Arts Design & Architecture

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  • (1998) Motalebi-Esfidvajani, Ghasem

  • (1994) Kim, Yong-Su
    To deal with risks and uncertainties in life cycle costing explicitly and objectively, this thesis proposes a probabilistic model using simulation and applies the model to apartment buildings constructed by the KNHC in Korea. The proposed model was developed in a deductive way based on apartment management practice. The model incorporates capital costs, operation and minor maintenance costs, utility costs, major maintenance costs, and removal costs. Required data were collected by a survey using structured interview schedules. Each cost group was analysed, statistically modelled, and combined in the suggested simulation model. The model extends current models by introducing the concepts of replacement cycles and maintenance ratios in the form of probability distributions to predict major maintenance costs. It uses a regression model and its prediction intervals to estimate operation and minor maintenance costs. It is also possible to explore dynamically the risk implications by varying key parameters. The study also pioneered a data screening technique based on current building conditions to account for different levels of past and current maintenance. Through the application, it is demonstrated that the model can significantly improve the realism of life cycle costing, and that the model is highly suitable for analysing risks in life cycle costing. It can be used not only for risk analysis involved in life cycle costing of buildings but also for selecting design alternatives, decision making related to project feasibility, required sinking funds estimation, and maintenance planning. The expected life cycle cost for the KNHC's apartments is I, 787,827 Won/m2 with a standard deviation of 73 ,268 Wonlm2 in 1992 constant terms over 50 years. The proportion of each cost group to the life cycle cost is: major maintenance costs (31.8%), utility costs (27.4%), capital costs (25.4%), operation and minor maintenance costs (13 .5%), and removal costs (1.9%). Avoidable costs resulting from early replacements add up to 116,149 Wonlm2 (25.6% of the capital costs) in 1992 discounted terms. This cost can be significantly reduced by the extended use of structurally sound existing buildings, if more resources are allocated to maintenance.

  • (1993) Prasad, Deo K.
    Tirls thesis undertakes a detail study of the solar-optical properties of window systems. Most of the theoretical procedures for characterisation and energy performance evaluation available to day, were developed between three and five decades ago. At that time, they were designed to solve some basic problems and as a result, a large number of assumptions were made about the various heat transfer mechanisms and the material characteristics. In recent times, there have been significant developments in glazing materials, prompted mostly by concern for energy efficiency in buildings. The simple window characterisation procedures do not apply as well to these advanced glazing systems, neither does the single number characteristic when applied in dynamic energy simulation models. This study therefore has discussed the key heat transfer mechanisms in relation to window heat transfer. The two key parameters influencing window energy perfonnance have been their thermal (U-value) and solar performance (SHGC). The wide ranging procedures for characterising solar performance has also been discussed. It became evident from the discussions that despite its sensitivity to alternative test methods and the assumptions about standardised ambient test conditions, the U-value test procedures are relatively well developed and accepted. This however, cannot be deduced for solar properties. Strong arguments have been put forward for replacing the shading coefficient with solar heat gain coefficient in dynamic energy models. It is the area of characterising solar performance which was found to be most in need of attention. The key contribution of this work therefore, has been the development of a unique fullscale outdoor solar calorimeter for testing solar performance of glazing systems. A number of simple systems were tested and the results compared with existing and conventional methods of testing and calculation (to derive the same property: solar heat gain coefficient SHGC). After construction, there was a long period of calibration and fme-tuning required before meaningful results were obtained. The comparisons were very favorable. This thesis describes the facility and the potential sources of error in using such an outdoor testing procedure. It also presents a procedure for representing the SHGC values over time. Furthermore, it makes suggestions for ongoing research to improve characterisation procedures and validate dynamic energy simulation models. Its use for testing non-planar materials is strongly recommended.