Lighting is an element of our home and work environment that affects our life in many different ways.
Lighting lets us see to carry out the daily tasks of life; it affects our comfort and mood, and it can
provide safety and security. Lighting and lighting fixtures also play a major role in the interior decoration of our homes.
Our consumption of electricity related to lighting also affects our budgets,
both at home and in our workplaces. The Department of Energy reports that
we spend, on average, 5-10% of our electric bills on lighting in our homes.
In some regions of the U.S. this amount can be as high as 25% where air-conditioning
is a modest portion of the bill.
Your local Sea Gull Lighting distributor can
provide ideas on how you can reduce your home's electric
bill by installing energy-efficient lighting, and will
also provide you with a general overview of home lighting concepts.
As a point of origin, let's look at some basic concepts that will
help us to better understand how these savings can be achieved.
Energy Efficiency with Lighting
Saving lighting energy requires either reducing electricity consumed by the light bulbs and
light fixtures or reducing the length of time that the lights are on. This can be accomplished by:
- Reducing the amount of time that lights are on. This can be accomplished by using dimmers and other lighting
controls, and educating family members to turn off unnecessary lights.
- Lowering wattage, which involves replacing bulbs or entire fixtures with bulbs and fixtures
that provide the same amount or greater amounts of light but with reduced electricity usage. Today, this can be accomplished
most easily by replacing inefficient incandescent bulbs with incandescent/halogen bulbs or compact fluorescent bulbs
Making the appropriate lamp selection
A "lamp" is the term used in the lighting industry to describe what is most commonly called a light
bulb. The key to lighting energy savings lies in the choice of lamp.
There are three primary families of lamps, or bulbs:
- Incandescent
- Fluorescent
- High Intensity Discharge
Historically incandescent lamps have been the most frequently used in residential applications due to their
low initial cost. Incandescent sources, however, are relatively inefficient in their conversion of electrical energy to visible light and can, therefore, add unnecessary electrical costs
to our electric bills.
Fluorescent and High Intensity Discharge lamps have been used most
often in commercial and industrial applications. Their initial cost
is more than incandescent lamps; but they are much more energy-efficient and last significantly
longer.
Due to major improvements over the last few
years in the color rendering abilities of fluorescent lamps,
and the availability of small fluorescent
bulbs called "compact fluorescent lamps" or "CFLs", fluorescent lamps
are now a very viable alternative to incandescent lamps for home
lighting use. As an example, for the same amount of electrical energy, compact fluorescent bulbs
produce 3-4 times more light than an incandescent bulbs.
Incandescent Options
Incandescent lamps are the least expensive to buy but the most
expensive to operate. Incandescent lamps also have the shortest
lives of the common lighting types. They are also relatively inefficient compared with other
lighting types.
The three most common types of incandescent lamps are:
- standard incandescent
- tungsten halogen
- reflector lamps
Standard incandescent
Known as the "A-type light bulb," these lamps are
the most common yet the most inefficient light source available.
Note that a larger wattage
lamp or bulb may not be the most energy- or cost-effective option,
depending on how much light is needed. "Long- life" bulbs,
with thicker filaments, are a variation of these A-type bulbs.
Although long-life bulbs last longer
than their regular counterparts, they are less energy efficient.
The best option to achieve energy-efficiency is to replace "A" lamps
with compact fluorescent lamps, which will be discussed below.
Tungsten Halogen
This newer type of incandescent lighting achieves better
energy efficiency than the standard A-type bulb. These lamps
are more expensive than standard incandescents but can have significant impact on achieving
greater light output than standard incandescent lamps.
Reflector lamps and Parabolic Aluminized Reflector lamps
Reflector lamps (Type BR) are designed to spread light over specific areas and are used mostly in
recessed downlight fixtures.
Parabolic aluminized reflectors (Type PAR) are an excellent replacement for the BR lamps. They have a specially
designed reflector that is highly efficient in pushing light into the space.
Fluorescent
Fluorescent lighting is used mainly indoors, both for general/ambient lighting and task lighting, and
is about 3 to 4 times as efficient as incandescent lighting. Fluorescent lamps last about 10 times longer than incandescents.
To gain the most efficiency, you should install fluorescents in places where they will be on for several hours at a time.
You can also increase the energy savings for existing fluorescent lighting by replacing them with a more efficient model (providing
a lower wattage but approximately the same light output), or by replacing the existing fixture with a more efficient model.
Compact Fluorescent
Compact fluorescent lamps CFLs) are the most significant lighting advance developed for homes in recent years. They
combine the efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures.
CFLs can replace incandescents that are roughly three to four times their wattage, saving up to 75% of the initial lighting
energy. Although CFLs cost from 10 to 15 times more than comparable incandescent bulbs, they also last 10 to 15 times as long. This energy savings and superior longevity
make compact fluorescent lamps an excellent choice for residential use.
As previously discussed, CFLs are one of the best energy efficiency investments available. When introduced in the early- to mid-1980s,
CFLs were bulky, heavy, and too big for many incandescent fixtures. However, newer models with lighter electronic ballasts are only slightly larger than the incandescent
lamps they replace. The new CFLs also produce a better color for the home.
CFLs come in integral and modular designs. Integral CFLs have a ballast and a lamp in a single disposable unit. Modular designs
feature a separate ballast that serves about five lamp replacements before it wears out.
High-Intensity Discharge
High-intensity discharge (HID) lamps provide the highest effectiveness and longest service life of any
lighting type. They are commonly used for outdoor and street lighting, but have very limited applications in homes.
Their residential use is limited to outdoor lighting for driveways, backyards, etc.
Replacing Lamps and Fixtures
" Relamping" means substituting one light bulb for another to save energy. You can decide to make illumination higher or lower when relamping. But be
sure that the new bulb's light output fits the tasks performed in the space and conforms to the fixture's specifications.
Matching replacement bulbs to existing fixtures and ballasts can be challenging, especially with older fixtures. Buying new
fixtures made for new lamps produces superior energy savings, reliability, and longevity compared with relamping.
Energy-Efficiency with Lighting Controls
Lighting controls are devices for turning lights on and off or for
dimming them. The most useful controls for increasing
lighting energy-efficiency in a home are dimmers, photocells, and occupancy sensors.
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Dimmers reduce the wattage and output of incandescent and fluorescent lamps and significantly increase the
service life of incandescent lamps. Dimming fluorescents requires special dimming ballasts and fixtures, but does not reduce
their efficiency.
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Photocells turn lights on and off in response to natural light levels. Photocells switch outdoor
lights on at dusk and off at dawn, for example.
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Occupancy sensors activate lights when a person is in the area and then turn off the lights after the person has left.
They are popular for areas such as closets and recreation rooms.
Energy-Efficiency with Ceiling Fans
Although ceiling fans cannot contribute directly to savings on lighting energy costs, they can contribute
significantly to savings on electrical costs associated with space heating and cooling. Household electrical
costs associated with space heating and cooling are in the range of 35-45%. Using a ceiling fan can help to
cool our homes in summer, and helps to distribute heated air in winter more efficiently.
Although it's difficult to identify an exact savings amount related to the use of ceiling fans, it's an established fact that ceiling
fans can help to reduce electrical costs by creating greater efficiency in how we heat and cool our home environments. Especially
in summer, it's often more comfortable to turn off the air-conditioner at night, and use a ceiling fan at low speed in the bedroom.
To educate your family members on the importance of energy conservation, appoint
a Household Energy Monitor to turn off lights, set the thermostat, and keep
the windows/doors closed if the air conditioning or heater is on. Rotate the position so that all
family members share in the responsibility. For the energy and money your family saves, have a family outing
to celebrate your family's is contribution to energy conservation.