Development of a building energy efficiency assessment tool for office buildings in Ghana

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November 2016
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The built environment is responsible for some of the most serious global and local environmental changes. This is exacerbated by increasing energy demands and decreasing resource availability. Building energy remains a critical criterion amongst both developed and developing nations and its availability cannot be overemphasized. In Ghana, more focus has been placed on the supply side, with measures taken to overcome the current supply deficit. In spite of the importance of improving the supply side, the demand side cannot also be overlooked. Interestingly, studies show that electricity demand is fast increasing, hence a need to relook at the strategy to curb this growing problem. In this thesis, the focus has been placed on demand side management. The thesis sought to answer one key question: how can one determine whether a building is energy efficient or not? A basic question, yet a critical starting point for energy efficiency studies in Ghana. Consequently, the overarching aim of the study was the development of a building energy assessment tool to be used in determining the energy efficiency of office buildings in Ghana. To achieve this aim, four main research objectives were formulated and a mixed methodology approach adopted. A combination of four different methods were used in this research: review of pertinent literature, Delphi survey, Delphic Hierarchy Process (DHP) and Simulation study. The first objective sought to examine methods used in building energy performance assessment towards the development of a conceptual framework. From the review of literature a conceptual framework was developed. The second objective sought to identify applicable criteria to form the dimensions of the building energy assessment method. A Delphi survey was conducted in two successive rounds following the literature review. Expert opinion from fields of academia, industry and government were assessed and consensus established showed that the international assessment methods are not fully applicable to the Ghanaian built environment. Five main bloc ks were established: the energy performance indices; calculation of energy performance; assessment of energy performance; setting of energy efficiency limit a nd energy performance labelling. Following this, the Delphic hierarchy process was used in achieving the third objective. This involved, the development of a customised weighting system for the Ghanaian environment. The resultant weighting system had build ing design having the highest weight followed by energy efficiency of building facilities. Use of renewable energy had the lowest weight. The findings reflect the current development of building energy data studies. It was noted that despite the huge role that renewable energy can play in reducing energy efficiency, current economic issues present an impediment to its investment and subsequent development. To achieve iv objective four, a simulation study was undertaken to test and validate the developed weight ing systems and further propose a grading system. Building energy data studies provided the required framework to properly develop the tool. It is important to state that the outstanding contribution of the study lies in the final tool developed for determining the energy efficiency of office buildings at the design stage. The development of a building energy assessment tool amongst many would contribute to energy security and economic stability. Such a tool can be adopted by energy planners, policy developers, building scientists, facility managers and designers in the planning, design and implementation of energy efficient building. Almost all well-known building assessment methods are updated and revised either annually or biannually. Therefore, it is recommended that the tool be subject to regular review which will inform required development and updating. Further developments should incor porate the developments of guidelines needed whilst using the tool. It is recommended that future studies explore building optimisation studies. This is necessitated by the dearth of study in this field in Ghana and a need for more direction to undergird the full utilisation of the developed tool. Also the interplay between cost and building energy efficiency is worthy of investigation in further research.
A thesis submitted to the Department of Building Technology, College of Art and Built Environment in partial fulfillment of the requirements for the degree of Doctor of Philosophy,