Chinedum Vincent Okafor Kevin Chuks Okolie Peter Ogunoh Udeagwu Hyginus Oguike


This study carried out a comparative study to evaluate the air-conditioning performance of an office space under two typical ventilation modes (displacement and mixing ventilation system). A wall supply diffuser is located at the ceiling height for the mixing ventilation case, whereas, the supply diffuser is at the floor level for the displacement ventilation case. In both cases, the exhaust grill is located at the ceiling. From the result of the simulation, the researchers observed that the displacement ventilation system could have a higher risk of discomfort relating to vertical temperature gradient than when compared to the mixing ventilation case. More so, the simulation result indicates that the temperature distribution in an office building is a function of the type of ventilation system adopted and marginally affected by the diffuser arrangement.


Keywords: CFD, Thermal comfort, Temperature gradient, Displacement ventilation, Mixing ventilation.



. A. Noveselec and J. Srebic.2002. A critical review on the performance and design of combined cooled ceiling and displacement ventilation system. Energy and Building, [online] 34(5). pp 497-509.

. Carrier “Air conditioning company,” Handbook of air conditioning system design,4th edition, McGraw-Hill, 1965.New York, USA.

. D. Butler, Air conditioning using displacement ventilation to maximize free cooling. BRE, Watford,2012, pp. 1-20.

. T. Sodec and R. Craig.1990. Under floor air supply system-The European experience. Ashrae Transactions.96 (2). pp.690-695.

. G. Gan. 1996.Numerical Investigation of local discomfort in office with displacement ventilation. Fuel Energy.37 (2). pp. 82-157.

. Q.Chen, P.Suter, A.Moser.1991. Influence of air supply parameters on indoor diffusion. Building Environ.26 (4). pp. 417-431.

. BS EN ISO 7730. 1995.Moderate thermal environments-determining of the PMV and PPD indices and specification of the conditions for the thermal comfort. British standards Institute, London.


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