
Interior Lighting
Lighting Overview
The majority of the indoor and outdoor lighting in homes today is
provided by incandescent lamps, commonly referred to as conventional
"light bulbs".
Although incandescent lamps are inexpensive, they are not very efficient
in terms of converting electricity to light. Only about 10% of the
energy consumed by incandescent lamps is actually used to produce light,
the rest of the energy turns into heat. While lighting your home may
account for only 5 to 10% of your total energy use, the excess heat
produced by incandescent lamps can increase your air conditioning costs,
wasting even more of your energy dollars. Lighting your home more efficiently
may involve changing the way you use lighting, or the amount of lighting
you use. It can also mean changing the types of lighting in your home.
Types of Lighting
Incandescent Lamps:
The light bulb is the most widely used lamp in residential and many commercial
and industrial lighting applications. Light bulbs have changed very little
over the years. They are the least expensive form of lighting product, in
terms of initial cost, but they are also the most expensive and inefficient
light source.
Halogen Lamps:
These lamps are a type of incandescent lamp. They
have a longer life than conventional light bulbs, but they are only slightly
more efficient. Halogen lamps are best suited for lighting areas where
a direct focus of light is required.
Linear Fluorescent Tubes:
More light is produced from these lamps than from many other light sources.
These lamps are the most common source of lighting in commercial facilities
and can be found in many homes as well. Linear tube-type fluorescent lamps
and fixtures have improved greatly over the last ten years. For home use,
lamps vary in size from 2 feet to 5 feet in length.
Compact Fluorescent Lamps (CFL's):
These lamps use the same technology as linear tubes, but are designed to
take the place of incandescent lamps. The smallest CFL's are just 4 - 5
inches long and 2 - 3 inches in diameter. They incorporate a ballast and a
screw base adapter to accommodate their use in many indoor and outdoor
applications. Although CFL's are more expensive than standard light bulbs,
they use only one quarter of the electricity and can last more than 10 times
as long as an incandescent. In the long term, taking into account replacement
costs, they are actually the more economical alternative.
The Sun:
An excellent light source. A small amount can provide enough light for an
entire room and can be the equivalent of dozens of incandescent lamps.
It’s also environmentally friendly and free.
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Lighting Comparison
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Incandescent
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Halogen
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Linear
Tube
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CFL
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Efficiency
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Poor
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Poor
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Good
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Moderate /Good
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Light output
per watt
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5 to 15 lumens
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15 to 20 lumens
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80 to 90 lumens
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30 to 70 lumens
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Cost
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Excellent
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Moderate
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Moderate
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Moderate
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Lifetime
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Poor (750 to 1,500 hours)
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Moderate (3,000 approx. hours)
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Good /Excellent (10,000-20,000 hours)
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Good (10,000 approx. hours)
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General Tips
- Make the most of natural daylight. There is no better source
of light than natural daylight. You may need to rearrange some things
to make the best use of daylight, but it's well worth the change. Consider
adding a sky light to bring more sunlight to dark areas. Light colored
interiors help to make the most of natural daylight and other lighting
as well.
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Turn off the lights when not in use. Make it a habit to turn off the
light when you leave a room. If you have children, assign them the
responsibility of acting as "light police". Consider installing occupancy
sensors, which automatically turn lights out when no one is in the room.
Timers can be useful when you're out for the evening or on vacation.
Use motion sensors on outdoor security lights.
- Use incandescent lights sparingly. It takes two 60-Watt bulbs or four
40-Watt bulbs to provide the same amount of light as one 100-Watt bulb.
Follow manufacturers' directions for maximum wattage requirements.
Also, use the minimum wattage necessary. Many major manufacturers
make "Energy Miser" type bulbs, which use 5% - 13%, less energy. Consider
using dimmers in areas where full lighting is not always required.
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Use "task" lighting wherever possible. You can save energy by reducing
background lighting and focusing light right where it's needed through
the use of "task" lighting. Turn off ceiling lights and use table lamps,
track lighting, or under counter lights installed in work and hobby
areas and in kitchens.
- Replace incandescent lights with compact fluorescent lights. Remember
that fluorescent lighting is the most economical choice in the long run.
Almost all lighting in the home can be provided by compact fluorescents
without any modifications to your existing light fixtures. Don't use
ordinary CFL's in light fixtures controlled by dimmer switches you will
need special CFL's for these fixtures.
- For outdoor applications, use compact fluorescent floodlights, metal
halide, or high-pressure sodium lights. High-pressure sodium lamps use
70% less energy than a standard floodlight and last up to eight times
longer. Use light-sensing switches to turn lights on at dusk and off at
dawn, or better yet, motion detectors that turn on the lights only when
movement is sensed.
- Install linear, tube type, fluorescent light fixtures in areas like
kitchens, work areas, garages and basements. If you are remodeling or
even planning a new home, install permanent fluorescent fixtures where
design permits. There are a wide variety of fluorescent fixtures on the
market today,making it easier than ever to combine aesthetics and energy
efficiency.
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