the Quality of Light" (3 MB).
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The old T12 fluorescents in our
office are 34W for each 4' long tube, while the new-fangled T8 are 32W. How can you be seriously
saving energy by replacing the old tubes with new ones?
It's not that simple; please don't try to plug in a
T8 fluorescent in place of a T12 without having the ballast replaced first!
A T12 fluorescent is nominally 34W. It is called
"Energy Saving", because it was a real innovation 25 years ago when it replaced T12s that used to be
nominally 40W. The name is inappropriate today. When you take into account the electromagnetic
ballast, a T12 uses 36W for each 4' tube.
The new technology T8s are 32W, but in name only;
with an electronic ballast they actually use 29W. (In both cases, we are using the "normal" ballast,
with a factor of .88). As a welcome by-product of upgrading to modern ballast technology, we will lose
the flicker and hum that gives fluorescents a bad name and some office workers headaches.
Even though the T8s and the T12s produce similar
Lumen output when new, the T8s suffer only about 8% Lumen depreciation over their life, about half as
much as the T12s. So when you work out the numbers, T8s give you 38% more useable Lumens for the same
input power.
This is, however, only half the story. In
addition to fluorescent lamps, offices frequently have pot-lights, exit signs, and decorative
lighting, all of which have energy-efficient alternatives. And over the last 15 years, design
guidelines gradually evolved to recommend lower levels of general illumination, better suited for
viewing computer screens. Task lighting is now the preferred manner of providing the higher light
levels where needed. These simple measures alone frequently save 50% of energy used for lighting a
typical office.
Even higher savings are possible, using the
revolutionary concept of turning the lights off when not needed. For washrooms, storerooms and other
seldom-used areas, occupancy sensing can reduce 90% of energy use. Other measures include "daylight
harvesting" - dimming or turning the lights off (automatically) in areas with sufficient natural
light. Whenever possible, buildings should be designed to take advantage of natural light, but that's
a whole other topic and we'll leave that rant for another day.
There is still more to the energy story though, as
recent research has identified yet more ways of saving energy. See the question
What about "full spectrum" lamps and other new ideas?
Our clients have saved thousands of dollars (see Case Study). Ask us for a
CONSULTATION to determine your exact savings.
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What about "full
spectrum" lamps and other new ideas?
Research results published in the 1990s (so they are
really not that new), improved our understanding of the response of the human eye to light.
"Full spectrum" lamps are an ingenious marketing plan to commercialize the observation that visual
acuity improves under light with more "blue" in the colour mix. This is because such light constricts
the pupil and a smaller pupil size helps the eye focus better, especially as we age. It turns out we
were correct all along: we prefer "warm", reddish light for setting a romantic mood. Now we know it
works by defocusing the eye. You work out the social implications.
How does this affect the practice of energy-efficient
lighting design? In the classic study from 1995, Intel Corporation engineers found that even though
they reduced the lighting levels from 65 fc to 45 fc (fc, or foot-candle is a Lumen per square foot),
people were complaining that the space was too brightly lit! This was because they used 5000K,
commercially available T8 fluorescents (known as '850' in the catalogues), to replace the previously
installed 3500K T12s ('735'). These measures achieved a 57% reduction in energy use!
Even though few lamp manufacturers include the
relevant metrics in their product catalogues (S/P, the scotopic to photopic ratio), experienced
designers now use these findings to create spaces people like, while reducing energy use. And while
using industrially available products, to keep the purchase costs low.
If you have a deeper interest in this topic, see the
report titled Full Spectrum Light Sources, available from the
Lighting Research Center.
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How can I treat the symptoms of
Seasonal Affective Disorder?
Seasonal affective disorder (SAD), or "Winter Blues",
is a type of clinical depression. Symptoms include excessive eating, sleeping and weight gain during
the fall or winter months. Light therapy, preferably in the morning, has been used with success in
treating SAD, but other treatments for depression (for example, medications) are also effective.
If you believe you suffer from SAD, see your
doctor first! Your depression may be due to other causes and light therapy may not be right for
you if you suffer also from other medical conditions (for example, eye disease). As with many medical
treatments, the effectiveness of SAD phototherapy will vary between individuals, and medical
supervision is required for assessing the effectiveness of the treatment and adjusting the strength
and duration of exposure.
There are many light therapy devices available, but
they are not well regulated in Canada. Therefore, be cautious. You should select only devices that: 1)
were scientifically tested, 2) do not emit ultraviolet radiation, 3) are CSA or UL approved in Canada,
and 4) the company has a track record of reliability. Please see the
Canadian Mental Health Association
page on SAD or other sites on our Useful Links page
for specific recommendations.
