ENERGY EFFICIENCY
FAST FACTS
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Modern steel has rapidly become one of the most energy
efficient building materials to produce. Between the
early 1990s and 2007, the U.S steel industry cut
energy use per ton of steel by nearly 1/3.
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Cold-formed steel (CFS) buildings can be some of the
highest performing buildings. CFS buildings have been
built to Energy Star status, and can meet LEED
requirements and other green building programs and
standards.
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Whole building design of the energy package using
readily available simulation tools will enable code
compliant and cost-effective solutions to today's more
stringent energy codes.
With a few basics under your belt, you can build a steel
framed building that is as or more efficient than a
building constructed with competing materials. First,
keep in mind that all building materials transmit heat.
When placed in a wall or other part of a building, the
wood or steel studs, joists, trusses, concrete beams,
masonry block, brick, and even nails and screws provide
a pathway for heat transmission. In some cases, the
extra heat loss amounts to very little in terms of
actual energy use. In other cases, especially in colder
climates, it can be significant.
In order to
address unacceptable heat transmission though metal,
wood, or concrete, designers and building codes
frequently require a layer of continuous insulation,
usually a foam product, on the exterior of wall, floor,
or roof assemblies that are exposed to the exterior. For
any building, foam insulation adds costs, for example, a
1” layer of foam on a steel wall assembly can add as
much as $1/sf of wall area, or thousands of dollars to
even a small building.
The Steel Framing
Alliance has taken an approach to thermal performance of
steel framed buildings that includes research to improve
performance, development of design guides and other
tools, and a campaign to insure that current codes and
standards contain the best available information on the
performance of steel, have fair requirements that do not
favor one material over another, and provide maximum
flexibility for compliance. The approach encompasses the
following:
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Recognizing that the steel industry is innovative.
Numerous systems have been developed that effectively
eliminate or reduce thermal bridging through steel
members. Systems include steel panels imbedded into
foam insulation, “warm wall” designs where steel is
placed entirely inside the insulation layer, and cost
effective ways to use continuous foam insulation.
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Encouraging Steel Framing Alliance members to take
advantage of some cost effective methods to build a
higher performing building without necessarily adding
excessive amounts of foam insulation to the exterior.
Higher efficiency water heaters or heating and cooling
equipment, better windows, or more insulation
elsewhere are all options to explore.
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Encouraging steel framers and manufacturers to get
involved early with the designer or building owner to
insure a good performing building that does not
needlessly over burden the framing with excessive
costs for energy code compliance. The Steel Framing
Alliance Thermal Design Guide describes how to use a
building simulation or performance approach to getting
the most out of your design. However, this requires a
change in role of framers or steel manufacturers or
suppliers on the constructed project.They must be
willing to get much more involved in the upfront
design of the building.
ENERGY EFFICIENCY RESOURCES
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Thermal Design and Code Compliance for Cold-Formed
Steel Walls.
Download
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Improving Thermal Performance of Single Family Homes
in Hawaii through High Solar Reflectance Coatings on
Above Grade Walls. Also applicable to homes in other
locations of Climate Zone 1 and 2 of the International
Energy Conservation Code.
Download
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Training Session. Understand the IECC and how it
relates to steel framing. Although developed for
Hawaii with a focus on housing, this session provides
information applicable to all building types and
locations throughout the United States.
Download
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Siding attachment over foam insulation – research
report. SFA, with support from the New York State
Energy Research and Development Authority, sponsored
this testing and analysis program to provide solutions
for attaching siding and other cladding materials to
CFS walls when the energy code requires thick layers
of continuous insulation on the exterior of the
wall.
Download
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Assessment of commonly-used code compliance simulation
software relative to cold-formed steel framing.
Understanding software options will become more
important to the CFS industry as newer energy codes
are adopted in the coming years.
Download
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