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Being located in subtropical area, the weather in Taiwan is hot and humid which imposing huge cooling load on buildings. Conventionally, central air-conditioning plants were designed using refrigerant compressors to make chilled water, and then pumped through the zone pumps to meet the cooling load, providing air-conditioning by Fan Coil Unit (FCU) or Air-Handling Units (AHU) by ductwork. To meet the varying cooling demand, two important systems were developed for energy savings, namely, the Variable Water Volume (VWV) system, and the Variable Air Volume (VAV) system, which has been widely adapted in Taiwan area. The working principle is mainly devoted to adjusting the volume of the chilled water and/or air volume delivered through inverter-driven pimps and fans to achieve energy saving. On the other hand, recently in Japan, an important energy-saving air-conditioning system has been developed which directly varying the refrigerant flow rate to meet the varying cooling demand by inverter-driven compressors, named VRV system. Comparative to the conventional air-conditioning system, the heat exchange mechanism of the VRV system has been effectively enhanced by direct exchange of the refrigerant and the cool air, which is in effect a combination of the VWV and VAV system. It provided huge energy saving potential for the application on buildings with moderate cooling loads, such as 100 USRT or so. It is the goal of this research project, to evaluate the performance of the VRV system in Taiwan¡¦s hot and humid climate, by performing full-scale experimental investigation so that energy savings effect can be validated quantitatively. Since VRV system is fairly new in Taiwan, the validation of the system performance under local weather condition is of particular importance. It is anticipated that through the changing of the operation conditions, such as different outdoor conditions, various partial load conditions, and different scheduling of the VRV system, the power consumption of the VRV vs. conventional system can be compared precisely and quantitatively. These experimental data will, in turn, provides valuable reference to the establishment of the building energy consumption index in Taiwan, which outwits the direct adoption of the foreign data such as from Japan, in achieving a much reliable database.

abstract: Dwindling energy resources and associated environmental costs have resulted in a serious need to design and construct energy efficient buildings. One of the strategies to develop energy efficient structural materials is through the incorporation of phase change materials (PCM) in the host matrix. This research work presents details of a finite element-based framework that is used to study the thermal performance of structural precast concrete wall elements with and without a layer of phase change material. The simulation platform developed can be implemented for a wide variety of input parameters. In this study, two different locations in the continental United States, representing different ambient temperature conditions (corresponding to hot, cold and typical days of the year) are studied. Two different types of concrete - normal weight and lightweight, different PCM types, gypsum wallboard's with varying PCM percentages and different PCM layer thicknesses are also considered with an aim of understanding the energy flow across the wall member. Effect of changing PCM location and prolonged thermal loading are also studied. The temperature of the inside face of the wall and energy flow through the inside face of the wall, which determines the indoor HVAC energy consumption are used as the defining parameters. An ad-hoc optimization scheme is also implemented where the PCM thickness is fixed but its location and properties are varied. Numerical results show that energy savings are possible with small changes in baseline values, facilitating appropriate material design for desired characteristics. / Dissertation/Thesis / M.S. Civil Engineering 2012

A very economical way of reducing the operational energy consumed by large commercial buildings such as an airport terminal is the automatic control of its active energy systems. Such control can adjust the indoor environment systems setpoints to satisfy comfort during occupancy or when unoccupied, initiate energy conservation setpoints and if necessary, shut down part of the building systems. Adjusting energy control setpoints manually in large commercial buildings can be a nightmare for facility managers. Incidentally for such buildings, occupancy based control strategies are not achieved through the use of conventional controllers alone. This research, therefore, investigated the potential of using a high-level control system in airport terminal building. The study presents the evolution of a novel fuzzy rule-based supervisory controller, which intelligently establishes comfort setpoints based on flow of passenger through the airport as well as variable external environmental conditions. The inputs to the supervisory controller include: the time schedule of the arriving and departing passenger planes; the expected number of passengers; zone daylight illuminance levels; and external temperature. The outputs from the supervisory controller are the low-level controllers internal setpoint profile for thermal comfort, visual comfort and indoor air quality. Specifically, this thesis makes contribution to knowledge in the following ways: It utilised artificial intelligence to develop a novel fuzzy rule-based, energy-saving supervisory controller that is able to establish acceptable indoor environmental quality for airport terminals based on occupancy schedules and ambient conditions. It presents a unique methodology of designing a supervisory controller using expert knowledge of an airport s indoor environment systems through MATLAB/Simulink platform with the controller s performance evaluated in both MATLAB and EnergyPlus simulation engine. Using energy conservation strategies (setbacks and switch-offs), the pro-posed supervisory control system was shown to be capable of reducing the energy consumed in the Manchester Airport terminal building by up to 40-50% in winter and by 21-27% in summer. It demonstrates that if a 45 minutes passenger processing time is aimed for instead of the 60 minutes standard time suggested by ICAO, energy consumption is significantly reduced (with less carbon emission) in winter particularly. The potential of the fuzzy rule-based supervisory controller to optimise comfort with minimal energy based on variation in occupancy and external conditions was demonstrated through this research. The systematic approach adopted, including the use of artificial intelligence to design supervisory controllers, can be extended to other large buildings which have variable but predictable occupancy patterns.

This study examines the environmental and economic effects of green information technology (IT). Green IT describes two sets of IT innovations: one set includes innovations that are implemented to reduce the environmental impact of IT services in organizations; and the other IT to reduce the environmental impact of other organizational processes. The two sets respond to the call for more environmentally friendly or “greener” organizational processes. I developed and tested a preliminary model. The model applied the resource based view (RBV) of the firm (Wernerfelt 1984) the stakeholder theory (Freeman 1984) and included four constructs: (1) BAS implementation; environmental value conceived in a novel way as the conservation of electric energy in buildings; economic value -- from energy cost savings; and BAS complements. These four constructs formed three propositions: (1) BAS implementation is positively associated with environmental value; (2) environmental value is positively associated with economic value; and BAS complements moderate the relationship BAS implementation and environmental value. The model was used to guide the investigation of three research questions: 1. What are the environmental and economic values of green IT? 2. How do green IT create the above values? 3. Are other dimensions of value created? If so, what are they? The focal IT investigated was the building automation system – a system designed to conserve electric energy and decrease operational costs. The unit of analysis of the study was the facilities management team – the implementers of the system. I collected data on a sample of six diverse cases of BAS implementations. The cases were diverse in terms of the BAS types, the building purposes, the building locations and the building occupancy and management. Two types of BAS were involved in the study, each with a different level of artificial intelligence: the more intelligent BAS self-reconfigured when changes in setpoints, for example, were necessary; the less intelligent BAS must be reconfigured by an engineer in similar circumstances. There was also diversity in terms of the buildings in which the systems were implemented and the occupancy and management of the buildings. The buildings include: the corporate headquarters of a global telecommunications firm; university classrooms; a residence hall in a university; and three multi-tenanted office complexes. The building occupancy and management differ in that some buildings are owner-occupied and are managed in-house, while the others are leased and their management outsourced. Data collection involved recorded semi-structured interviews of three sets of users in the organizations: building engineers; chief engineers; and property/facilities managers. The interviews were prearranged and were conducted onsite using an interview protocol. Each interview lasted approximately one hour and was conducted in one session. The data were transcribed and analyzed in Nvivo 10. The findings showed support for the presence of the four constructs within the preliminary model as well as for the three propositions in the preliminary model. The data also revealed contextual details of the BAS implementation and BAS complements constructs. There were also new dimensions value including: unanticipated types of economic value (including savings from reduced labor demand; social value (comfort and safety for building occupants); and strategic value (knowledge used to position the organizations for greater efficiency and effectiveness). Overall, the value outcomes of the implementations can be summarized as short term social, environmental and economic value as well as strategic value – consistent with the concept of sustainable value defined by Hart et al. (1995). Also, consistent with Zuboff’s (1985) description of the duality of intelligent IT systems -- the ability to informate and automate, the BAS implementation construct was found to include two distinct sources of value: equipment automation; and equipment information. The unanticipated value dimensions and types, as well as the sources of value were used to refine the research model. The study therefore a preliminary theoretical model – the resource based view of the sustainable organization (RBV-SO) -- as well as contextual implementation details that can be used to guide future investigations of the value created by intelligent green IT systems such as the BAS, as well as measurement items that can be used to inform quantitative studies of these systems. The study also adds to the practical body of knowledge concerning green IT implementations in general and implementations of the BAS in particular, concerning: details of the information value – for example, for measuring the environmental impact of the system and for substantiating claims in the application for green funds available to organizations; and details of some key complementary resources that enhance value creation within the context. Two major limitations of this study are: (1) a single coder was used in the analysis process and therefore no inter-coder reliability was established for the results; and (2) user perceptions rather than actual quantities were used to validate the findings. Some future research prospects include: use of these findings to conduct a quantitative study of an intelligent system extended with, for example, investigation of the impact of external forces such as government regulations, environmental issue salience, and market forces on the value created by green IT (such as the BAS); and investigation of the impact over time of the development of the strategic capabilities enabled by the BAS on creation of value.