Systematic comparisons of exit air temperature and wall temperature for modelling non-uniform thermal environment of stratum ventilation

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

4 Scopus Citations
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Detail(s)

Original languageEnglish
Pages (from-to)120-133
Journal / PublicationBuilding and Environment
Volume149
Online published11 Dec 2018
Publication statusPublished - Feb 2019

Abstract

When modelling the non-uniform thermal environment of the energy efficient air distributions (e.g., stratum ventilation), the wall temperature (i.e., the inner surface temperature of an exterior wall) is conventionally required as the input to reflect the weather condition. Recently, the exit air temperature has also been used to reflect the weather condition. However, it is unknown whether the exit air temperature can provide better model performances than the wall temperature. This study systematically compares the model performances of the exit air temperature and wall temperature for the non-uniform thermal environment of stratum ventilation, using qualitative analysis, grey relational analysis and modelling analysis. Experiments in a stratum-ventilated office are conducted. Based on the experiments, the grey relational analysis confirms the results of the qualitative analysis that compared with the wall temperature, the exit air temperature has closer correlations with the indoor air temperatures and velocities. The modelling analysis using leave-one-out cross-validation further confirms that the exit air temperature can more accurately and robustly model the indoor air temperatures and velocities, with the overall mean absolute error reduced by 45.01% and 62.36% respectively, and the overall standard deviation of errors reduced by 41.76% and 74.84% respectively. The exit air temperature can be conveniently obtained from the building management system while the wall temperature cannot. Due to the ease of application and improved model performances, the exit air temperature is recommended in practice to replace the wall temperature for modelling the non-uniform thermal environment of stratum ventilation.

Research Area(s)

  • Exit air temperature, Grey relational analysis, Leave-one-out cross-validation, Non-uniform thermal environment, Stratum ventilation, Wall temperature

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