In this paper we explore the performance of a newly developed air conditioner which can produce different airflow modes such as dynamically changed simulated natural wind (SNW) and constant mechanical wind (CMW). Climate chamber experiments were conducted to study the demand for air movement and to compare effects of SNW and CMW on human subjects’ thermal comfort perception in warm environment. The results indicate that it was possible for subjects to remain comfortable at 28℃ and 30℃ with a suitable air velocity range of 0.4–0.6 and 0.7–0.9 m/s, respectively. Compared with CMW, SNW produced stronger cooling effect and induced better perceived thermal comfort voting from human subjects. Over 60% of these subjects preferred SNW to CMW. These experimental findings would serve as a reference for the design of more energy saving space conditioning systems in warm climates.
European Parliament and Council. Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings. Off J Eur Union2010; 153: 13–35.
4.
XiaoHWeiQJiangY. The reality and statistical distribution of energy consumption in office buildings in China. Energy Build2012; 50: 259–265.
5.
ISO 7730:2005. Moderate thermal environments – determination of the PMV and PPD indices and specification of the conditions for thermal comfort, Geneva: International Organization for Standardization, 2005.
6.
FangerPOChristensenNK. Perception of draught in ventilated spaces. Ergon1986; 12: 215–235.
7.
de DearRAkimotoTArensEBragerGCândidoCCheongKLiBNishiharaNSekharSTanabeSToftumJZhangHZhuY. Progress in thermal comfort research over the last twenty years. Indoor Air2013; 23: 1–20.
8.
ToftumJ. Air movement- good or bad?Indoor Air2004; 14: 40–45.
9.
de DearR. A global database of thermal comfort field experiments. ASHRAE Trans1998; 104: 1141–1152.
10.
ArensEXuTMiuraKZhangHFountainMBaumanF. A study of occupant cooling by personally controlled air movement. Energy Build1998; 27: 45–59.
11.
FountainMArensEde DearRFredBMiuraK. Locally controlled air movement preferred in warm isothermal environments. ASHRAE Trans1994; 100: 937–952.
12.
ScheatzleDWuHYellottJ. Expanding the summer comfort envelop with ceiling fans in hot, arid climates. ASHRAE Trans1989; 95: 269–280.
13.
TanabeSKimuraK. Importance of air movement for thermal comfort under hot and humid conditions. ASHRAE Trans1994; 100: 953–969.
14.
KuboHIsodaNEnomoto-KoshimizuH. Cooling effects of preferred air velocity in muggy conditions. Energy Build1997; 32: 211–218.
15.
GongNThamKWMelikovAKWyonDPSekharSCCheongKW. The acceptance air velocity range for local air movement in the tropics. HVAC&R Res2006; 12: 1065–1076.
16.
AtthajariyakulSLertsatittanakornC. Small fan assisted air conditioner for thermal comfort and energy saving in Thailand. Energy Convers Manage2008; 49: 2499–2504.
17.
ChowTFongKGivoniBLinZChanA. Thermal sensation of Hong Kong people with increased air speed, temperature and humidity in air-conditioned environment. Build Environ2010; 45: 2177–2183.
18.
YangBSekharSMelikovA. Ceiling-mounted personalized ventilation system integrated with a secondary air distribution system – a human response study in hot and humid climate. Indoor Air2010; 20: 1065–1076.
19.
ZhaiYZhangHZhangYPasutWArensEMengQ. Comfort under personally controlled air movement in warm and humid environments. Build Environ2013; 65: 109–117.
20.
HuangLOuyangQZhuYXJiangLF. A study about the demand for air movement in warm environment. Build Environ2013; 61: 27–33.
21.
ANSI/ASHRAE Standard 55-2013. Thermal environmental conditions for human occupancy, Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers, 2013.
22.
ArensETurnerSZhangHPaliagaG. Moving air for comfort. ASHRAE J2009; 51: 18–28.
23.
GB/T 50785-2012. Evaluation standard for indoor thermal environment in civil buildings, Beijing: Standardization Administration of China, 2012.
24.
SchiavonSHoytTPiccioliA. Web application for thermal comfort visualization and calculation according to ASHRAE Standard 55. Build Simul2013; 7: 321–334.
25.
BS EN ISO 7730: 2005. Ergonomics of the thermal environment — Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria, London: BSI, 2006.
26.
BS EN 15251:2007. Indoor environmental input parameters for design and assessment of energy performance of buildings: addressing indoor air quality, thermal environment, lighting and acoustics, London: BSI, 2007.
27.
BarbaraGChristaKUlrikeG. The significance of air velocity and turbulence intensity for responses to horizontal drafts in a constant air temperature of 23℃. Int J Ind Ergon2000; 26: 639–649.
28.
HuangLOuyangQZhuYX. Perceptible airflow fluctuation frequency and human thermal response. Build Environ2012; 54: 14–19.
29.
FangerPOstergaadJOlesenBMadsenT. The effect on man’s comfort of a uniform airflow from different directions. ASHRAE Trans1974; 80: 142–157.
30.
OuyangQDaiWLiHZhuY. Study on dynamic characteristics of natural and mechanical wind in built environment using spectral analysis. Build Environ2006; 41: 418–426.
31.
LiHChenXOuyangQZhuYX. Wavelet analysis on fluctuating characteristics of airflow in building environments. Build Environ2007; 42: 4028–4033.
32.
KangKSongDSchiavonS. Correlations in thermal comfort and natural wind. J Therm Bio2013; 38: 419–426.
33.
HuaJOuyangQWangYLiHZhuY. A dynamic air supply device used to produce simulated natural wind in an indoor environment. Build Environ2012; 47: 349–356.
34.
ZhuYXLuoMHOuyangQHuangLCaoB. Dynamic characteristics and comfort assessment of airflows in indoor environments: a review. Build Environ2015; 91: 5–14.
35.
BS EN ISO 7726:2001. Ergonomics of the thermal environment. Instruments for measuring physical quantities, London: BSI, 2001.
36.
MayerE. Physical causes for draft: some new findings. ASHRAE Trans1987; 93: 540–548.
37.
FangerPOMelikovAKHanzawaHRingJ. Air turbulence and sensation of draught. Energy Build1988; 12: 21–39.
38.
WangYLianZLanL. The effect of turbulence intensity on local skin temperature and subjective response to draft. Energy Build2011; 43: 2678–2683.
39.
Mayer E. Influence of air turbulence on the convective surface heat transfer coefficient. In: Third international conference on indoor air quality and climate. Stockholm: Swedish Council for Building Research, 1984; pp.377–382.
40.
HuangLArensEZhangHZhuYX. Application of whole-body heat balance models for evaluating thermal sensation under non-uniform air movement in warm environments. Build Environ2014; 75: 108–113.
41.
NishiYGaggeAP. Direct evaluation of convective surface heat transfer coefficient by naphthalene sublimation. Eur J Appl Physiol1970; 29: 830–838.
42.
Fanger P and Pedersen C. Discomfort due to air velocities in spaces. In: Proceedings of the meeting of B1 commission of the international institute of refrigeration, Lyngby, Denmark, June 2 1977; pp.289–296.
