LEED Energy Performance Modeling and Evaluation of the S.T. Dana Building Renovations
The University of Michigan's S. T. Dana Building has upgraded its hundred year old infrastructure. The goal of the renovations was a building where the principles of environmental responsibility are not only taught, but upheld and demonstrated to the community. This project is part of a process toward obtaining LEEDTM certification for the S.T. Dana Building Phase II Renovations. The specific objective of this project is to evaluate energy use and the energy efficiency performance of these renovations for LEED credits in the Energy & Atmosphere category.
The LEED Rating system requires a building energy simulation to demonstrate the energy savings for a proposed project. This report describes the modeling methods and building characteristics and also provides detailed parameters for the simulation. The Phase II renovations are modeled with the eQUESTTM energy analysis software that uses the DOE-2.1 building energy simulation engine. A Base Case model of the Dana Building compliant with ASHRAE 90.1-1999 is developed using eQUESTTM which serves as a baseline reference that meets the minimum energy efficiency requirements for LEED certification. A Proposed Case model is developed from the Base Case model with changes that correspond to the efficiency measures implemented in the building renovations. One of the challenges was to model the radiant cooling panels that were added in the non-laboratory spaces in the ground floor through the third floor of the Dana Building. The radiant cooling panels are modeled as a fan-coil unit with infinite fan efficiency to simulate zone cooling, resulting in zero fan energy use.
The model demonstrated that energy savings in the Dana Building are primarily from use of Radiant Cooling Panels. There was a 12% savings in total regulated energy consumption (heating, cooling, fans and pumps, service hot water and interior lighting) and a 20% cost savings, which contributed four LEED credit points in the Energy and Atmosphere category. The renovations led to an annual savings of 279,000 kWh of electricity and 586 Mbtu of chilled water. This in turn saved $22,861 and $11,474 for electricity and chilled water, respectively, at the current utility rates. The steam usage increased slightly and cost an extra $1,739. A comparison between the total energy demand in Fiscal Year 2002-03 and the simulated Base and Proposed Models of the Dana Building is also made. Challenges in the modeling process are highlighted and directions for future research are discussed. A recommendation for future research includes the application of an uncertainty analysis to the building energy simulation for LEED credits in the Energy & Atmosphere category.