Effect of indoor buoyancy flow on wind-driven cross ventilation
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Designing for wind-driven cross ventilation is challenging due to many factors. While studies have focused on the difficulty of predicting the total flow rate and measuring opening characteristics of cross ventilation, few have investigated the impacts on the distribution of indoor air. This paper provides insights on how local heat sources can generate significant buoyancy driven flow and affect indoor mixing during wind-driven cross ventilation scenarios. Measurements of air distribution were conducted by a tracer gas method for a multi-zone test building located in Austin, Texas, USA, along with cross ventilation flow at the openings. A computational fluid dynamic (CFD) model was also developed for this test building, which utilizes the measured flow properties at the openings as boundary conditions. Resulting air distribution patterns from the CFD model were then compared to the experimental data, validating the model. Further parametric analyses were also conducted to demonstrate the effect of interior heat loads in driving internal air mixing. Key findings of the investigation suggest a local heat source smaller than 35 W/m2 can increase the indoor mixing during cross ventilation from less than 1 air exchange to as high as 8 air exchanges per hour. This result also suggests a typical occupancy scenario (people and electronics) can generate enough heat loads to change the indoor air mixing and alter the effect of cross ventilation.
- ASHRAE (2009). ASHRAE Handbook. Fundamentals. Atlanta: American Society of Heating, Refrigerating and Air-Conditioning Engineers.
- Van Buggenhout S, Van Brecht A, Eren Özcan S, Vranken E, Van Malcot W, Berckmans D (2009). Influence of sampling positions on accuracy of tracer gas measurements in ventilated spaces. Biosystems Engineering, 104: 216–223. CrossRef
- CD-adepco (2012). Star-CCM+ User Guide Version 6.06. CD-adapco, Melville, NY.
- Chen Q (2009). Ventilation performance prediction for buildings: A method overview and recent applications. Building and Environment, 44: 848–858. CrossRef
- Chu CR, Chiu YH, Chen Y-J, Wang Y-W, Chou CP (2009). Turbulence effects on the discharge coefficient and mean flow rate of wind-driven cross-ventilation. Building and Environment, 44: 2064–2072. CrossRef
- Demmers TGM, Burgess LR, Phillips VR, Clark JA, Wathes CM (2000). Assessment of techniques for measuring the ventilation rate, using an experimental building section. Journal of Agricultural Engineering Research, 76: 71–81. CrossRef
- Etheridge DW, Sandberg M (1996). Building Ventilation: Theory and Measurement. Chichester, USA: John Wiley & Sons.
- Farhanieh B, Sattari S (2006). Development of an integrated model for airflow in building spaces. Renewable Energy, 31: 401–416. CrossRef
- Fitzgerald SD, Woods AW (2010). Transient natural ventilation of a space with localised heating. Building and Environment, 45: 2778–2789. CrossRef
- Hunt GR, Linden PF (1999). The fluid mechanics of natural ventilation—Displacement ventilation by buoyancy-driven flows assisted by wind. Building and Environment, 34: 707–720. CrossRef
- Kaye NB, Hunt GR (2007). Heat source modelling and natural ventilation efficiency. Building and Environment, 42: 1624–1631. CrossRef
- Kaye NB, Hunt GR (2010). The effect of floor heat source area on the induced airflow in a room. Building and Environment, 45: 839–847. CrossRef
- Li Y, Delsante A, Chen Z, Sandberg M, Andersen A, Bjerre M, Heiselberg P (2001). Some examples of solution multiplicity in natural ventilation. Building and Environment, 36: 851–858. CrossRef
- Linden PF (1999). The fluid mechanics of natural ventilation. Annual Review of Fluid Mechanics, 31: 201–238. CrossRef
- Linden PF, Lane-Serff GF, Smeed DA (1990). Emptying filling boxes: the fluid mechanics of natural ventilation. Journal of Fluid Mechanics, 212: 309–335. CrossRef
- Lishman B, Woods AW (2009). On transitions in natural ventilation flow driven by changes in the wind. Building and Environment, 44: 666–673. CrossRef
- Lo LJ, Novoselac A (2011). CFD simulation of cross-ventilation using fluctuating pressure boundary conditions. ASHRAE Transactions, 117(1): LV-11-C075.
- Lo LJ, Novoselac A (2012). Cross ventilation with small openings: Measurements in a multi-zone test building. Building and Environment, 57: 377–386. CrossRef
- Morton BR, Taylor G, Turner JS (1956). Turbulent gravitational convection from maintained and instantaneous sources. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 234(1196): 1–23. CrossRef
- Parker DS (2009). Very low energy homes in the United States: Perspectives on performance from measured data. Energy and Buildings, 41: 512–520. CrossRef
- Phillips JC, Woods AW (2004). On ventilation of a heated room through a single doorway. Building and Environment, 39: 241–253. CrossRef
- Seifert J, Li Y, Axley J, Rösler M (2006). Calculation of wind-driven cross ventilation in buildings with large openings. Journal of Wind Engineering and Industrial Aerodynamics, 94: 925–947. CrossRef
- Yuan J, Glicksman LR (2007). Transitions between the multiple steady states in a natural ventilation system with combined buoyancy and wind driven flows. Building and Environment, 42: 3500–3516. CrossRef
- Yuan J, Glicksman LR (2008). Multiple steady states in combined buoyancy and wind driven natural ventilation: The conditions for multiple solutions and the critical point for initial conditions. Building and Environment, 43: 62–69. CrossRef
- Effect of indoor buoyancy flow on wind-driven cross ventilation
Volume 6, Issue 1 , pp 69-79
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