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Complex and challenging construction projects such as those under
way in Manhattan-the Bank of America Tower, the Hearst Corporation
headquarters, The New York Times headquarters and Seven World Trade
Center-raise ambitious environmental expectations designers must
seek to fulfill. Can the projects meet these goals? The answer may
well depend on the assumptions underlying the approach to the projects'
design and construction.
Developers and designers are starting to understand that a holistic,
integrated approach to design and construction is necessary to meet
the goals of a new green building, or to transform a conventional
building into one greener in operation. Such an approach will optimize
the benefits of all of the building's systems and materials to provide
a healthy and efficient workplace. This means, among other things,
avoiding the temptation to rely on a single technology or a specific
product as the "magic-bullet" solution to challenging problems.
A case in point is the issue of indoor air quality. Buildings
face a number of threats to indoor air quality: overheating, poor
ventilation, out-gassing of building components and furnishings,
condensation and mold formation. Certainly building decision-makers
are correct to be concerned about the quality of indoor air and
the possibility that a building for which they are responsible might
be experiencing sick building syndrome. Sick building syndrome not
only threatens building occupants, but it can result in litigation
that threatens the bottom line of employers and building owners
alike. When addressing these challenges, how does an integrated
approach to maximizing indoor air quality differ from a single-source
solution?
Particularly in the case of building renovations, solutions to
indoor air quality problems are often thought to be achieved only
by spending generous amounts of money on bigger and better heating,
ventilation and air conditioning systems (HVAC) that are to be operated
at high intensities for increasingly long periods. According to
the conventional wisdom, more HVAC more often is the only solution
to improving indoor air quality. Research and experience suggest
that the problems common to sick building syndrome-poor ventilation,
off-gassing, condensation and mold formation-are all caused or made
worse by building heat.
Given the fact that building overheating has traditionally been
dealt with by air conditioning, it is easy to see why concerned
building managers of existing facilities and designers of new ones
can be seduced into believing that more HVAC more often is the magic
bullet solution to indoor air quality problems. Increasing building
ventilation might require upgrading existing HVAC capabilities.
Both upgraded and existing HVAC systems may have to be operated
at higher intensities more often than has traditionally been the
case. Of course, this will result in increased energy and operational
maintenance costs.
But more HVAC more often may actually be counterproductive. In
addition to increased cost, more HVAC more often will negatively
impact some building occupants who rightly or wrongly believe "conditioned"
air is less desirable to work in than non-conditioned air. Their
concerns are not unfounded. According to the Common Colds Centre,
Cardiff School of Biosciences at Cardiff University in the Britain,
air conditioning itself may contribute to infection with common
cold viruses, drying out the nose's mucus lining and thus weakening
the body's natural protection against infection and encouraging
virus proliferation. An internal study conducted by the ECOS Corporation,
an environmental consulting firm based in Sydney, Australia, found
that, "Intensive air conditioning all year long was identified as
having a strong negative impact on the quality of the office environment."
Additionally, anecdotal evidence suggests that air conditioning
can aggravate the effects of arthritis and neuritis and make people
sick due to the extreme variances between outdoor and indoor temperatures.
If HVAC were the only solution to indoor air quality problems,
building designers and managers would have to accept the increased
costs of upgrading and operating HVAC systems, and building occupants
would have to put up with the negative impacts of conditioned air
24-7. Fortunately, indoor air quality can be improved, not by replacing
HVAC use with another wonder technology, but by applying an integrated
solution. Heat-blocking applied window film or solar control glass
can significantly decrease the load on HVAC systems, creating an
integrated system to control temperature and improve indoor air
quality.
Unlike solid walls, windows and fixed glass transmit both heat
and light into a building's interior. According to the California
Energy Commission, 30 percent of a building's cooling requirements
is from heat entering through existing windows. As a supplement
to HVAC, stopping heat at the window using heat-blocking window
film can both reduce air conditioning operating frequency and cost,
and satisfy many building occupants who find "conditioned" air less
desirable.
Of course, the reduced load on HVAC systems results in energy-cost
savings. The most recent window film installation at Stanford University
took place at Encina Hall, originally constructed as a dorm in 1891
and completely renovated as an administration building in 1998.
In June 2003, 6,212 square feet of spectrally selective window film
was applied, blocking solar heat while simultaneously transmitting
high levels of natural light. As a result of the film's installation,
Encina Hall now enjoys an annual savings in air-conditioning cost
of nearly $5,000.
It should come as no surprise to observers of the natural world
that no single product or program component can be relied upon to
achieve sustainability goals. In that regard, window film can no
more do the job alone than can heavily burdened HVAC systems, which
historically have been expected to carry 100 percent of the responsibility
for maintaining a healthy indoor environment.
The best architects, designers and contractors are increasingly
pioneering holistic, integrated solutions. They know, and their
example will inform others, that the best results will be achieved
and maintained only when a multitude of systems function in an integrated
and orchestrated approach.
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