Weatherization by fionan


									Lighting                                                            Lighting efficiency
                                                                    Even though there are probably about 10,000 different
                                                                    lamps available from the major manufacturers, there are
In our homes, we tend to use a large variety of lamps and           really only two "types" of lamps used for general lighting.
fixtures to provide us with our lighting needs. In the living
room, we may have table lamps, track lights or cove lights          In a filament lamp, light is emitted by a tungsten wire,
to provide mood lighting, while in the kitchen and                  which gets hot from electricity passing through it. A
bathroom we may have more direct, task-oriented lighting.           halogen lamp is a filament lamp with a halogen gas in it.
Outdoors we may also have common ordinary incandescent              This allows the filament to burn hotter and more efficiently
bulbs or high intensity discharge fixtures. Very few homes          while putting out a whiter light. Halogen lamps also last
use a single lamp type; therefore, we need to be aware of           longer than regular incandescent lamps.
the variety of choices.
                                                                    In a gas discharge lamp light is emitted directly by atoms in
Most of the time, we tend to choose a lamp and fixture by           the gas through which an electric “spark” is occurring. A
their price rather than by their efficiency. If you do this,        gas discharge lamp is like a controlled bolt of lightning that
you may be paying more for lighting than necessary. It is           goes on and on. The ballast regulates the discharge and
common for manufacturers or retailers to lower prices on            ensures that the current does not stop after an electric
items that operate under old technology principles in order         charge “discharges” itself. Gas discharge lamps are much
to liquidate their inventories and make room for the “new”          more efficient than filament lamps, but they require a
items. Be careful not to get caught in this trap and shop           ballast to operate them: they cannot be directly plugged into
wisely.                                                             the electrical line. Fluorescent lamps are considered low
                                                                    intensity discharges while high intensity discharge lamps
New lighting products are not only more energy efficient,           include mercury vapor, metal halide and high-pressure
they offer many more possibilities to improve the quality of        sodium lamps.
lighting in our homes, indoors and out.
                                                                    Here is an energy efficiency ranking by lamp type.
How to compare cost and efficiency                                                                                            Lighting Efficiency Comparison
Why would you buy a $20 compact fluorescent bulb rather                                                     Least Efficient                                             Most Efficient
than a $1 incandescent? Because the more costly efficient
bulbs produce more lumens (light) per watt (electricity                              Low Pressure Sodium

used) than the cheaper bulbs, and last up to 10 times longer,
making them a better bargain in the long run. The two basic                          High Pressure Sodium

pieces of information you need to find the best buy and the
                                                                                             Metal Halide
right product are right on the package.
                                                                      Light Source

Watts – This is often the only number people look for when                                 Mercury Vapor

buying a light bulb. It tells how much power the bulb
                                                                                         Tube Fluorescent
consumes, but nothing about the light output.
                                                                                     Compact Fluorescent
Average lumens – This is the amount of light given off by
the bulb.                                                                                        Halogen

              Efficiency = Lumens per watt                                                   Incandescent

For example: A 75-watt incandescent bulb uses 75 watts of                                                   0      25         50      75    100    125   150      175      200       225
electricity and provides 1,200 lumens. A 20-watt compact                                                                           Efficiency (Lumens per watt)
fluorescent uses 20 watts of electricity (one-fourth the
amount) and provides the same amount of light (1,200
lumens). Compact fluorescent is the better deal.

Residential Energy Assessment Program                                                                                                                               Lighting
As the graph shows, incandescent are the least efficient            You’ll get the most benefit by switching to CFLs wherever
lamps available. They provide an adequate range of                  you use high wattage incandescent lamps more than three
lumens, but also, consume large amounts of watts in                 hours per day – often in the kitchen and family room.
comparison to the amount of light they provide.
                                                                    Halogen torchieres
The most common lamps found in our homes are                        Energy concerns and well-publicized fires have increased
incandescent (bulbs, reflectors, flood lamps), halogen,             interest in alternatives to halogen torchieres. Manufacturers
compact fluorescent, and full size fluorescent (tube                have designed torchieres that use A-lamps, compact
fluorescent).                                                       fluorescent lamps (CFLs), or metal halide lamps instead of
                                                                    tubular halogen lamps.
Compact Fluorescent Lamps
No other new product in the                                         Why halogen torchieres are so popular
lighting industry has had as                                        Halogen torchieres are
great an impact as the compact                                      popular with consumers
fluorescent lamp (CFL). CFLs                                        because of their appearance,
are smaller versions of                                             light distribution, versatility,
standard fluorescent lamps.                                         availability, and cost.
They consume between 5 to 40                                        Torchieres provide indirect
watts, and have a brightness                                        lighting, which means they
and color rendition that is                                         illuminate spaces by
comparable to incandescent                                          reflecting light off ceilings
lights. Unlike standard                                             and walls. They are an
fluorescent lamps, they can                                         inexpensive source of
directly replace standard                                           indirect lighting that does not require an electrician to
incandescent bulbs.                                                 install. Their slim, upright design helps them fit into almost
                                                                    any decor. Torchieres make it possible to change the
The following is a comparison between the wattage of                ambiance within a space by moving the torchiere or
commonly available incandescent lamps and the wattage of            dimming the lamp. They are lightweight and can be easily
a CFL that will provide similar light levels:                       moved from room to room. Halogen torchieres are often
                                                                    sold with continuous dimming, or bi-level or tri-level
     Incandescent           CFL                                     switching.
     25 Watt         =      5 Watt
                                                                    Ninety percent of the halogen torchieres sold in the United
     50 Watt         =      9 Watt
                                                                    States have 300-watt halogen lamps. Halogen torchieres
     60 Watt         =      15 Watt
                                                                    have been widely available for years at department stores,
     75 Watt         =      20 Watt
                                                                    lighting distributors, home improvement centers, and other
     100 Watt        =      25 Watt
                                                                    retail outlets at prices as low as $10 to $15.
     120 Watt        =      28 Watt
     150 Watt        =      39 Watt
                                                                    Problems attributed to halogen torchieres
                                                                    Three-hundred-watt halogen lamps reach operating
Modern CFLs have taken the best aspects of fluorescents –
                                                                    temperatures high enough to ignite paper, cloth, wood, or
high efficiency and long life – while eliminating traditional
                                                                    plastic that is tossed into, blown into, or draped over the
problems of poor color, flicker and noise. Although, CFLs
                                                                    lamp. In some cases, fires have started when torchieres
still cannot be used with dimmer switches and do not
                                                                    have fallen over and touched carpet, drapes, or bedding.
perform well outdoors in cold weather. They cost an
average of $10 to $25 per bulb, but they last ten times
                                                                    In 1996, Underwriters Laboratories (UL) withdrew its
longer than incandescent and use 60 to 75 percent less
                                                                    listing for halogen torchieres with 500-watt lamps to reduce
                                                                    the risk of fire. They urged consumers to replace 500-watt
                                                                    lamps with 300-watt lamps.

Residential Energy Assessment Program                                                                                     Lighting
When tubular halogen lamps fail, they sometimes explode             Don’t use “long life” incandescent bulbs – they may last
or shatter. Careful handling is required because oils from          longer, but put out much less light than a regular
the skin make the lamps susceptible to shattering while             incandescent, while still consuming the same amount of
operating. For this reason, a tempered glass "shatter shield"       electricity. In places where changing a bulb is difficult and
is required in halogen torchieres to enclose any fragments          a long life lamp is desired, consider a compact fluorescent,
of hot quartz glass that can scatter on nearby combustibles.        which lasts ten times longer than a standard incandescent.
This shield closely covers the lamp and offers very little
heat protection. The shatter shield should be reinstalled           Do purchase energy-efficient incandescent bulbs instead of
every time the lamp is replaced. Unfortunately, some                the standard 60, 75 and 100-watt bulbs. They will save 5 to
consumers disregard this precaution.                                10 watts per bulb with little or no change in light output.

In addition, halogen lamps might not provide the energy             Don’t use devices containing “diodes” (coin sized disks
savings that are sometimes advertised for them. Although            that install into lamp sockets) that claim to increase the life
some halogen lamps provide 18-20 lumens per watt (LPW),             of a bulb. With these devices, light output drops
researchers found that the average imported halogen lamp            dramatically, and they may pose a safety hazard since they
produced less than 12 LPW--40% less than a 100-watt A-              cause an electrified portion of the lamp base to be exposed.
                                                                    Don’t purchase expensive “full spectrum” fluorescent
Although halogen torchieres are inexpensive to buy,                 lamps that exaggerate the benefits of ultra-violet light.
operating cost makes them more expensive overall than               Currently there are no products on the market made to fit
most energy-efficient luminaires. The electricity costs of          standard household fixtures which provide the suggested
operating a halogen torchiere can be quite high, about $44          therapeutic value offered by true full-spectrum lights.
per year (assuming a 300-W lamp, operated for four hours
every day, at 10¢ per kilowatt-hour).                               Do make sure your fixtures have been tested for safety and
                                                                    listed by an independent agency, such as UL or ETL. Look
Electronic Controls                                                 for one of these designations on the fixture before
A number of easy to install lighting controls are available         purchasing.
that will increase your lighting flexibility, your home
security and your energy savings.                                   Do check the light output in “lumens” on the package when
                                                                    you buy different brands of bulbs.
• Electronic dimmers, especially popular in dining rooms,           Some off-brands may have a lower purchase price, but
regulate the brightness of incandescent and tungsten                provide less light output.
halogen lights, allowing you to create an informal, relaxed
atmosphere – and they save energy.                                  Daylighting
                                                                    An excellent strategy for lighting
• Motion sensing light switches turn lights on and off              energy conservation involves
automatically when someone enters a room, offering “no-             using a free source of energy:
hands” light control for hallways, bedrooms and other areas         the sun. The sun provides
where lights are inadvertently left on, or as part of your          tremendous amounts of light,
home security system.                                               even on a moderately cloudy
                                                                    day. Using this free light may
• Electronic timers provide precise, automatic on-off control       reduce the amount of artificial
of light fixtures and are often used for home security. For         illumination needed in your
instance, they will turn specific lights on automatically at        home. However, using sunlight
dusk and off at “bedtime” making your house appear                  without causing glare and
occupied when you are away from home.                               without overheating a building
                                                                    can be difficult. Glare can be
Lighting Do’s and Don’ts                                            avoided by

Residential Energy Assessment Program                                                                                       Lighting
 Using windowsills, walls, louvers, reflective blinds, and
  other devices to reflect light deep into the building. Be
  careful to locate windows and skylights away from the

 Direct rays to avoid overheating. For example, placing
  skylights on the north slope of your roof rather than on
  the southern exposure may reduce heat transfer. In
  addition, look

 For windows with new selective glazings that transmit
  the most visible light while excluding the most solar heat.

In addition to saving electricity by using the sun, you can
also save on heating energy. Allowing the sun through
your windows in the winter provides you with free heat.
Open your window blinds or shades during the day to help
warm your house, then after sunset, close them to keep the
heat in.

 Source:
 Minnesota Department of Commerce Energy Information
  Center, Techniques, Tactics & Tips, Home Energy Guide
  to Home Lighting
 U.S. Department of Energy (DOE) by the National
  Renewable Energy Laboratory (NREL), a DOE national
  laboratory. Available at:

Residential Energy Assessment Program                               Lighting

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