Effect of inlet direction of warm air from linear openings on thermal comfort and energy consumption in an auditorium Alireza

Document Type : Review Article

Authors

1 Assistant Professor, Department of Mechanical Engineering, Dean of energy in building and thermal comfort research group, University of Birjand

2 MSc. Student, Department of Mechanical Engineering, University of Birjand

Abstract

In the present study, the effect of direction of inlet warm air from linear openings has been numerically analyzed on thermal comfort and energy consumption in an auditorium with a displacement ventilation system. For this reason, the linear openings are placed on the walls around the hall and four different inlet air angles are considered. Based on the results, for obtaining same thermal comfort conditions, the inlet air temperature must be 20.4, 20.6, 20.8 and 21.1°C, respectively for inlet angles of 0, 30, 45 and 60 degree. Also, results show that increasing the inlet angle toward the horizon can lead to decrease the mean air velocity and mean temperature in occupied zone. Moreover, horizontal air discharge to the auditorium causes more uniformity in thermal comfort conditions and more amount of energy consumption. Also, results indicate that, respectively for 30, 45 and 60° air discharge angle, the energy consumptions are 2.5%, 4.4% and 7.2% lower in relative to horizontal air discharge.

Keywords


[1]   G. Kim, L. Schaefer, Tae S. Lim, J. T. Kim, Thermal comfort prediction of an underfloor air distribution system in a large indoor environment, Energy and Buildings 64(2013)323-331.
[2]   H.B. Awbi, Ventilation of Buildings, E&FN Spon, London, 1998.
[3]  L. Magnier, R. Zmeureanu, D. Derome, Experimental assessment of the velocity and temperature distribution in an indoor displacement ventilation jet,Building and Environment 47 (2012) 150-160.
[4]   G. Cao, H. Awbi, R. Yao, Y.Fan, K. Sirén, R. Kosonen, J. Zhang, A review of the performance of different ventilation and airflow distribution systems in buildings, Building and Environment 73 (2014) 171-186.
[5] W. Sun, K.W.D. Cheong, A. K. Melikov, Subjective study of thermal acceptability of novel enhanced displacement ventilation system and implication of occupants’ personal control,Building and Environment 57 (2012) 49-57.
[6]   W. Chakroun, K. Ghali, N. Ghaddar, Air quality in rooms conditioned by chilled ceiling and mixed displacement ventilation for energy saving,Energy and Buildings 43 (2011) 2684–2695.
[7]   A. W. Woods, Sh. Fitzgerald, S. Livermore, A comparison of winter pre-heating requirements for natural displacement and natural mixing ventilation,Energy and Buildings 41 (2009) 1306–1312.
[8]   B.F. Yu, Z.B. Hu, M. Liu, H.L. Yang, Q.X. Kong, Y.H. Liu, Review of research on air-conditioning systems and indoor air quality control for human health, International Journal of Refrigeration32(2009)3–2 0
[9]   J.V.D.KOOI, A Methodology for Indoor Airflow Computations and Energy Analysis for a Displacement Ventilation System, Energy and Buildings, 14(1990)259-271.
[10]  K.W.D. Cheong, E. Djunaedy, Y.L. Chua, K.W. Tham, S.C. Sekhar, N.H. Wong, M.B. Ullah, Thermal comfort study of an air-conditioned lecture theatre in the tropics, Building and Environment 38 (2003) 63 – 73.
[11]  J. Lau, Q. Chen, Floor-supply displacement ventilation for workshops, Building and Environment 42 (2007) 1718–1730.
[12] F. Causone, F. Baldin, B. W. Olesen, S. P. Corgnati, Floor heating and cooling combined with displacement ventilation: Possibilities and limitations, Energy and Buildings 42 (2010) 2338–2352.
[13] H. Chen, S. Janbakhsh, U. Larsson, B. Moshfegh, Numerical investigation of ventilation performance of different air supply devices in an office environment, Building and Environment 90 (2015) 37-50
[14] M. H. Fathollahzadeh, G. Heidarinejad, H. Pasdarshahri, Prediction of thermal comfort, IAQ, and energy consumption in a dense occupancy environment with the under floor air distribution system, Building and Environment 90(2015) 96-104.
[15] Q. Chen, W. Xu, A zero-equation turbulence model for indoor airflow simulation, Energy and Buildings 28 (1998) 137-144.
[16] P. O. Fanger, Thermal comfort analysis and applications in environmental engineering, New York: McGraw-Hill, 1970.
[17] ANSI/ASHRAE, Standard 55-2010. Thermal Environmental Conditions for Human Occupancy, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 2010.
 [18] ISO7730, Moderate thermal environments—Determination of the PMV and PPD indices and specification of the conditions for thermal comfort, International Standards Organization, 1994.