The United States Department of Energy reports that forty percent of all energy consumed in the nation is consumed by buildings. A renewed focus on high performance buildings at the Georgia Tech College of Architecture aims to reduce that percentage and meet the rising demand for in-house talent to evaluate the environmental impact of design decisions. Continuing a twenty-five-year trajectory of research leadership, Tech students and faculty are leading the way in digital design, building simulation and architecture/engineering/construction integration.

The High Performance Buildings PhD concentration and Post-Professional Master of Science program are developing new knowledge and new tools to inform design and investment decisions. “We are focusing on quantitative expressions of energy performance,” said Professor Fried Augenbroe in a recent Research Forum, hosted monthly by the College of Architecture. “Our partners can integrate these measures in the development of innovative architectural designs, and streamline the energy saving discussion within the design.” Augenbroe says current methods cannot predict performance with certainty, hence the need for research that shows performance risks to developers and owners. This will lead the way to new energy-saving approaches with the upfront involvement of all stakeholders including the occupants.

Associate Dean for Research Steve French has already recognized Georgia Tech’s potential to lead nationally in this area. “These topics that are central to the College of Architecture are currently at the forefront of the research agenda of the nation and the Institute,” he said.

The energy performance standard for Qatar
Recently, researchers at Georgia Tech participated in the development of an integral sustainability assessment system for the middle-eastern country of Qatar led by the TC Chan Center at the University of Pennsylvania. The approach provides a more transparent and locally adapted alternative to for instance LEED. The TC Chan center is led by Dr. Ali Malkawi, one of the first PhD graduates in building technology from Georgia Tech’s College of Architecture.

Called the Qatar Sustainability Assessment System (QSAS), the standard has distinct advantages in terms of transparency and robustness. The Georgia Tech team focused on the development of the energy performance criterion “The QSAS energy performance calculation is totally normative, which means that there is no wiggle room in its evaluation,” said Augenbroe. “The building either passes or it does not.” The Qatar construction market is about to adopt the method for country-wide energy performance rating and overall sustainability scoring, effective end of 2009.

The standard follows the CEN-ISO approach, as defined by the European Committee for Standardization (CEN), and the International Organization for Standardization (ISO). The standard defines energy outcomes on five levels: (1) thermal energy needs, (2) delivered energy, (3) primary energy, (4) CO2 emissions, and (5) NOx and SOx emissions. The CEN-ISO approach is very different from the ASHRAE 90.1 and IECC (International Energy Conservation Code) approaches which govern the US market.

To prepare market introduction, TC Chan researchers, including professor Augenbroe and his students have been running a series of energy standard workshops in Doha, the capital of Qatar.

The economic viability of a zero-energy solar house
Georgia Tech’s entry to the 2007 Solar Decathlon House gave the High Performance Building group a working prototype to study the economic viability of such a building. Recent doctoral graduate Huafen Hu focused on the question, “What would happen if it were mass produced today?” Hu performed a reliability analysis to quantify the underlying risks in terms of power unavailability and the “damage” this poses to occupants. The outcomes translate to a trade-off between investment costs and risk, thereby offering the ability to inspect the economic viability of large scale introduction of zero energy solar houses.

Recently the Georgia Tech Solar Decathlon House moved to the new Tellus Northwest Georgia Science Museum in Cartersville, Georgia. Tellus became the new home with the help of Green Habitats, Inc., an organization that promotes sustainable building by supporting research and educational programs to design and build housing that conserves water and energy.

Ongoing research into the practical application of PV at the residential scale is using Tech’s Solar Decathlon house as a test-bed, to test the feasibility of using captured rainwater for supplemental cooling of PV systems--thus increasing their efficiency. This research is being led by Profesors Augenbroe and Gentry in collaboration with Miroslav Begovic in the Georgia Tech School of Electrical Engineering and Huafen Hu of Portland State University.

Global leadership in simulation
MS and Ph.D. students in the High Performance Buildings program of the College of Architecture recently won an international simulation competition to devise a control system for a three-story, open plan office building located in Glasgow, Scotland. The competition was hosted by the England Chapter of the International Building Performance Simulation Association (IBPSA) at its annual conference.

Their winning entry looked at optimizing solar-assisted natural ventilation with a controlled hybrid ventilation strategy. Using readily available simulation tools, the proposal explored different combinations of inlet and outlet openings to maximize natural ventilation and to meet required levels of fresh air. Additionally, the proposal minimized energy consumption by using only mechanical heating and controlling the building inlets based on set temperature.

Most of the approaches and tools addressed above are part of the new MS HPB curriculum--led by Professors Augenbroe, and Russell Gentry along with Minjung Maing and Jason Brown. Minjung Maing has joined the Architecture faculty in a visiting role, adding extensive practical experience to the HPB Masters program in the technical design, realization and forensics of building enclosures.

Through his national and international engagements, Augenbroe is evangelizing the broad adoption of risk analysis in building performance simulation. One of the issues that his research team encounters is the fact that many malfunctions of building systems cannot be foreseen with our current simulations. This is one of the reasons why his group is focusing on building new simulation models with Modelica--a next generation systems modeling tool--to track potential anomalies in system behavior. The outcomes of this research will help the market to build more resilient HVAC and control systems. PhD student Jason Brown is graduating this spring on a Modelica model of the complex interaction between air flows inside buildings and thermal enclosure properties.

Whole-Building Life Cycle Assessment
Associate Professor Russell Gentry and Charlene Bayer in GTRI are leading a multi-disciplinary team with the American Institute of Architects to explore the future of Life Cycle Assessment in building design and construction. In the future, LCA will help architects identify which building components cause the most environmental impact, and whether the overall impact of a project comes primarily from site selection or ongoing operation of the building. Through this project the AIA will provide LCA resources for practitioners. The project also will outline ongoing efforts to improve whole-building LCA tools and will provide a vision for the use of LCA in the future.