 |
Over the last three centuries, advances in windows and glazing technologies
have spurred dramatic changes in the design, construction, and function
of buildings. Today's windows, doors, and skylights (also known
as "fenestration") contribute significantly to the total building
system. Through ongoing advances in R&D, tomorrow's windows
and glass can further enhance the comfort, safety, well-being, and
productivity of occupants; open the way to innovations in architecture
and construction; and increase the energy and environmental performance,
functionality, and longevity of buildings.
Improving the energy performance of windows is a primary focus
of DOE research. In the long term, this research targets the development
of window systems that are net energy contributors as opposed to
energy users. In the shorter term, significant savings can be realized
through incremental improvements in the energy efficiency of windows,
beyond today's ENERGY STAR®
standards.
Program Goals
Program goals for windows R&D are to develop and deploy high-performance
advanced window and glazing technologies, from component technologies
to fenestration products to whole-building integrated systems; and
to develop the performance metrics, tools, and knowledge base that
will motivate decision-makers to select high-performance products.
Conventional windows are the weak links in the building envelope.
Windows currently consume 3.8 quadrillion Btu of energy in the U.S.
annually in the form of heating and air conditioning loads, at a
cost of more than $30 billion. Yet ultimately, window systems have
the potential to outperform the best-insulated wall or roof in terms
of annual energy performance, peak demand reduction, and costs,
for any orientation or climate. Such high performance levels will
require advanced energy-efficient technologies that cut undesirable
thermal gains and losses through windows. Further, advanced technologies
will enable windows to capture and redirect more beneficial daylight,
reducing the need for electric lighting. In commercial buildings,
daylighting has the potential to reduce lighting loads by about
25%, saving 1 quadrillion Btu annually.
Taking all these capabilities into account, the long-term energy
target of DOE windows R&D is to save over 4 quadrillion Btu
of energy annually in U.S. buildings, by reducing heating, cooling,
and lighting loads. This savings is the equivalent of 2 million
barrels of oil per day. Achieving the long-term target will require
aggressive R&D efforts, coupled with voluntary and mandatory
deployment efforts at national, regional, and local levels.
Strategy
DOE windows R&D activities reflect the priorities defined
in the Window
Industry Technology Roadmap (PDF 859 KB), as well as the priorities
of DOE, which include a focus on reducing peak load requirements.
An ongoing web site, Envelope
& Windows Forum allows interested stakeholders to share
their views and stay updated on the latest R&D activities.
The program is intended to catalyze private investments in energy
efficiency by reducing uncertainty and risk, and to address high-risk
activities that are unlikely to attract private investments. It
also includes strategies to drive the marketplace toward more widespread
use of advanced technologies, by creating an accurate and unbiased
information base for decision-makers, providing technical underpinnings
for the development of standards, and supporting voluntary programs
to encourage use of more effective window systems. Activities are
highly leveraged by partnerships with the fenestration industry,
government laboratories, universities, utilities, and consumer groups,
as well as other relevant DOE programs.
The program addresses two closely linked areas of research:
Overall, the program is designed to provide:
- Impartial expertise to ensure optimum application of manufacturing
processes for efficient windows, in which the U.S. window industry
already has invested billions of dollars
- High-risk, government-supported research and development, required
to demonstrate the viability of advanced window technologies and
to optimally integrate them within total building systems
- Laboratory and field demonstration of the effectiveness of new
technology
- Increased understanding of the science behind heat transfer
and optics of windows
- Understanding of how occupants respond to new technologies for
a range of products and building applications, including impacts
on occupant productivity
- Development and validation of state-of-the-art computer tools
for product design and ratings
- Accurate tools for window design and selection
- Expert recommendations on window products as parts of whole
buildings for homeowners, builders, architects, engineers, and
specifiers.
Potential cost and energy savings are substantial. DOE-sponsored
research already has yielded major contributions to improving window
energy efficiency over the past two decades, as documented in a
recent report by the National Academy of Sciences on the economic
benefits of energy efficiency R&D. Advances in one area alone
— low-e coatings for windows — are estimated to have saved
the country over $8 billion, an amount far exceeding the cumulative
R&D investment in all DOE buildings technology R&D.
|
