Energy efficiency of houses and best practice urban design in the Top End

  • Shokhida Safarova

    Student thesis: Doctor of Philosophy (PhD) - CDU

    Abstract

    Energy efficiency of houses in cities in the tropical savanna climate presents challenges for urban design. Urban and suburban environments prove that prevailing breeze access has the potential to improve thermal comfort in tropical houses and reduce the energy needed for cooling. In recent years, many countries, including Australia, have introduced more stringent requirements for energy efficiency of houses. However, a review of existing design practices for housing and subdivisions in Australia’s tropical savanna climate zone identified an inadequacy of the current residential energy rating methodology as a tool for assessing tropical housing performance, that there was a lack of research on the thermal performance of modern houses operating in dual mode (natural ventilation and cooling), and on occupant thermal comfort in modern houses built under recent energy efficiency regulations.

    This research aims to investigate pathways for optimal provision of thermal comfort and sustainability of residential housing in the tropical savanna climate based on the interrelationships between climatic conditions, urban design, and occupant behaviour. The research is based on the existing design practices applied to housing and subdivisions in the tropical savanna climate with reference to two suburbs in the city of Darwin in the Northern Territory, Australia.

    The thermal performance of tropical houses was investigated based on occupant adjustment strategies and urban design factors using simulation software, climatic condition measurements, an occupant thermal comfort survey, and an analysis of energy consumption across 40 households. The simulation demonstrated that unobstructed wind flow increases thermal comfort hours predominantly in the Dry Season and reduces the cooling energy required for an elevated lightweight construction house by 17%. The analysis of postoccupancy electricity consumption of the average household confirmed wind speed and direction as significant impact factors. The survey results demonstrated that 70% of survey respondents were satisfied with indoor conditions in the Wet Season and 80% in the Build-Up in naturally ventilated houses.

    This study filled gaps left by previous studies and made a significant contribution to the knowledge of the post-occupancy performance of modern tropical houses and can contribute to the design process of future tropical urban developments.
    Date of Award2021
    Original languageEnglish
    SupervisorJeremy Trombley (Supervisor) & Stephen Garnett (Supervisor)

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