Chapter 24 Energy Conservation
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only someone comes near the home instead of
being on all night when they are not needed,
which reduces energy waste.
Hot Water
Heating water is one of the biggest energy
uses in a home. Hot water is used for many
tasks, such as laundry and showers. Industrial
uses include car washes, boilers in factories,
and various uses in food production. The
problem with heating water is that too much
energy is wasted in the process. There are a
number of ways that energy can be conserved
and the cost reduced.
The ways to conserve hot water are simple.
Only use hot water when needed, and try not
to use it for longer than needed. The way hot
water is used is not the only way it can be
saved. The type of hot water heater can also
make a big difference.
Normally, water is heated in a tank,
making it ready for use. However, if a faucet
is turned on the other side of the house, far
away from the water heater, cold water goes
down the drain until hot water arrives at the
faucet. Some companies produce a product
that is mounted under the sink that produces
instant hot water when the faucet is opened.
These units eliminate wasted energy.
A recirculating pump can also be used
so that the cold water is not wasted. When
hot water is turned on, but before the water
fl owing is hot, a recirculating pump returns
the cold water to the hot water heater. When
hot water fl ows from the faucet, the water
fl ows down the drain in the normal manner.
Adding extra insulation to the outside of a hot
water heater can also conserve energy because
it allows less of the heat to escape so the heater
runs less frequently, Figure 24-2.
When choosing a hot water heater, select
one with a high effi ciency rating. All hot
water heaters are rated, and the energy rating
is attached to the heater. A water heater may
be compared to other similar models. In this
case, the rating compares it on a scale between
the best and worst possible ratings for its class.
For example, the Energy Guide for the unit in
Figure 24-3 shows it will use 273 therms per
year on a scale between 215 and 283. A therm
is a unit of heat equal to 100,000 British thermal
units. A British thermal unit is the amount of
heat required to raise one pound of water one
degree Fahrenheit. This unit is not very effi -
cient when compared with others in its class.
Another scale that may be used is the
Annual Fuel Utilization Effi ciency (AFUE)
rating scale. In this case, higher ratings are
better. A unit that scores 94.3 out of a possible
97.6 is very effi cient. You may see other rating
scales for energy savings on different items
found in your home.
There are energy effi cient models of most
appliances, such as ranges, dishwashers, and
clothes dryers. Since these are large appliances
Figure 24-2. This hot water heater has been
wrapped in insulation.