Page 124 - Green Building Through Integrated Design

INCENTIVES AND BARRIERS TO GREEN BUILDINGS 101

Concrete
Slab
Structural
Beam
Chilled Beam
Extruded
Mullion Cap
Indirect/direct
Lighting Fixture
Exterior
Sunscreen

Insulated
Low-E Tinted
Glass

Underfloor Air
Control Discs
Insulated
Exterior Wall
Raised Floor with
Cool Supply Air and
Electrical/Data Lines
Fin Tube
Heat Register
Concrete
Slab
Figure 6.2 At the Signature Centre, an underfloor air distribution system
supplies air at low pressure and velocity through floor diffusers. The air rises
through natural convention and exits through a return air shafts centrally located
at the core. This system uses far less energy than conventional overhead air
distribution and allows more use of “free cooling” from outside air, because the
entering air temperature is typically 8 degrees warmer. Courtesy of Aardex, LLC.

technologies and components that make enduring, sustainable contribution and
reject those that don’t.
For example, we became aware that the benefits of an underfloor air delivery system
(Fig. 6.2) were significant and believed it was the way we wanted to go. On the sur-
face, it appeared that the first cost increase was substantial. The cost of the underfloor
system alone was about $7 or $8 per square foot, installed. When simply considered
for first cost, most developers wouldn’t even consider it because it’s a huge increase
in expense. But in our case, we were able to consider it for many of the things it
allowed us to do, such as remove all of the ducting in the building. We essentially
have no ducts other than four vertical supply and return ducts. It also allowed us put
all of the power and data wiring underneath the floor in a plug-and-play situation,
which reduced the amount of electrical material and labor expense substantially.
Another major benefit was that it allowed us to reduce the floor-to-floor height by