Turn off, save up:
Daylighting is a bright energy idea
Mike McLain,
Posted
10/01/2008
There sure is a
lot of talk about energy these days, and we have arrived at a
tipping point. Fossil fuels have been determined to be a finite
source of energy that will eventually run their course, while
global demand and consumption is increasing at an unparalleled
rate.
Energy has become a volatile commodity expanding well beyond the
historic notions of being inexpensive and in endless supply. We
have been teased in the past with short supplies and long lines at
the gas pumps, but this time it is different. This time, we all
have come to realize that the world has changed and solving our
energy needs requires action unlike anything we have done in the
past.
Much is being said about reducing dependency on foreign oil and
increasing domestic energy sources, but very little is being said
about conservation. Regardless, many people are making changes in
their personal habits to lead a more sustainable lifestyle. We are
driving less, looking for more fuel-efficient vehicles, changing
from incandescent to fluorescent bulbs, turning down the
thermostats, recycling, carpooling, using mass transit and
developing alternative fuels. Is it enough to make a difference? Is
it enough to make "the" difference?
Shifting
Ideas
We can make significant gains toward the goal of energy
independence without making tremendous sacrifices. It requires a
shift in our conventional wisdom so we can understand our
connection to every aspect of our environment. With that concept
comes a realization that form and function can be challenged in a
manner that alters the intrinsic value that many products and
service shave held over the years. Who would have thought a roof
plane could be a better window than a window itself when it comes
to transmitting and diffusing light into a structure?
Reducing the Load
One of my childhood memories is being told repeatedly to turn off
the lights when leaving a room. It certainly was not to conserve
electricity for the sake of the planet; it was to save a few
pennies here and there. That "golden rule" is more applicable now
than ever. What if we developed an adaptation of this rule, and
that upon entering a room, we did not turn on the lights?
Statistics clearly demonstrate the highest single use of energy in
our society is generating artificial light within our buildings.
What would happen to our energy consumption if we could turn the
lights off during the daylight hours of a typical work or school
day in our country?
America could
reduce its peak-load electrical demand by 24,000 megawatts just by
"daylighting" existing buildings with toplighting or skylights,
according to research by Jonathan McHugh, P.E., LC, technical
director with the energy consulting firm Heschong Mahone Group
Inc., Oakland, Calif. Not only that, this decrease could be done
for 1/20th the cost of photovoltaic solar panels.
Metal at the Forefront
For decades, metal building systems dominated a significant portion
of the nonresidential low-rise commercial and industrial building
market. This was the result of innovative approaches to the design,
detailing and manufacturing of these structures. These advantages
never really included the ability to daylight the interior as there
were two significant obstacles. One was that the material used for
skylight lenses typically consisted of reinforced fiberglass with
low transmittance and diffusion qualities.
Today, double-glazed skylights can provide up to 68 percent light
transmission with 100 percent diffusion, which is 50 percent more
visible light transmission compared to standard yellow fiberglass
panels. In addition, this new technology provides glare-free,
ultraviolet- damage-free and hot-spot-free natural light to
maximize the number of hours building owners or occupants can shut
off their lights and save energy.
The other obstacle
was that there was little interest in cutting holes through a
perfectly good roof. These issues are no longer obstacles as
skylight lenses and roof penetrations can be sealed effectively for
any climate conditions because of advances in sealants and curb
designs. Daylighting a metal building comes with less risk and
greater energy-saving benefits. Now more than ever metal building
systems can assume a leadership position with respect to energy
efficiency. Higher levels of insulation. in the roof and wall
assemblies, coupled with daylighting the spaces below, offer
tremendous savings and advantages. In fact, the new ASHRAE
90.1-2007 energy standard for the United States has been published
with an addendum "D" for daylighting, which states that building
designs utilizing high visible light transmission skylights with a
minimum diffusion of 90 percent-in combination with a daylighting
control system-can eliminate any solar heat gain coefficient from
the design. This is because high-performance daylighting generates
just half the heat buildup of the most efficient florescent
lighting system for the same lumen level. This means that you get
twice the light for the same amount of heat, or half the heat for
the same light, as the most efficient industrial lighting system on
the market.
Making the Difference
Research has determined that approximately 70 percent of the
electricity consumed within our country is associated with the
operation of existing nonresidential structures. Lighting is the
largest component of this consumption. Daylighting systems can be
installed just as easily in existing buildings as with new
construction. If we could daylight just half the existing space,
the impact will be significant. If we can reduce peak load
electrical demand by 12,000 megawatts, we would effectively
eliminate the need for 12 1,000-megawatt nuclear plants or 24
500-megawatt coal-fired plants. This action represents real change
and is within our reach.
High-performance prismatic skylights provide building owners, as
well as builders, architects, erectors and code officials, with
viable options and solutions to the energy crisis we face today and
in the future. Find out how we can help you turn the lights off and
conserve a significant amount of energy while improving the overall
quality of the environment both inside and outside your
buildings-all while taking advantage of the new-construction tax
incentives created by the Energy Policy Act of 2005. We can make a
difference- maybe even "the" difference-if we all pull
together.
Mike McLain is general manager of Bay Insulation Co., Green Bay,
Wis. For more information about Baylight powered by Sunoptics,
visit www.bayindustries.com.
www.bayindustries.com