Maximizing Indoor Air Quality and Thermal Comfort in Naturally-Ventilated Education Buildings
Advisor: Professor Khaled El-Rayes
ABSTRACT
Education buildings in the United States are a critical part of the nation's infrastructure, serving 29% of the US population who spend a major part of their daytime indoors. These buildings represent 14% of the total commercial floor space and are the third major consumer of energy. Furthermore, the majority of these education buildings are aging, with 61% built before 1990, and they often suffer from poor ventilation and antiquated heating systems. These conditions of poor indoor air quality (IAQ) and thermal discomfort have been reported to negatively impact the health, wellbeing, and academic performance of students and faculty. Accordingly, building owners and designers need to carefully analyze and optimize the design of these buildings in order to maximize indoor air quality and thermal comfort while minimizing construction costs.
The main goal of this research study is to develop novel models for optimizing the design of naturally-ventilated education buildings that provide the capability of maximizing indoor air quality and occupant thermal comfort while minimizing construction cost. To accomplish this goal, the research objectives of this study are to develop: (1) a novel multi-objective optimization model for generating optimal tradeoffs between maximizing indoor air quality in naturally-ventilated classrooms and minimizing their construction cost; (2) an innovative multi-objective optimization model for optimizing the building envelope design to maximize the thermal comfort of its occupants while minimizing its initial cost; and (3) an original multi-objective occupant comfort model that is capable of generating optimal tradeoffs between maximizing weighted indoor air quality, maximizing weighted thermal comfort, and minimizing building envelope cost.
The performance of the developed optimization models was analyzed and verified using case studies of naturally-ventilated education buildings. The results of this analysis illustrated the original contributions of the developed models and their novel methodologies for (i) generating optimal tradeoffs between classroom air quality and related construction cost; (ii) quantifying and optimizing classroom thermal comfort using the ASHRAE Adaptive Model; (iii) accounting for varying occupant loads across different building spaces using original weighted metrics for indoor air quality and thermal comfort; and (iv) maximizing weighted indoor air quality and weighted thermal comfort while minimizing envelope cost. These novel and unique capabilities are expected to support building designers in their ongoing efforts to enhance the indoor air quality of learning spaces, improve the thermal comfort of building occupants, and reduce the construction cost of education buildings. These improved learning environments will positively impact the academic performance, health, and well-being of students, faculty, and staff.