Energy Consumption Analysis & Proposed Retrofit of a Duke University Dormitory

by Nadim Atalla, Emilia Chojkiewicz, Chris Jernigan, Nicolas Kardous, Brigitte von Oppenfeld, and Cassie Yuan
Mar 04, 2019chevron-down
7 Contributors
Energy Consumption Analysis & Proposed Retrofit of a Duke University Dormitory
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Energy Consumption Analysis & Proposed Retrofit of a Duke University Dormitory

Ecodorm

  • Nadim Atalla, Trinity ’17

  • Emilia Chojkiewicz, Pratt '19

  • Chris Jernigan, Trinity ’17

  • Nicolas Kardous, Pratt ‘19

  • Brigitte von Oppenfeld, Pratt '17

  • Cassie Yuan, Trinity ‘17

Faculty Mentor: Emily M. Klein, Earth & Ocean Sciences

Editor’s Note: This research originated with the Bass Connections team, Energy and the Environment: Design and Innovation (2016-2017). Bass Connections project teams bring together faculty, postdocs, graduate students, undergraduates and external partners to tackle complex societal challenges in interdisciplinary research teams.


Abstract

To investigate the incorporation of green building concepts into college dormitories, we examined the current state of energy consumption in a Duke University dormitory. Our focus was Gilbert-Addoms (GA), a 60 year old, 68,625 square foot building. To mediate inefficient fenestration, window parameters were measured, heat transfer models were developed using principles of physics and thermodynamics, and a thin film and sealant retrofits were proposed and analyzed by the same models. Next, to incorporate renewable energy, solar heat gain was calculated from historic solar resource data, and a solar photovoltaic/thermal hybrid system was proposed. Retrofit variables were plugged into the model, and compared with the building’s past energy consumption data. The results proved cost-effective in the long term while simultaneously reducing greenhouse gas emissions, demonstrating that retrofits offer feasible potential as Duke and other universities pursue future sustainability goals.


Research Reflection

Sustainable design poses a challenging paradox: how does an engineer design a building that is both energy efficient and user-friendly? For example, despite the aesthetic and practical benefits, windows and doors are openings in a building that increase the structure’s exchange with outside air and therefore, contribute to its heat loss and energy inefficiency. To resolve the conflict between glass’s potential to improve user experience and its vulnerability in insulation, we modeled the effect of implementing 1. two retrofit measures on windows and 2. a photovoltaic thermal (PV/T) hybrid solar system into the building’s electricity provision. The subject was Gilbert-Addoms, a 68,625 gross square foot (6,475.5 square meter) dormitory on Duke University’s East Campus that first opened in 1957 and renovated in 2014. Our overall analysis aimed to pioneer retrofit strategies to improve existing buildings’ energy efficiency while maintaining the present high quality of life for first-year students residing in the dorm. In addition to making potential modifications on aged structures, these strategies are applicable to on-going construction on Duke campus and have valuable implications on future designs.

The goal of this project was to design a feasible energy efficiency retrofit for the Gilbert-Addoms dormitory focusing specifically on reducing the energy waste during the summer months. Although the building was left mostly uninhabited during the summer, it needed to remain below a certain threshold temperature to avoid decay; therefore, the energy waste due to cooling was excessive. Focusing on this specific issue, we came up with two simple retrofit measures: installing films/sealants on the windows of the building, and solar panels on the roof. The fenestration modifications would reduce both the heat gain due to irradiance through the glass and the heat loss due to airflow through small holes in the window sealing, i.e. improve the building’s energy efficiency through insulation approach. The solar system would power the air conditioning in a sustainable manner. Our models demonstrated that the fenestration changes would be the most cost-effective. While solar retrofit would save more energy in the long term, its return on investment is slower; more details can be found in the results section of our report.

In the tackling of this project, our team faced many questions and challenges; for example, we did not all have the thermodynamics knowledge to model heat loss. Over the course of the year, however, we not only gained new analysis techniques and practical experience in the energy field, but we also all grew intellectually and interpersonally.

Specifically, familiarity with weather data is extremely useful for the solar field, as it can be used to calculate and model aspects of the solar system such as monthly production and temperature losses. In addition, using the National Renewable Energy Laboratory’s (NREL) System Advisor Model (SAM) to perform these calculations was an invaluable experience, as many companies in the solar industry use this very same software in their predictive analyses. With our new tools, we were able to use the weather data to calculate the heat gain into the building over the course of the summer in a novel way. To supplement the software models, our group also used a physical model to calculate heat loss through the small holes in the window sealant. This physical modeling gave us experience making realistic assumptions and creatively devising a method for transforming a real world situation into a set of equations. To look at the realistic applicability and cost-effectiveness of our retrofit, we incorporated financial modeling to find the payback time of our retrofit.

Furthermore, the experience imparted skills and knowledge utilized well beyond the 2016-2017 course. A few of us persist as engineering undergraduates; a few of us are pursuing STEM graduate programs; and a few of us now work in the solar energy and environmental remediation industries. Despite our different paths, we all agree that working together to design an innovative, eco-friendly, and financially feasible Eco-Dorm retrofit has proved rewarding and worthwhile.

After finishing our Eco-Dorm design, we were proud of our hard work, especially because we felt it could have a positive real-world impact. College campuses are abuzz with creativity, innovation, and activism, which made Duke the perfect focus of our work. Our team sees the potential for our design concepts to actually be implemented on a college campus. While the design itself makes many simplifying assumptions, it presents a detailed cost and energy analysis of improving the building’s fenestration and tapping into its solar potential. This analysis has the potential to be implemented by HDRL as they were given access to our report and results at the end of our project. Our hope is that Duke’s administration will take the initiative to conduct eco-friendly renovations on campus buildings in the near future and keep moving swiftly on the path to carbon neutrality.


Report


Contributors
N
Nadim Atalla
E
Emilia Chojkiewicz
C
Chris Jernigan
N
Nicolas Kardous
B
Brigitte von Oppenfeld
C
Cassie Yuan
E
Emily M. Klein
Roles: Faculty Mentor