Dean Heerwagen Archives - Research Portal

Occupant Perceptions of an Indoor Thermal Environment in a Naturally Ventilated Building

Ilyas, Salman; Emery, Ashley; Heerwagen, Judith; Heerwagen, Dean. (2012). Occupant Perceptions of an Indoor Thermal Environment in a Naturally Ventilated Building. Ashrae Transactions, 118(2), 114 – 121.

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Abstract

A strong emphasis is currently being placed on the use of natural ventilation as a means for providing a safe and healthful indoor environment as part of green building programs. There has been an increasing interest in developing natural ventilation design strategies that can furnish adequate fresh air to the building interior and simultaneously control the indoor air quality effectively, while providing significant energy savings. In naturally ventilated spaces, furnishing a suitable air exchange rate between the building exterior and interior can create a thermally comfortable and healthy indoor environment. However, the air exchange must occur such that the indoor air quality of the building is not compromised and thermally comfortable conditions for the occupants can be maintained. Architecture Hall is a recently renovated, naturally ventilated building located on the University of Washington campus in Seattle. The natural ventilation in this building was evaluated using a variety of experimental techniques, which included measurement of carbon dioxide (CO2) levels, air exchange rates and air velocities. High CO2 concentrations are a good indicator of inadequate ventilation rates and poor air movement in a space. Hence, a number of standards and certification programs specify the use of outdoor air monitoring based on CO2 concentrations in an occupied space. Occupant surveys, based on a U.S. EPA study, were also administered to understand and analyse occupant perceptions about the indoor thermal environment and to identify the prevalence of any building related illness symptoms. The discussion in this paper will focus on the findings of the occupant surveys and how they relate to the measured CO2 levels, air exchange rates and air velocities in the naturally ventilated spaces. The natural ventilation function in Architecture Hall is largely climate driven. For the period of November through March particularly, outside temperatures are quite low and windows are seldom opened by the occupants, in spite of a large number of occupants being dissatisfied with the indoor environmental quality. Consequently, CO2 concentrations consistently exceed acceptable levels and very little air movement is recorded. [ABSTRACT FROM AUTHOR]; Copyright of ASHRAE Transactions is the property of ASHRAE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Keywords

Thermal Comfort; Natural Ventilation; Energy Consumption Of Buildings; Indoor Air Quality; Heat Exchangers; Carbon Dioxide

PhD in the Built Environment

The College of Built Environments consists of five departments that together provide one of the country’s few comprehensive built environment programs within one academic unit: Architecture, Construction Management, Landscape Architecture, Real Estate, and Urban Design and Planning. Together, this combination of departments enable faculty and students to engage almost the entire development process, from economic and environmental planning, real estate, regulatory processes, siting and design, through actual financing and construction, to facility management and adaptive reuse in subsequent stages. Thus, the college is inherently multi-disciplinary, not only in terms of the dimensions of reality that it treats, but also in regard to the specialized disciplines, methods, and practices that it employs: history, theory, cultural criticism, engineering, design, planning, urban design, energy sciences, acoustics, lighting, environmental psychology, ecology, real estate analysis, statistics, management, horticulture, soil science, law, public policy, and ethics. In addition, because of the College’s focus on comprehensive analysis and practice concerning the built environment and its interrelation with society, it is substantially engaged in interdisciplinary work with other units on campus and outside of the campus, including mechanical, civil, and electrical engineering; with public policy and the health sciences; with art and art history; with textual interpretation in the humanities; with many of the computing and digitization activities that range from digital arts to the information school and technical communications; with education and social studies and services; with sustainability and ecological programs, including urban ecology, geography, the College of Forest Resources (especially urban horticulture and urban forestry), and Ocean Science and Fisheries; with environmental and land use law.

The College’s interdisciplinary character is a good fit with the emerging trends in today’s complex world, where only a pluralistic and collaborative approach will generate the necessary learning and teaching, research, and service. If we are to provide, in the end, both disciplinary and professional means to promote environmental well-being, the diverse environmental specializations must be fully integrated. Thus, working outside traditional disciplinary and departmental categories, the College’s faculty will advance solutions to problems that demand interdisciplinary perspectives and expertise. Other UW units bring much to bear on the built environment and students are wholeheartedly encouraged to explore possible cross-campus connections both in obvious and seemingly unlikely places. The Technology and Project Design/Delivery specialization especially connects with Psychology, the Information School, Technical Communication, Computer Science and Engineering, and Industrial Engineering; the Sustainable Systems and Prototypes field with Civil Engineering, Electrical Engineering, Industrial Engineering, Mechanical Engineering, the Information School, Technical Communication, the College of Forest Resources (especially Eco-System Science and Conservation, Urban Horticulture and Urban Forestry), the Evans School of Public Affairs, Geography, Public Health, Ocean Science and Fisheries, and Social Work, Urban Ecology, and perhaps Advanced Materials and Manufacturing Processes and Nanotechnology; the area of History, Theory, and Representation with Textual Studies, Art History, Interdisciplinary Arts & Sciences at Tacoma, and Comparative History of Ideas.

Dean Heerwagen

Heerwagen’s abiding intellectual and professional interest is the identification of how buildings can be created to serve the occupants who will live and work within them. Thus, the principal goal of his work has been to characterize, first, the range and natures of activities which occupants wish or need to accomplish in buildings and, second, the types of services which should be present in buildings (i.e., to enable occupants to perform these activities). These services include, generally, means for ensuring the health and safety of building occupants, as well as means for supporting other human physical, physiological, and perceptual psychological requirements.

Throughout his teaching and research he has sought to acquire and communicate knowledge about how to design and construct buildings so that occupants have settings that satisfy these requirements. In his teaching, research, and writing he has concentrated on how the presences of heat, light, sound, and good air quality in buildings can be controlled so that occupants can be assured comfortable environments which operate efficiently. In his work he seeks to examine and describe how to create buildings whose internal environments are well-conditioned (i.e., to suit occupants’ needs and wishes). Basic examples of what he addresses include how to establish buildings that are thermally comfortable, well-daylighted, suitably quiet (while also enabling good communication by speech and music), and adequately ventilated. Necessarily, achievement of these performance attributes can rely, for instance, on various active control systems (e.g., mechanical and electrical systems) or on passive devices.