Roundtable on Windows
Brendan O’Neill,
Posted
06/01/2010
MA:
Why should a metal building developer/contractor/specifier choose
one type of window over another?
Mary Olivier, Marketing & Client Services Manager,
Tubelite Inc.: It's a combination of several things:
aesthetics, functionality/need, performance, sustainability and
cost. All aspects need to be kept in mind during the design and
decision processes. Too often,selections are made based upon one or
two of these factors; typically with price being the overall
driver. Many times, in-depth analysis will prove that a higher
performing product, with a higher initial cost, will provide the
greatest value and savings in the long run. But the opposite also
can also be true. If performance is the sole focus, then the cost
may have an extremely extensive payback period. Upfront analysis of
all factors is key. This same philosophy should be used in
selecting the manufacturers, suppliers and installers.
Terry
Zeimetz, Terry Zeimetz, Commercial Marketing Manager, Pella
Corp.: I usually think of it in terms of six major areas
that someone might consider when determining what's the most
appropriate window system for their building: The first one is
aesthetics-the design; what does it look like and how does it
complement the building. Two might be energy efficiency and thermal
performance-how good of an insulator is it? The best would be wood,
fiberglass and vinyl, and the poorest would be aluminum, even with
thermal breaks.
The third major consideration is price-typically vinylis the least
expensive, then fiberglass, then wood, and aluminum is the most
expensive. The fourth one would be durability-how long is this
window going to last? The next one would be maintenance- how easy
is it to maintain the windows? Aluminum, fiberglass and vinyl are
extremely low-maintenance because there are no finishes to
maintain. The sixth major area to consider is sustainability-how
sustainable is the material, and what is the embodied energy of the
material [how much energy was required to manufacture the
product]?
MA: What are the newest innovations in windows for metal
buildings?
Olivier: The movement toward sustainability and energy
reduction continues to broaden in focus. Framing systems with
thermal barrier systems can contribute to these benefits,
especially in geographic areas that experience extreme heat or cold
temperatures. Low-E insulating glass, often filled with argon gas
between multiple layers of glass, is another example. Window
systems with thermochromic glass technology, which passively tints
when there is direct sunlight, blocks the sun's rays and lets users
enjoy the benefits of seeing out the window, while also providing
relief from sun's heat and glare. The best solution is a
combination of these various offerings, dependent upon factors such
as the building's geographic location, the direction the windows
are facing, the occupants' needs within the building, etc.
Zeimetz: The biggest thing you've got going on in the
aluminum [window] world is experimentation with the thermal breaks.
They know that the thermal breaks are the weakness in their
product. It works much better than the aluminum in resisting the
flow of heat, but it's not very good when compared to the other
materials.
Fiberglass is brand new and is probably the material on the cutting
edge of the latest technology and how you go about weaving together
the fiberglass mats, and the use of insulation within the frames of
the windows to further increase the energy efficiency of the frame.
Fiberglass is probably the area of greatest change.
MA: Where do the growth areas/markets for windows
lie?
Olivier: Operable windows appear to be a growth market
due to an increase in retrofit projects and a drive for natural
ventilation for occupant comfort and energy savings. Also,
daylighting optimization products and features are gaining
attention, such as sunshades, light shelves, glass coatings and
thermochromic glass. Blast mitigation products are of importance to
government and high-security applications,however, energy savings
also remains of high priority for all public facilities.
Zeimetz: The market opportunity is the lowest it's
been in decades, so most of the opportunity in terms of sales is
what's being driven by the stimulus funds through government
projects. There are a lot of things happening in military bases and
the [General Services Administration] and upgrading those
buildings. In a lot of cases, those buildings are requiring
products that are blast-resistant. That's probably where the
biggest opportunity is now-anything that's government funded,
including the housing authorities.
MA: Have codes and regulations had an effect on windows
for metal buildings? Will they in the near
future?
Olivier: These tend to conflict across the regulating
bodies. They are also often viewed as a whole, including both
residential and commercial buildings,when in actuality both have
very different needs. Accountability to achieve claimed energy
savings on LEED buildings has also increased.
Zeimetz: The biggest driver on windows, regardless of
the type of building, is the design for wind. It hasn't really
changed a lot through the decades, but you're calculating the
design pressure for the entire building and specific to the
windows. So as long as the windows can resist the code-required
design pressures, that's probably the biggest concern. Making sure
that the windows are structurally adequate, so that if there's a
90-mph wind, it doesn't blow the window into the building.
MA: What advancements or trends do you expect to see in
the windows market over the next 2 to 3 years?
Olivier: The continuing trend toward sustainability an
focus on the environment will drive demand from building owners for
products that offer recycled material content, as well as energy
savings. These trends will more than likely transition to
regulations and codes.
Zeimetz: I already mentioned the importance of thermal
breaks in aluminum windows. The other area of advancement would be
in glass. The Department of Energy R-5 program-where the government
is promoting the effort to get windows to be rated R-5 for the
insulating factor. I think there's been more than 50 companies that
have submitted products that are at least R-5. Of course, R-5 is
nothing compared to an R-19 wall, but with windows R-5 is pretty
good.
ONLINE EXCLUSIVE
Due to space constraints, some of the answers in this Roundtable
had to be edited. For the complete, unedited version, please visit
the Online Exclusive section of our website,
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