Chilled Ceiling Effects on the Indoor Air Quality in a Room Equipped with Displacement Ventilation System

Document Type : Full Lenght Research Article

Authors

1 Faculty of Mechanical Engineering, Concordia University, Montreal, Canada.

2 Faculty of Mechanical Engineering, Semnan University, Semnan

Abstract

Over time, many studies have proven the advantages of using chilled ceiling systems as an assistant device for covering the barriers of the stratified air distribution systems. However, previous investigations are still insufficient, especially in analyzing indoor air quality. With the aid of the computational fluid dynamics techniques and Airpak software, we attempted to determine the possible effects of the chilled ceiling on the performance of displacement ventilation by evaluating contaminant removal, ventilation effectiveness, the freshness of air, and air change efficiency. In addition, we tried to find a solution to maintain the stratified form of the contaminant profile, and reduce the impact of the negative buoyant flow caused by the chilled surface. In order to investigate, the study was analyzed with variable exhaust vent location. The results indicated that the indoor air quality indexes had the best operation compared to the other cases when the exhaust vent was placed near the occupants. Actually, by local exhaust vent strategy, the inversion phenomenon caused by chilled surface was minimized and the contaminant concentration was safer at the inhaled zone compared to the other cases. In addition, the chilled ceiling had entirely adverse effects on the mean age of air, contaminant concentration, air change efficiency and ventilation effectiveness. Nevertheless, the disturbance effect was lower when the exhaust vent placed in the vicinity of heat/contaminant sources.

Keywords

Main Subjects

References

 [1]  M. S. Yeo, I. H. Yang, K.-W. Kim, Historical changes and recent energy saving potential of residential heating in Korea, Energy and Buildings 35(7) (2003) 715-727.
 [2] B. W. Olesen, Radiant floor heating in theory and practice, ASHRAE Journal 44 (2002) 19-26.
 [3] K. N. Rhee, K. W. Kim, A 50 year review of basic and applied research in radiant heating and cooling systems for the built environment, Building and Environment 91 (2015) 166-190.
 [4] R. A. Memon, S. Chirarattananon, P. Vangtook, Thermal comfort assessment and application of radiant cooling: a case study, Building and Environment 43 (2008) 1185-1196.
 [5] C. Wilkins, R. Kosonen, Cool ceiling system: a European air-conditioning alternative, ASHRAE Journal (1992) 34-41.
[6] M. Koschenz, V. Dorer, Interaction of an air system with concrete core conditioning, Energy and Building 30 (1999) 139-145.
[7] J. L. Niu, L. Z. Zhang, H .G. Zuo, Energy savings potential of chilled-ceiling combined with desiccant cooling in hot and humid climates, Energy and Building 34 (2002) 487-495.
[8] S. Wang, M. Morimoto, H. Soeda, T. Yamashita, Evaluating the low exergy of chilled water in a radiant cooling system, Energy and Building 40 (2008) 1856-1865.
 [9] S. Schiavon, F. Bauman, B. Tully, J. Rimmer, Chilled ceiling and displacement ventilation system: laboratory study with high cooling load, Science and Technology for the Built Environment, 21 (2015) 944-956.
 [10] A. Novoselac, J. Srebric, A critical review on the performance and design of combined cooled ceiling and displacement ventilation systems, Energy and Building 34 (2002) 497-509.
 [11] F. Bauman, T. Webster, Outlook for underfloor air distribution, ASHRAE Journal 43 (6) (2001) 18-27.
[12] L. Zhou, F. Haghighat, Optimization of ventilation system design and operation in office environment, Part I: Methodology, Building and Environment, 44 (2009) 651-656.
 [13] R. A. Memon, S. Chirarattananon, P. Vangtook, Thermal comfort assessment and application of radiant cooling: A case study, Building and Environment, 43 (7) (2008) 1185-1196.
 [14] T. Catalina, J. Virgone, F. Kuznik, Evaluation of thermal comfort using combined CFD and experimentation study in a test room equipped with a cooling ceiling, Building and Environment, 44 (8) (2009) 1740-1750.
 [15] J. Miriel, L. Serres, A. Trombe, Radiant Ceiling Panel Heating-Cooling Systems: Experimental And Simulated Study of The Performances, Thermal Comfort And Energy Consumptions, Applied Thermal Engineering, 22 (16) (2002) 1861–1873.
[16] W. H. Chiang, C. Y. Wang, J. S. Huang, Evaluation of cooling ceiling and mechanical ventilation systems on thermal comfort using CFD study in an office for subtropical region, Building and Environment, 48 (2012) 113-127.
 [17] S. Schiavon, F. Bauman, B. Tully, J. Rimmer, Chilled ceiling and displacement ventilation system: laboratory study with high cooling load, Science and Technology for the Built Environment 21 (2015) 944-956.
 [18] D. L. Loveday, K. C. Parsons, A. H. Taki, S. G. Hodder, Displacement ventilation environments with chilled ceilings: thermal comfort design within the context of the BS EN IS07730 versus adaptive debate, Energy and Building 34 (6) (2002) 573-579.
[19] D. Loveday, K. Parsons, A. Taki, S. Hodder, L. Jeal, Designing for thermal comfort in combined chilled ceiling/displacement ventilation environments, ASHRAE Transactions 104 (1998).
[20] N. Ghaddar, K. Ghali, R. Saadeh, A. Keblawi, Design charts for combined chilled ceiling displacement ventilation system (1438-RP), ASHRAE Transactions 143 (2) (2008) 574–587.
[21] D. Xie, Y. Wang, H. Wang, S. Mo, M. Liao, Numerical analysis of temperature non-uniformity and cooling capacity for capillary ceiling radiant cooling panel, Renewable Energy 87 (2016) 1154-1161.
[22] B. Ning, Y. Chen, H. Liu, S. Zhang, Cooling capacity improvement for a radiant ceiling panel with uniform surface temperature distribution, Building and Environment 102 (2016) 64-72.
[23] M. Behne, Indoor air quality in rooms with cooled ceilings.: Mixing ventilation or rather displacement ventilation?, Energy and Buildings 30(2) (1999) 155-166.
[24] B. Rahmati, A. Heidarian, A.M. Jadidi, Investigation in performance of a hybrid under-floor air distribution with improved desk displacement ventilation system in a small office, Applied Thermal Engineering 138 (2018) 861-872.
[25] P. Raftery, K. H. Lee, T. Webster, F. Bauman, Performance analysis of an integrated UFAD and radiant hydronic slab system, Applied Energy, 90 (2012) 250-257
[26] Z. L. B. Yang , A.K. Melikov , A. Kabanshi , C. Zhang , F.S. Bauman , G. Cao , H. Awbi , H. Wig¨o , J. Niu , K.W.D. Cheong , K.W. Tham , M. Sandberg , P.V. Nielsen , R. Kosonen , R. Yao , S. Kato , S.C. Sekhar , S. Schiavon , T. Karimipanah , X. Li and Z. Lin, A review of advanced air distribution methods - theory, practice, limitations and solution , Energy and Buildings, 202 (2019).
[27] Z. Shi, Z. Lu, Q. Chen, Indoor airflow and contaminant transport in a room with coupled displacement ventilation and passive-chilled-beam systems, Building and Environment, 161 (2019).
[28] Q. Chen, W .Xu, A zero-equation turbulence model for indoor airflow simulation, Energy and Buildings, 28 (1998) 137-144.
[29] N. Kobayashi, Q. Chen, Floor-Supply Displacement Ventilation in a Small Office, Indoor and Built Environment, 12 (4) (2003) 281-291.
[30] ISO7730, Moderate Thermal Environments – Determination of the PMV and PPD Indices and Specification of the Conditions for Thermal Comfort, International Standard Organization, Geneva, (1994).
[31] ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, (2004).

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History

  • Receive Date: 15 March 2021
  • Revise Date: 23 July 2021
  • Accept Date: 09 August 2021

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