Environmental Engineering Reference
In-Depth Information
a few exceptions in the United States, and once again it is
California that is the leader. The California Energy Com-
mission says that the energy savings from these codes has
already amounted to about
$
per household since
they were
. The residential code
has been revised several times, most recently in
first adopted in
.
ciency building codes are in
Europe, where the energy use per square foot of
The best energy ef
oor
space tends to be lower than in the United States. The
strictest standards may be in Switzerland, though
I confess I have not looked at the codes of many of the
European Union members. There is a move in the United
States to sharply reduce energy consumption in buildings
over the next few decades. Among the states, California is
once again taking the lead. Their new goal is that new
residences use zero net energy (ZNE) by the year
,
and new commercial buildings use ZNE by
. ZNE is
de
ned as having enough clean electricity generated on
site so that averaged over the year no net energy is used
from the electrical grid. It is not clear what ZNE means
with respect to heating.
The federal government has a
goal for all new federal buildings of ZNE by
, and
their de
nition is that electricity usage be reduced by
%
and the remaining
% come from carbon-free energy
generation either on site or off site.
In Germany residences are already being built that use no furnaces for
heating. They are designed with heavy insulation and are sealed against
air leaks. Fresh air is brought in and the heat from the air being
exhausted is used to heat the incoming air. Heat is supplied from the
other appliances in the home and temperature is adjusted by varying the
air intake.
