Numerical study of air flow and temperature distribution in a room equipped with a cooling ceiling 

The purpose of this paper is to simulate the most important problems in thermal comfort requirements, mainly a cooling ceiling system Using the RANS approach. A field flow model based on computational fluid dynamics was used to simulate the heat transfer of a room with the ceiling cooling system. The simulation is carried out using the Shear Stress Transport k-? model. The main objective is to evaluate the heat transfer of a room equipped with a cooling ceiling. Firstly, the study describes the thermal performance of the cooling ceiling. Then, the effect of the water velocity on the performance of the floor is presented. Finally, the cooling ceiling system in a room is analyzed in terms of hydrodynamic and thermal performance for different Reynolds number. In addition, the results indicate that the cooling capacity increases nearly linearly with the temperature difference between the air-room and the cooling ceiling system.

[1] S. Graziano, S., Jens, P. Marta, M.S. Assessing energy and thermal comfort of different low-energy cooling concepts for non-residential buildings, Energy Conversion and Management, Volume 76, December 2013, Pages 332-341.

[2] Yizai Xia, Mumma, A. Ceiling Radiant Cooling Panels Employing Heat-Conducting Rails: Deriving the Governing Heat Transfer Equations, ASHRAE Transactions. 2006, Vol. 112 Issue 1, p34-41. 8p.

[3] Andrés-Chicote, M. Tejero-Gonz?lez, A. Velasco-G?mez,E. F. J. Rey-Mart?nez, E. Experimental study on the cooling capacity of a radiant cooled ceiling system, Energy and Buildings, Volume 54, November 2012, Pages 207-214.

[4] K. Refet, K. New approach relevant to total heat transfer coefficient including the effect of radiation and convection at the ceiling in a cooled ceiling room. Applied Thermal Engineering, 29 (8-9), 1561-1565.

[5] Jeong, J.W. Mumma, S.A. Bahn?eth, W.P.  Energy Conservation Benefits of a Dedicated Outdoor Air System with Parallel Sensible Cooling by Ceiling Radiant Panels, ASHRAE Transactions; Atlanta Vol. 109, (2003): 627-636.

[6] Chiang, W.H.  Wang, C.Y. Huang, J.S. Evaluation of cooling ceiling and mechanical ventilation systems on thermal comfort using CFD study in an office for subtropical region, Building and Environment, Volume 48, February 2012, Pages 113-127.

[7] Xie, D. Wang, Y. Hanqing, W. Shunquan, M. Maili, L. Numerical analysis of temperature non-uniformity and cooling capacity for capillary ceiling radiant cooling panel, Renewable Energy, Volume 87, Part 3, March 2016, Pages 1154-1161.

[8] Yin, Y. L. Wang, R. Z. Zhai, X. Q.  Ishugah, T. F.  Experimental investigation on the heat transfer performance and water condensation phenomenon of radiant cooling panels, Building and Environment, Volume 71, January 2014, Pages 15-23.

[9] ASHRAE, HVAC Systems and Equipment (SI), (2008).

[10] Causone, F. Corgnati, S.P. Filippi, M. Olesen, B.W. Experimental evaluation of heat transfer coefficients between radiant ceiling and room, Energy and Buildings, 41 (2009)

[11] Su, L. Li, N. Zhang, X. Sun, Y. Qian, J.  Heat transfer and cooling characteristics of concrete ceiling radiant cooling panel, Applied Thermal Engineering, ATE, 84 (2015)

[12] Karathanassis, I.K. Papanicolaou, E. Belessiotis, V. Bergeles, G.C. Flow and Temperature Fields in Cooling Devices with Embedded Serpentine Tubes, Numerical Heat Transfer, Part A: Applications 66 (4), 349-378, 2014.

[13] Menter, F.R. Two-equation eddy-viscosity turbulence models for engineering applications, AIAA J, 32, 1598–1605 (1994).

[14] Sikula, O. Hirs, J.  Analysis of the dynamic behavior of the cooling ceiling in an office room with a view of thermal comfort, ventilation and comfort strategies, 3294- 3302, Proceedings The 23rd IIR International Congress of Refrigeration, 1-8, (2011) .

[15] Fredriksson , J.Sandberg , M. Moshfegh.B. Experimental investigation of the velocity field and airflow pattern generated by cooling ceiling beams. Building and Environment Volume 36, Issue 7, Pages 891-899 (2001).

[16] Catalina ,T. Virgone,J. Kuznik,J. Evaluation of thermal comfort using combined CFD and experimentation study in a test room equipped with a cooling ceiling, Building and Environment

Volume 44, Issue 8, Pages 1740-1750 (2009).

[17] Ansys Fluent 13.0.0, Ansys Fluent Inc., (2010)

[18] Patankar, S. V. Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New York, 1980.