Inherent correlation between the total output cooling capacity and equipment sensible heat ratio of a direct expansion air conditioning system under variable-speed operation (XXG SMD SHR DX AC unit)

Xiangguo Xu, Liang Xia, Ming Yin Jonathan Chan, Shiming Deng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

36 Citations (Scopus)


Appropriately controlling indoor air humidity at a suitable level in buildings is important. To simultaneously control both indoor air dry-bulb temperature and relative humidity requires the match between the total output cooling capacity of an A/C system and the total cooling load in a space served by the A/C system, as well as the Equipment sensible heat ratio (SHR) of the A/C system and the Application SHR of the conditioned space. This paper reports on an experimental study on the inherent correlations between the total output cooling capacity and Equipment SHR of a DX A/C system. Experiments were carried out under different combinations of compressor speed and supply fan speed, and also under different inlet air conditions to the DX evaporator. The results obtained would lead to a better understanding of the operating characteristics of a DX A/C system under variable-speed operation, as well as the constraint of using these characteristics in developing appropriate control strategies, so as to better design, operate and control DX A/C systems for improved indoor thermal environmental control.
Original languageEnglish
Pages (from-to)1601-1607
Number of pages7
JournalApplied Thermal Engineering
Issue number13
Publication statusPublished - 1 Sep 2010


  • Air conditioning
  • Control
  • Direct expansion
  • Humidity
  • Sensible heat
  • Variable speed

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Industrial and Manufacturing Engineering

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