Q. I'm not sure what type of
lights to use
(halogen,
LED, incandescent or fluorescent). Why should I use one type over another?
A. For task, accent, and art lights, halogens are a good choice
due to their excellent CRI (color rendering index) value. For
general lighting, we recommend halogen or compact fluorescents
(neutral color temperature) with a CRI of 80 or more. If efficiency
is a major concern, LEDs are an excellent choice for task lights,
courtesy lights and specialty applications such as livewell lights
and compartment lights. In engine rooms, fluorescent lamps with a
cool-white color temperature throw a lot of light and are very
efficient.
Incandescent lamps have good color rendering, are relatively
inexpensive and readily available. However, they are inefficient and
are adversely affected by voltage fluctuations, so they are not the
best choice for many applications.
Q. LEDs are big news. Why don't all fixtures use
them?
A. Although LED's are attractive to boat owners for their
low energy use, their luminous flux is low compared to other light
sources. Several LED's must be clustered together at different angles
to approximate the light output of one standard incandescent bulb.
The angle of illumination can vary (depending on the application).
To achieve enough light (in foot-candles) to illuminate objects, the
LED must have a viewing angle of between 15-20 degrees. Therefore,
bulkhead-mounted reading lights or chart lights are well suited for
this type
of illumination.
For courtesy lights, LED's with a wider viewing angle (lower foot
candles) are a good choice. Up to now, this inverse ratio between
viewing angle and foot-candles has limited LED usage to specific
applications. However, advances in LED technology is quickly
overcoming these trade-of's and we believe LED's will soon
be a practical alternative for general illumination.
FAQ's about lighting
Q. How do I calculate the correct spacing
between my spot lights?
A. Spacing should be at least equal to the beam diameter at
the WorkPlane in order to evenly maintain foot-candle level
throughout an area. "WorkPlane" is defined as the height at which an
activity takes place in a particular room. At this height, imagine a
plane cutting across the entire room (see diagram below). The
WorkPlane is the point at which foot-candles are measured.
Q. Some fixtures have a W symbol in their
descriptions. What does this mean and why is it important?
A. The W symbol indicates the fixture has been approved for
zero clearance. This means the fixture's back side may be in contact
with "normally inflammable" surfaces without heat-related problems
occurring. Some fixtures are available in higher wattage versions
which may not be W rated. In these cases, the fixture will actually
have a ~ symbol printed on its housing, and a block of space 25mm
above and 70mm all around the back pan must be allowed.
Q. How do I choose the right dimmer?
A. First, decide if you need an AC, DC, or low voltage
AC dimmer. Then decide if you prefer rotary (rheostat) control or
momentary push-button control. Once you have narrowed your choice of
dimmer category, you must match the power (Amp rating) of the dimmer
with the total wattage demand of the circuit. Most dimmers have a
10-20% built-in overcapacity, so you don't have to overkill on amp
size.
A useful formula to remember is:
Finally, there are different features that may be
important
to you: multiple-switch capability, memory features, soft-start,
nighttime LED locator, or compatibility with your favorite
decorative face plates (like Gewiss or Vimar).
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Lighting Specialists
Q. How does bulb wattage vary with each type of
light to get the same light output?
A. As the chart above illustrates, light output (measured in
Lumens/watt) varies according to bulb type. Therefore, on average, 1
watt of fluorescent is equivalent to almost
6 watts of incandescent (or 4 watts of halogen).
LEDs are available in narrow beam, medium beam, and wide beam; the
wider the beam angle, the lower the intensity of light output.
Generally it takes between 7-9 LEO's for
adequate reading and task lighting. It can take 20+ LEO's to equal
the light output of a lOW halogen spot (however, it is believed that
we could see a 2-fold increase in the intensity of LEDs over the
next two years.)
Q. There seem to be many different terms used to describe
light intensity or light output. What are the differences between
these terms and how are they measured?
A. Luminous Flux is the total amount of lamp light in
all directions and is measured in Lumens.
Luminous Intensity is the concentration of light in a
particular direction and is measured in Candelas.
Luminance is the density of light on a surface and is
measured in lux units.
Luminance is the concentration of light directed toward the
eye and is measured in Candela/square meter.
Q. How do I dim a circuit that is low voltage AC (powered by a
transformer)?
A. There are two ways to do this. You may dim from the output
side of the transformer using a low voltage AC dimmer, or you may
use a standard AC dimmer on the supply side of the transformer. If
you decide to use a standard AC dimmer, be sure it is rated for
"Inductive" loads. If you prefer to use a low voltage AC dimmer, the
transformer must be compatible (many compact electronic transformers
will not work with low voltage AC dimmers due to their high output
frequency).
Q. Am I limited to the type of fixtures I can use if my low
voltage is powered by transformers?
A. Many larger vessels use transformers to take their 120VAC
or 220VAC down to low voltage 12VAC or 24VAC. This allows the use of
smaller fixtures which use miniature low voltage bulbs. All our low
voltage incandescent, halogen, Xenon bulbs and LEDs will work with
low voltage AC or DC. However, our DC fluorescent fixtures will only
work with straight DC current.
Q. Why would I use a Xenon bulb instead of a standard halogen
bulb?
A. Xenon G4 bulbs are direct replacements for standard G4s.
Xenon lowers the rate of evaporation of the filament, therefore
extending lamp life. Xenon bulbs can last up to five times longer
than standard halogen bulbs and run about 20% cooler on average.
These bulbs are especially useful in 24V systems because the
filaments in 24V bulbs are finer and more damage-prone. For the
ultimate in longevity, choose the 28V version.
The primary drawback to the Xenon is a 15-20% reduction in light
output; they are also more expensive than standard G4 halogens.
Q. What accessories can I use to extend bulb life?
A. We offer two items, a voltage stabilizer and a bulb
saver, which can help extend the life of your bulbs (both shown on
page 39). The Cantalupi Voltage Stabilizer is available in
12V and 24V versions. It is a sugar cube-sized module that is wired
directly to one or two low voltage fixtures (capacity 25W). It will
stabilize the output voltage (to the bulb filament) within a range
best suited for long bulb life. The IML Bulb Saver is a
physically larger and more powerful unit (15 Amps) that can handle
several fixtures at once. One model will operate between 10-40VDC.
However, it simply drops the output voltage nominally by 1.5V
regardless of the input voltage.
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