Natural Comfort – a new early stage design tool


BSEG has released publicly Natural Comfort, a new early stage tool that provides design guidance for improving comfort in passive, naturally ventilated commercial buildings in warm and hot climates. The program and the research to develop it are the result of a unique collaboration between members of BSEG and researchers at LabEEE at the Federal University of Santa Catarina in Brazil, through the Fulbright grant research of Adams Rackes.

Natural Comfort estimates the fraction of occupied hours a building is likely to remain comfortable, and also provides precision intervals for the estimate. Comfort is determined by the adaptive model (80% acceptability) of ASHRAE 55-2013, and the tool is appropriate for small to medium commercial buildings in climates that have little to no daytime heating demand (i.e., no central heating system), which includes most of the tropics. Designed to be easy to use, Natural Comfort is implemented as a simple Python routine and requires 38 input parameters, nine of which an included utility program can determine from an .EPW weather file.

The development of Natural Comfort, which is based on support vector regression of ~50,000 EnergyPlus simulations, is described in detail in “Naturally comfortable and sustainable: informed design guidance and performance labeling for passive commercial buildings in hot climates” (Applied Energy, 2016) by Adams Rackes, Ana Paula Melo, and Roberto Lamberts. A case study included in the article demonstrates that modifying a small set of parameters can drastically improve thermal performance and achieve sustainable comfort in hot and warm climates. Natural Comfort is distributed freely for researchers and practitioners to use for quickly assessing and expanding passive comfort opportunities through simple, cost-effective design modifications.

The program can be downloaded directly here or at Research Gate. A full User’s Guide is included to explain how the program works, provide guidance on inputs, and give suggestions for parameters to prioritize based on sensitivity analysis.

Graduate Student Opening – Michael Waring

A Research Assistantship is available for an MS or PhD level student starting in September 2013 to work in the area of indoor air quality (IAQ) and building energy efficiency. Research focuses on characterizing and measuring IAQ and on integrated approaches for modeling and efficiently controlling IAQ and energy in commercial buildings. Responsibilities will include working with others to develop models, perform simulations, analyze data, and conduct lab testing and field implementation. U.S. citizens or permanent residents are strongly encouraged to apply. A Bachelors or Masters degree in Mechanical Engineering, Architectural Engineering, Environmental Engineering, or Electrical Engineering is preferred. Previous programming experience is also strongly preferred.

Please contact:

Dr. Michael Waring

Email: msw59 [at] drexel [dot] edu

Adams Rackes

Adams Rackes

Adams Rackes is a Ph.D. candidate in Architectural Engineering who investigates computational tools for improving the design and operation of sustainable buildings. His current research focuses on using machine learning and optimization techniques to enable smarter ventilation control in commercial buildings, in order to both save energy and improve indoor air quality. This work combines many of his interests, including energy efficiency of buildings, indoor air processes and impacts, simulation and modeling, building mechanical systems and automation, and optimal estimation and control. He has also worked on designing intelligent networks for indoor air monitoring with low-cost sensors; assessing ventilation strategy impacts on health, economic, and energy endpoints; and statistically characterizing physical, thermal, and indoor air parameters in the built environment. Most recently, he received a Fulbright grant to conduct a year of research in Brazil, to better understand what combinations of building parameters can enable passive, naturally ventilated buildings to remain comfortable in hot climates. Natural Comfort, a publicly available early stage design tool, was a result of that research.

Adams is a 2014 NSF Graduate Research Fellow and has also received an ASHRAE Grant-in-Aid. He received M.S. and B.S. degrees from Drexel, both in Architectural Engineering, in 2014 and 2012, and is an Engineer-in-Training. He also holds a B.A. in History and Literature from Harvard University, and formerly worked as a welder. He lives in Philadelphia with his wife and son.

Journal Publications

Rackes, A., Melo, A.P., & Lamberts, R. (2016). Naturally comfortable and sustainable: informed design guidance and performance labeling for passive commercial buildings in hot climates. Applied Energy, 174, 256–274.

Rackes, A., & Waring, M.S. (2016). Do time-averaged, whole-building, effective volatile organic compound (VOC) emissions depend on the air exchange rate? A statistical analysis of trends for 46 VOCs in U.S. offices. Indoor Air, 26, 642-659.

Hamilton, M., Rackes, A., Gurian, P. L., & Waring, M.S. (2016). Perceptions in the U.S. building industry of the benefits and costs of improving indoor air quality. Indoor Air, 26, 318–330.

Li, X., Tan, H., & Rackes, A. (2015). Carbon footprint analysis of student behavior for a sustainable university campus in China. Journal of Cleaner Production, 106, 97–108.

Rackes, A., & Waring, M.S. (2014). Using multiobjective optimizations to discover dynamic building ventilation strategies that can improve indoor air quality and reduce energy use. Energy and Buildings, 75, 272–280.

Rackes, A., & Waring, M.S. (2013). Modeling impacts of dynamic ventilation strategies on indoor air quality of offices in six US cities. Building and Environment, 60, 243-253.

Conference Presentations

Rackes, A., Ben-David, T., & Waring, M.S. (2016, September). Toward making ventilation decisions based on expected outcomes: A flexible multi-criteria framework. Paper presented at ASHRAE/AIVC IAQ 2016, Alexandria, VA, USA.

Rackes, A., & Waring, M.S. (2016, September). Spatial resolution and sensor accuracy in routine indoor air quality monitoring networks: are more sensors better? Paper presented at ASHRAE/AIVC IAQ 2016, Alexandria, VA, USA.

Rackes, A., Hamilton, M., Gurian, P., & Waring, M.S. (2016, July). Do building industry professionals and stakeholders believe what IAQ experts think is true? Paper presented at Indoor Air 2016, Ghent, Belgium.

Rackes, A., Ben-David, T., & Waring, M.S. (2016, July). An integrated utility maximization approach to next-generation commercial building ventilation. Paper presented at Indoor Air 2016, Ghent, Belgium.

Rackes, A., da Fonseca, R.W., Beck, E.O., Scalco, V.A., Palladini, G.D., & Lamberts, R. (2015, October). Avaliação do potencial de conforto térmico em escolas naturalmente ventiladas. Paper presented at the Encontro Nacional de Conforto no Ambiente Construído (ENCAC) 2015, Campinas, Brazil.

Hamilton M., Rackes A., Gurian P.L., & Waring M.S. (2015, December). Mental models of indoor air quality: does anybody believe the research? Poster presented at Society for Risk Analysis Annual Meeting, Arlington, VA.

Rackes, A., Ben-David, T., & Waring, M.S. (2014, July). Statistical models of whole-building volatile organic compound emission rates in U.S. offices. Paper presented at Indoor Air 2014, Hong Kong, China.

Rackes, A., & Waring, M.S. (2013, October). Advanced integrated indoor air quality and thermal air movement strategies. Paper presented at ASHRAE IAQ 2013, Vancouver, Canada.

Rackes, A., & Waring, M.S. (2012, July). Modeling impacts of dynamic ventilation strategies on indoor air quality over the United States office sector. Paper presented at Healthy Buildings 2012, Brisbane, Australia.

Email: aer37 [at] drexel [dot] edu
Research Gate
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