Environmental Engineering Reference
In-Depth Information
In buildings, approaches that optimize individual component efficiencies typ-
ically result in 20-30% efficiency gains in heating and cooling energy use, while
novel approaches focusing on holistic methods using integrated design principles
have been demonstrated to achieve as much as 60-90% energy savings compared
with standard practices.
Passive houses that reduce energy use for heating and cooling by 90% or more
are already found in many European countries. What makes them “passive” is the
fact that very little external energy is used to heat the house in the winter or to cool
it in the summer. Increased investments in building insulation are partly offset by
lower investments in heating and cooling systems, as energy costs for operation are
almost eliminated, making these new options very attractive.
Buildings in developing countries do not usually require ambient heating or hot
water, thus saving significant amounts of energy and costs. In addition, by using al-
most exclusively local materials, production costs can be reduced—such as occurs
in India with low-cost bricks.
Approximately 40% of all energy used today is spent on building construction and
use. Selected energy efficient technologies and practices for buildings are as fol-
lows:
Building en-
velopes
Energy-efficient windows, insulation (walls, roof, floor), reduced
air infiltration
Space con-
ditioning
Air conditioner efficiency measures (e.g., thermal insulation, im-
proved heat exchangers, advanced refrigerants, more efficient mo-
tors)
Centrifugal compressors, efficient fans and pumps, and variable air
volume systems for large commercial buildings
Appliances Advanced compressors, evacuated panel insulation (refrigerators),
washing machines and dryers with higher spin speeds
