Effect of balconies on thermal comfort in wind-induced,naturally ventilated low-rise buildings

Abstract

The presence of the parapet and floor of a balcony is expected to have a range of effects on a building’s environmental behaviour, in terms of aspects, such as natural ventilation, thermal comfort, pollutant transportation and shading and daylighting. The authors have previously reported that the presence of a balcony can significantly increase the air flow rate of most rooms in a naturally ventilated building. In this study, the CFD technique and Fanger and Toftum’s extended PMV—PPD model are combined to investigate numerically the effect of a balcony on thermal comfort for naturally ventilated buildings in tropical-humid regions. The results show that although a balcony reduces the indoor average velocity for most rooms, and in turn increases the PMVnv value in both the seated and standing positions, it does not change the indoor thermal comfort level. However, the presence of a balcony improves comfort by increasing the uniformity of indoor air distribution. PMVnv is also shown to be less sensitive to velocity than PMV, allowing for a wider thermal comfort range for naturally ventilated buildings.

Practical application: This study will help designers and engineers who are considering the use of a balcony at the design stage to have a better understanding of its effect on thermal comfort in naturally ventilated buildings.

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References

Papamanolis N. An overview of the balcony’s contribution to the environmental behavior of buildings: The 21st Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 2004.

Chand I. , Bhargava PK , Krishak NLV Effect of balconies on ventilation inducing aeromotive force on low-rise buildings . Building and Environment 1998 ; 33(6): 385-96.

Prianto E. , Depecker P. Characteristic of airflow as the effect of balcony, opening design and internal division on indoor velocity: a case study of traditional dwelling in urban living quarter in tropical humid region. Energy and Buildings 2002; 34: 401-9.

Prianto E. , Depecker P. Optimization of architectural design elements in tropical humid region with thermal comfort approach. Energy and Buildings 2003; 35: 273-80.

Ai ZT , Mak CM , Niu JL , Li ZR , Zhou Q. Effect of balconies on the ventilation performance of low-rise buildings . Indoor and Built Environment 2010; under review.

Fanger PO , Toftum J. Extension of the PMV model to non-air-conditioned buildings in warm climates . Energy and Buildings 2002; 34: 533-6.

Assimakopoulos VD , Georgakis C. , Santamouris M. Experimental validation of a computational fluid dynamics code to predict the wind speed in street canyons for passive cooling purposes. Solar Energy 2006; 80: 423-34.

Elmualim AA Effect of damper and heat source on wind catcher natural ventilation performance . Energy and Buildings 2006; 38: 939-48.

Chiang CM , Lai CM , Chou PC , Li YY The influence of an architectural design alternative (transoms) on indoor air environment in conventional kitchens in Taiwan. Building and Environment 2000; 35: 579-85.

10.

Carrilho da Graca G. , Chen Q. , Glicksman LR , Norford LK Simulation of wind-driven ventilative cooling systems for an apartment building in Beijing and Shanghai. Energy and Buildings 2002; 34: 1-11.

11.

Zhang A. , Gu M. Wind tunnel tests and numerical simulations of wind pressures on buildings in staggered arrangement. Journal of Wind Engineering and Industrial Aerodynamics 2008; 96: 2067-79.

12.

Chen Q. Ventilation performance prediction for buildings: a method overview and recent applications. Building and Environment 2009 ; 44: 848-58.

13.

Chen Q. , Lee K. , Mazumdar S. , Poussou S. , Wang L. , Wang M. , Zhang Z. Ventilation performance prediction for buildings: model assessment . Building and Environment 2010; 45: 295-303.

14.

Mak CM , Cheng C. , Niu JL The application of computational fluid dynamics to the assessment of green features in buildings, Part 1: Wing walls. Architectural Science Review 2005; 48(1): 1-14.

15.

Mak CM , Niu JL , Lee CT , Chan KF A numerical simulation of wing walls using computational fluid dynamics . Energy and Buildings 2007; 39: 995-1002.

16.

Li L. , Mak CM The assessment of the performance of a wind catcher system using computational fluid dynamics. Building and Environment 2007 ; 42: 1135-41.

17.

Heiselberg P. , Svidt K. , Nielsen PV Characteristics of air flow from open windows . Building and Environment 2001; 36: 859-69.

18.

ISO730 (1994). Moderate thermal environments-determination of the PMV and PPD indices and specification of the conditions for thermal comfort. ISO , Geneva.

19.

Nevins RG , Rohles FH , Springer W. , Feyerherm AM A temperature-humidity chart for thermal comfort of seated persons . ASHRAE Transactions 1996; 72(1): 283-91.

20.

Brager GS , de Dear R. Thermal adaptation in the built environment: a literature review. Energy and Buildings 1998; 27: 83-96.

21.

de Dear R. , Brager GS Developing an adaptive model of thermal comfort and preference. ASHRAE Transactions 1998; 104(1a): 145-67.

22.

Ashrae. ASHRAE handbook of fundamentals. Thermal comfort. Atlanta, GA, USA: American Society of Heating, Refrigerating and Air conditioning Engineers, Inc., 2009.

23.

Stavrakakis GM , Koukou MK , Vrachopoulos MG , Markatos NC Natural cross-ventilation in buildings: Building-scale experiments, numerical simulation and thermal comfort evaluation. Energy and Buildings 2008; 40: 1666-81.

24.

Stavrakakis GM , Zervas PL , Sarimveis H. , Markatos NC Development of a computational tool to quantify architectural-design effects on thermal comfort in naturally ventilated rural houses. Building and Environment 2010; 45: 65-80.

25.

Jiang Y. , Alexander D. , Jenkins H. , Arthur R. , Chen Q. Natural ventilation in buildings: measurement in a wind tunnel and numerical simulation with large-eddy simulation. Journal of Wind Engineering and Industrial Aerodynamics 2003; 91: 331-53.