conditions for the equipment, resulting in lower
energy use. But if cooling towers are used for space
conditioning, these facilities may quickly become
large consumers of water.
Cooling towers can use more than 250,000
gallons of water daily. While standard practices
have greatly reduced water use through installation of low-flow plumbing fixtures (urinals that
flush with a pint of water and hand-washing
sinks using 0.5 gallons per minute) and high-efficiency irrigation systems, there is much room
for improvement in mechanical and process
systems. Water-cooled systems often are more
efficient than air cooled but can introduce strain
to local aquifers, leading designers to focus on
integrating water reuse strategies.
The term “net zero water,” similar to the definition of net zero energy, means consuming and
returning the same quantity and quality of water
to the watershed on an annual basis. Reaching net
zero water use begins with strict water conservation programs, followed by reuse and reclamation
applications. Opportunities to use collected rainwater and stormwater also must be considered.
Construction projects always will have a budget,
and even when quick paybacks are demonstrated,
projects still must meet budgets. When evaluating
strategies with higher price tags, look at opportunities to save elsewhere. How much perimeter
ductwork is eliminated by installing triple-pane
windows? Does the reduced ductwork labor and
materials offset the higher cost of thermally superior windows? In most cases, it will. Shift dollars
to accurately evaluate first costs.
Net zero waste is similar to net zero energy and net
zero water, resulting in a waste stream that never
enters landfill. Solid waste must first be reduced,
through procurement and packaging policies.
Airports can re-purpose materials to the greatest
extent possible, and maximize use of recyclables
and compostable materials. Many airports may
have land resources that provide a cost-effective
opportunity for onsite composting.
A recent runway replacement program included
recycling more than 65,000 tons of concrete pavement for reuse on site as base aggregate for parking and building pads. In excess of 98 percent of
waste was diverted from landfill. This provides an
example of resource reuse that is now
common practice with cost benefits.
An energy savings performance contract (ESPC)
is a project delivery method in which a single
contract provider executes both the turnkey
implementation of energy-efficiency measures and
a measurement and verification process to track
performance. As a key feature of these projects,
the ESPC provider guarantees the project will
realize the anticipated energy savings. Should the
resulting savings not meet the guaranteed level,
the ESPC provider pays the difference. As a result,
the relationship between the aviation facility and
the ESPC provider is a true partnership, working
cooperatively toward a common goal.
Design-build is a method of project delivery in
which one entity — the integrated design-build
team — works under a single contract with the airport or airline to provide design and construction
services. Collaborative project management means
work is completed faster with fewer problems. The
integrated team is geared toward efficiency and
innovation to meet high performance needs. The
design-build approach can save money and time
by transforming the relationship between designers
and builders into an alliance that fosters collaboration and teamwork. A
Carrie Bradley, AIA, is senior sustainability specialist for Burns
& McDonnell. She may be reached at firstname.lastname@example.org.
2010 2010 Best Civil Engineering Firm To Work For
The goal is mainstreaming green
construction, with no higher
perceived or realized first cost. For
example, low- and zero-VOC paints
were limited and only available
at premium cost a few years
ago. Due to market demand and
transformation, these products now
are available to the general public
through home improvement stores,
with little or no cost premium.