Environmental Engineering Reference
In-Depth Information
sides of a doorway. Installing double-pane windows will generate addi-
tional savings, as will adding insulation. The latter two changes will
probably cost hundreds of dollars, but with the ever-increasing cost
of heating oil and natural gas, the money spent will be recouped in
a fairly short time.
The biggest opportunity to improve the energy situation in the United
States would be a major investment program to make homes and busi-
nesses more effi cient. Homes would account for about 35 percent of the
potential effi ciency gains, while the industrial sector accounts for 40
percent and the commercial sector 25 percent.
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Stricter building codes
for energy conservation have been fought by the powerful builders'
lobbies, which contend that they can add $2,000 or more to the cost of
a house. Nevertheless, in a few cities and in California, tough new rules
have been adopted.
Heating water in a typical single-family home accounts for about one-
fourth of the home owner's total energy use. Up to 85 percent of the
water heating cost can be saved by installing a solar heating system on
the roof. In Israel they are required by law, and all dwellings have them.
There is backup electrical heating for the winter months. In the United
States, a solar heating system costs about $2,000 installed (only $1,000
in Israel, possibly because of mass production).
Transportation
Motor vehicles are responsible for almost a quarter of
the annual emissions of carbon dioxide in the United States, so doing
something about how we move from place to place can make a signifi -
cant impact. Americans are wedded to their cars, a tie that has a major
negative impact on both their wallet and the environment. Car owner-
ship accounts for 15 to 22 percent of all household expenditures, and
vehicles powered by fossil fuels are essentially pollution-generating,
global-warming factories on wheels. Two-thirds of the oil used in the
United States is for transportation. Each day we use 350 million gallons
of gasoline, spewing enormous amounts of pollutants into our air and
our lungs (see chapter 10).
Changing the car you drive, however, is the most expensive green
change you can make. As everyone is aware, smaller is better, and
hybrid cars are better for the environment than those that run only
on gasoline. Unfortunately, new cars are expensive, even with a gov-
ernment tax credit for the purchase of hybrids, and most people buy
a new car only when necessary—about every fi fteen to twenty years
on average. Compounding the problem is the much higher cost of
