Ceiling fans have been widely used as effective cooling and air mixing method for building environment conditioning. Understanding its airflow characteristics can be helpful to utilize ceiling fan or integrate it with background air conditioning system. However, the airflow induced by ceiling fan has different flow patterns under different rotating speeds and blowing directions. To date, it is still challenging to capture those complicated airflow fields in room scale. In this study, the airflow pattern induced by a ceiling fan was measured with a new technology, quad-view colour sequence particle streak velocimetry. A series of isothermal experiments were conducted under five rotation speed levels with downward and upward blowing directions in a room-size (4 m × 2.5 m × 3 m) chamber. Based on comprehensive three-dimensional three-component vector measurement results, the average velocity, turbulence intensity and vorticity on the middle section were calculated and used to analyse airflow patterns induced by ceiling fan. The results show that the blowing direction of the fan determines the indoor airflow pattern. When blowing downward, the flow will cause high diversion between jet core under the fan blades and surrounding region. While for upward blowing, the air speed in lower part of the room is much lower but pretty uniform. The detailed measured airflow fields can serve as reference for ceiling fan design and operation.
VossKVoßTOttoJ. Investigation of ceiling fans for improving summer thermal comfort. In: 2nd central European symposium on building physics. Vienna, September 9–11 2013.
2.
PresentERafteryPBragerGGrahamLT.Ceiling fans in commercial buildings: in situ airspeeds & practitioner experience. Build Environ2019;
147: 241–257.
3.
GhahramaniADuttaKYangZOzcelikGBecerik-GerberB. Energy savings from temperature setpoints and deadband: quantifying the influence of building and system properties on savings. In: Proceedings of the Winter Simulation Conference2016, Arlington, VA, USA, December 11–14 2016; pp.1000–1011.
4.
LuoMYuJOuyangQCaoBZhuY.Application of dynamic airflows in buildings and its effects on perceived thermal comfort. Indoor Built Environ2018;
27: 1162–1174.
5.
HopeP.Energy efficiency ratings: implications for the building industry in the humid tropics. Townsville, Queensland: James Cook University, 2003.
6.
ChiangHPanCWuHYangB. Measurement of flow characteristics of a ceiling fan with varying rotational speed. In: Proceedings of Clima 2007 wellbeing indoors, 9th Congress Helsinki, Finland, June 10–14 2007. REHVA World Congress, 2007.
7.
FangerPO.Thermal environment – human requirements. Environmentalist1986;
6: 275–278.
8.
ShichaoLStefanoSAlanKWilliamWN.Predicted percentage dissatisfied with ankle draft. Indoor Air2017;
27: 852–862.
9.
ZhangHArensEHuizengaCHanT.Thermal sensation and comfort models for non-uniform and transient environments, Part II: local sensation of individual body parts. Build Environ2010;
45: 380–388.
10.
SchiavonSBaumanFKoupriyanovMRafteryPKarmannC.Effect of acoustical clouds coverage and air movement on radiant chilled ceiling cooling capacity. Energy Build2017;
158: 939–949.
11.
RafteryPFizerJChenWHeYZhangHArensESchiavonSPaliagaG.Ceiling fans: predicting indoor air speeds based on full scale laboratory measurements. Build Environ2019;
155: 210–223.
12.
BricknerPWRudnickSNVincentRLHuntGMMcDevittJJStawnychyMT.Influence of ceiling fan’s speed and direction on efficacy of upperroom, ultraviolet germicidal irradiation: experimental. Build Environ2014;
92: 756–763.
13.
BottcherRWBaughmanGRDriggersLB.Temperature stratification in broiler houses and the effects of ceiling fans. Appl Eng Agric2013;
4: 66–71.
14.
ArmstrongMChihataBMacDonaldR.Cold weather destratification energy savings of a warehousing facility. ASHRAE Trans2009;
115: 513–518.
15.
GaoYZhangHArensEPresentENingBZhaiYPantelicJLuoMZhaoLRafteryPLiuS.Ceiling fan air speeds around desks and office partitions. Build Environ2017;
124: 412–440.
16.
SunYZhangY.An overview of room air motion measurement: technology and application. HVAC&R Res2007;
13: 929–950.
17.
YuHLiaoC-MLiangH-MChiangK-C.Scale model study of airflow performance in a ceiling slot-ventilated enclosure: non-isothermal condition. Build Environ2007;
42: 1142–1150.
18.
LiuSLipczynskaASchiavonSArensE.Detailed experimental investigation of air speed field induced by ceiling fans. Build Environ2018;
142: 342–360.
19.
SandbergM.Whole-field measuring methods in ventilated rooms. HVAC&R Res2007;
13: 951–970.
20.
BruunHH.Hot wire anemometry : principles and signal analysis.
Oxford:
Oxford University Press, 1995.
21.
PopiolekZJørgensenFEMelikovAKSilvaMCGKieratW.Assessment of uncertainty in measurements with low velocity thermal anemometers. Int J Vent2007;
6: 113–128.
22.
AdrianRJ.Twenty years of particle image velocimetry. Exp Fluids2005;
39: 159–169.
23.
CaoXLiuJJiangNChenQ.Particle image velocimetry measurement of indoor airflow field: a review of the technologies and applications. Energy Build2014;
69: 367–380.
24.
LiJCaoXLiuJWangCZhangY.Global air flow field distribution in a cabin mock-up measured via large-scale 2D-PIV. Build Environ2015;
93: 234–244.
25.
SunY.Volumetric particle streak-tracking velocimetry and its application in indoor airflow measurements. PhD thesis, University of Illinois, Urbana-Champaign, USA, 2007.
26.
BiwolePH.Large scale particle tracking velocimetry for 3-Dimensional indoor airflow study.
Lyon:
National Institute of Applied Sciences of Lyon, 2009.
27.
MaasHGGruenAPapantoniouD.Particle tracking velocimetry in three-dimensional flows: part 1. Photogrammetric determination of particle coordinates. Exp Fluids1993;
146: 133–146.
28.
BiwolePHYanWZhangYRouxJ-J.A complete 3D particle tracking algorithm and its applications to the indoor airflow study. Meas Sci Technol2009;
20: 115403.
29.
FuSBiwolePHMathisC.Particle tracking velocimetry for indoor airflow field: a review. Build Environ2015;
87: 34–44.
30.
FuSBiwolePHMathisC.Numerical and experimental comparison of 3D particle tracking velocimetry (PTV) and particle image velocimetry (PIV) accuracy for indoor airflow study. Build Environ2016;
100: 40–49.
31.
LiMYanYZhaoBTuJLiuJLiFWangC.Assessment of turbulence models and air supply opening models for CFD modelling of airflow and gaseous contaminant distributions in aircraft cabins. Indoor Built Environ2018;
27: 606–621.
32.
CaoSJ.Challenges of using CFD simulation for the design and online control of ventilation systems. Indoor Built Environ2019;
28: 3–6.
33.
LuoNWengWXuXFuM.Human-walking-induced wake flow – PIV experiments and CFD simulations. Indoor Built Environ2018;
27: 1069–1084.
34.
WangHZhangHHuXLuoMWangGLiXZhuY.Measurement of airflow pattern induced by ceiling fan with quad-view colour sequence particle streak velocimetry. Build Environ2019;
152: 122–134.
35.
WangHLiXShaoXWangBLinY.A colour-sequence enhanced particle streak velocimetry method for air flow measurement in a ventilated space. Build Environ2017;
112: 77–87.
36.
WangHWangGLiX.High-performance color sequence particle streak velocimetry for 3D airflow measurement. Appl Opt2018;
57: 1518–1523.
37.
Anonymous. SAI bubble generator: description and operating instructions.
New York:
SAGE, 1988.
