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Besides lifestyle changes, like remembering to turn off lights,
computers and the TV when you aren't using them, replacing appliances with
more efficient ones is the easiest way to save energy. If you're
already turning things off when not in use, more efficient appliances can
make a sizable difference in your energy usage. The federal
Department of Energy (DOE) manages the Energy-Star program, which
sets maximum energy usage limits for various types of appliances.
Manufactures then submit each model to be tested, and if it meets the
standard, is allowed to carry the Energy-Star label. The Energy-Star
program does not have standards for every type of appliance, and even when
it does most manufacturers only have some models certified.
For most people, the easiest improvement is to buy Energy-Star
qualified appliances, when one is available. Anyone interested in
"best in class" performance will want to look at the actual test
data in more detail, since there can be a huge difference in energy use
among the qualifying products. Those people seriously looking to
reduce their energy use will also need to look at machines in each size
class, since, for example, a qualifying 23Cu Ft refrigerator can use more
energy than a qualifying 16Cu Ft one.
Each type of appliance has its own characteristics: the most
significant ones are described below.
Refrigeration
Refrigerators have come a long way since the 1970s--so much so that ANY
new refrigerator will be use at most half as much energy as a twenty year
old one. A good Energy-Star one might only use a quarter of the
energy as an older one. You can find all the qualifying models by
going to: http://www.energystar.gov/index.cfm?c=refrig.pr_refrigerators.
The best models in absolute energy use are the smaller ones--the larger
models can use as much as 50% more energy than the smaller ones and still
qualify.
Clothes washing/drying
Energy-Star qualified washers have gotten much more efficient, even since
2000. Newer models use less water in addition to reducing energy
use. The difference between qualifying models can be
significant, with the difference between the top model and the least
qualifying one being around 30%.
Measuring the energy use of a washing machine is more complicated than
with other appliances because you not only have to account for the
electric the machine itself uses, but the energy used to heat the hot
water it it uses, and the energy required to dry the clothes when its
done. To further confuse the issue, the amount of energy used
depends on the load size. Some new washers have the ability to adjust for
the load size, rather than having you select it, reducing the hot water
energy used on small loads. However, because the washer still has to
run thru its entire cycle, it will use essentially the same amount of
energy for a small load as it does for a large (depending on whether is
also shortens the wash and spin cycles), so to get the full efficiency,
you will have to fill the machine to its capacity.
Front loading (or machines that operate like them) use less water
because they only use enough water to make the clothes soaked, not a whole
barrel full. Many newer machines also have a very high spin speed
which removes much more water from the clothes, allowing them to dry much
faster--it takes less energy to squeeze water out by centrifugal force
than by evaporative heat. Energy-star qualified machines are rated
by their Modified Energy Factor (MEF), and Water Factor (WF). MEF
takes into account the energy needed to run the machine as well as the
resulting energy needed to dry the clothes (higher is better). WF is
a measure of how much water the machine uses (lower is better). Both
MEF & WF are adjusted for the capacity of the machine, so you can
directly compare the two numbers regardless of machine capacity.
The conventional wisdom is that front loading machines make your
clothes last longer because they don't use an agitator, and hence apply
less force to the clothing (no actual references found).
Dryers all use about the same amount of energy, so Energy-Star doesn't
rate them. The one feature that does make a difference is a moisture
sensor (used in the "auto" cycle). Using the automatic
cycle allows the dryer to shut off when the moisture in the exhaust air
indicates the clothes are dry, whereas in a timed cycle, the dryer runs
until the time runs out.
Dishwashers
Dishwashers are much more efficient than they used to be, generally using
less water and energy to do their job. Since most of the energy used
in a dishwasher is to heat the water and dishwashers use a fixed amount of
water per cycle, its generally most efficient to only run the dishwasher
when its full. Many dishwashers now come with a "soil
sensor" the will eliminate wash cycles when the water running thru
the machine starts being clear, making the "full dishwasher"
rule not quite as critical (note: verify this).
Some machines can heat water themselves, which is an advantage for
people who want to wash their dishes in very hot water. Without
this, the only other option is to turn the thermostat on the hot water
tank up, which causes it to have greater standby losses.
The 'heat dry' cycle often uses a significant amount of energy, and so
by using 'air dry" instead, you will save energy. There is a
sizeable difference between the top performing and minimally qualifying
energy star models--as much as 50%.
Lighting
Compact fluorescent lights (CFLs) last longer and have a better color than
the early model --good enough now that most people finally feel they are
an acceptable replacement for incandescent bulbs. Although they are
still quite a bit more expensive than incandescents, the difference
is smaller than it used to be. Because CFLs contain a small amount
of mercury in the bulb, and have electronics in the base, disposal is a
serious concern. In some communities CFLs are considered hazardous
waste, and must be disposed of specially, but most allow then in the
trash.
The advantage of CFLs is that they use only 1/3 to 1/2 the energy of a
standard incandescent blub.
In the near future it is predicted that LED lighting will be able to
match the efficiency of CFLs, have a much longer lifetime, and not have
the disposal problem. General Electric claims to have a design for
an efficient incandescent bulb that also matches the efficiency of CFLs
that they will be available sometime in the next few years.
Computers etc.
Computers, especially desktop computers, use a lot of electric. As a
rule of thumb, the more "powerful" high end models use more
energy than the standard ones. Laptops, because they have to be able
to operate on batteries use significantly less energy-- a desktop might
use nearly 200 watts, while a laptop is more likely to use around
30. As most desktop users have migrated to using LCD monitors, the
total energy used by the desktop has gone down, shrinking the gap a
little.
Another important feature is to use the energy saving software that
powers down the monitor, hard drive as well as hibernating the machine
when it hasn't been in use for a while. The sooner the machine
hibernates the better, but obviously having the machine hibernate while your
thinking or going on small break is very undesirable.
Modems and routers have become ubiquitous in computer savvy households,
and unfortunately they are usually on 24 hours a day. Since
Energy-star doesn't rate them, there is no way to gage what a good one is
other than by plugging it into a watt meter--an act that's not likely to
be met with enthusiasm by your local big box electronic dealer, nor are
you likely to find its typical power consumption on any manufactures
website.
Consumer Electronics
Any device (like a TV) that has a remote control cable of turning on the
device uses power even when its off, and as a result this use of electric
is called a "phantom load". In my view it is a sad
state of affairs that people are too lazy to walk over and turn the TV on
and off. The easiest fix is to buy a plug strip with a switch, and
turn the switch off when your done. Since most people locate their
TV, DVD and Stereo near each other, you can plug all of them into one
strip and turn the whole mess off.
Some electronic devices (like TVs) have Energy-star standards, which
for the most part limit the device to one watt. While this is a big
improvement over the 3-8 watts that some draw, its still a waste of
electric.
Cordless phones and any other device that uses one of those little
black power supply boxes ("wall warts") also use power any time
they are plugged in. Energy-star does rate cordless phones, but
whether you will be able to find one is another question. For
devices that you only use occasionally (like scanners, faxes, portable
music players) can be unplugged when they aren't in use, or if they have
batteries, when the battery is charged. The biggest limitation
to this scheme is that some batteries are very fussy about how they are
charged/discharged, and charging them any other way than what the
manufacturer recommends will likely result in reduced battery life.
Resources
The energy star site: www.energystar.gov
The American council for an energy efficient economy consumer guide: http://aceee.org/consumerguide/index.htm
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