Applying a novel extra-low temperature dedicated outdoor air system in office buildings for energy efficiency and thermal comfort

Han Li, Wai Ling Lee, Jie Jia

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)


A novel dedicated outdoor air system consisting of a multi-stage direct expansion coil and a zero-energy heat pipe to generate extra-low temperature outdoor air to avoid moisture-related problems was proposed in this study. The proposed system's performance in achieving the desirable air conditions and better energy efficiency objectives is compared with a conventional direct expansion system for air-conditioning of a typical office building in Hong Kong based on simulation investigations. The simulations were carried out using equipment performance data of a pilot study, and realistic building and system characteristics. It was found that the proposed system, as compared to the conventional system, could reduce the annual indoor discomfort hours by 69.4%. An energy and exergy analysis was also conducted. It was revealed that the proposed system could reduce the annual air-conditioning energy use by 15.6% and the system exergy loss rate by 13.6%. The associated overall exergy efficiency was also found 18.6% higher. The findings of this study confirm that the proposed system is better than the conventional system in terms of both energy and exergy efficiency and the desirable air conditions.
Original languageEnglish
Pages (from-to)162-173
Number of pages12
JournalEnergy Conversion and Management
Publication statusPublished - 1 Aug 2016


  • Building energy simulation
  • Dedicated outdoor air system
  • Energy and exergy
  • Heat pipe
  • Office building
  • Thermal comfort

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

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