Understanding of the droplet transmission of respiratory diseases is necessary to control the outbreak of COVID-19. HVAC systems considering droplet transmission are commonly used to prevent numerous respiratory diseases by reducing indoor virus concentrations. The transmission of the virus was directly related to indoor flow patterns generated by HVAC systems. Thus, a study on operating conditions such as direction or the tilt angle was required. In this study, the effective ventilation rate and probability of droplet transmission according to the tilt angle of supply air and the number of people were studied. A CO2 tracer gas method was used to validate the results of simulations. The breathing plane and personal respiratory zone were introduced for the probability of droplet transmission. The result showed that ventilation performance showed 17% of the maximum difference among tilt angles. Various turbulent kinetic energies were obtained according to the seated positions, resulting in non-uniform CO2 concentration. Numerous conditions were examined with locational analysis of individuals. As a result, the flow rates for ventilation were recommended to be higher than 250 m3/h and 350 m3/h with a tilt angle of 60° for an occupancy of 8 and 16 people, respectively.
WangDZhouMNieXQiuWYangMWangXXuTYeZFengXXiaoYChenW. Epidemiological characteristics and transmission model of Corona Virus Disease 2019 in China. J Infect2020; 80(5): 25–27.
2.
LipinskiTAhmadDSereyNJouharaH. Review of ventilation strategies to reduce the risk of disease transmission in high occupancy buildings. Int J Thermofluids2020; 7–8: 100045.
3.
Monge-BarrioABes-RastrolloMDorregaray-OyareguiSGonzález-MartínezPMartin-CalvoNLópez-HernándezDArriazu-RamosASánchez-OstizA. Encouraging natural ventilation to improve indoor environmental conditions at schools. Case studies in the north of Spain before and during COVID. Energ Buildings2022; 254: 111567.
4.
KampeEOBudaSBuchholzUHaasW. Surveillance of COVID-19 school outbreaks, Germany, March to August 2020. Eurosurveillance2020; 25(38): 2001645.
5.
Stein-ZamirCAbramsonNShoobHLibalEBitanMCardashTCayamRMiskinI. A large COVID-19 outbreak in a high school 10 days after schools’ reopening, Israel, May 2020. Eurosurveillance2020; 25(29): 2001352.
GeorgescuMRMeslemANastaseI. Accumulation and spatial distribution of CO2 in the astronaut’s crew quarters on the International Space Station. Build Environ2020; 185: 107278.
8.
ANSI/AHSRAE Standard 62.1-2019. American Society of Heating, Refrigerating, and Air-Conditiong Engineers, Inc., Atalanta (USA), 2019.
GuoM.XuPXiaoTHeRDaiMMillerSL. Review and comparison of HVAC operation guidelines in different countries during the COVID-19 pandemic. Build Environ2021; 187(4800): 107368.
11.
DingJYuCWCaoSJ. HVAC systems for environmental control to minimize the COVID-19 infection. Indoor Built Environ2021; 29(9): 1195–1201. DOI: 10.1177/1420326X20951968
12.
PrinceHatiAS. A comprehensive review of energy-efficiency of ventilation system using Artificial Intelligence. Renew Sust Energ Rev2021; 146: 111153.
13.
DiaHZhaoB. Association of the infection probability of COVID-19 with ventilation rates in confined spaces. Build Simul2020; 13: 1321–1327.
14.
MorenoTPintóRMBoschAMorenoNAlastueyAMinguillónMCAnfruns-EstradaEGuixSFuentesCBuonannoGStabileLMorawskaLQuerolX. Tracing surface and airborne SARS-CoV-2 RNA inside public buses and subway trains. Environ Int2021; 147: 106326.
15.
TzoutzasIMaltezouHCBarmparesosNTasiosPEfthymiouCAssimakopoulosMNTseroniMVorouRTzermposFAntoniadouMPanisVMadianosP. Indoor Air Quality evaluation using mechanical ventilation and portable air purifiers in an academic dentistry clinic during the COVID-19 pandemic in Greece. Int J Environ Res Pu2021; 18(16): 8886.
16.
LiCZiHWeiXXiongJ. Effect of the air supply angle of swirling diffusers on the air diffusion performance index in a vehicle assembly workshop. Indoor Built Environ2022; 31(7): 1918–1931. DOI: 10.1177/1420326X221087571
17.
LeeJEParkHCChoiHSChoSYJeongTYRohSC. A numerical study on the performance evaluation of ventilation systems for indoor radon reduction. Korean J Chem Eng2016; 33(3): 782–794.
18.
YangLLiuXQianFDuS. Ventilation effect on different position of classrooms in “line” type teaching building. J Clean Prod2019; 209: 886–902.
19.
ZhangTLiuYRaoYLiXZhaoQ. Optimal design of building environment with hybrid genetic algorithm, artificial neural network, multivariate regression analysis and fuzzy logic controller. Build Environ2020; 175: 106810.
20.
XinSXuHLiSWangWGuoJYangW. Efficiency evaluation of a floor standing air conditioner with different installation positions and air supply parameters applied to a large laboratory. J Build Eng2020; 32: 101701.
21.
HeidarinejadGFathollahzadehMHPasdarshahriH. Effects of return air vent height on energy consumption, thermal comfort conditions and indoor air quality in an under floor air distribution system. Energ Build2015; 97: 155–161.
22.
ZhangZGaoRLiuYLiuMWangYZhuWZhouLLiA. Smart air supply terminal for floor-standing room air conditioners based on the identification of human positions. Build Environ2021; 202: 108041.
23.
ChauhanRChauhanNSarnaRSharmaRKawadgaveKGaddamwarADharE. Prototyping of a Low-Cost Portable Ventilation Device for Health Care in Developing Countries. Int Res J Eng Technol2021; 8(1): 1–7.
24.
BattermanS. Review and extension of CO2-based methods to determine ventilation rates with application to school classrooms. Int J Environ Res Pu2017; 14(2): 1–22.
25.
BivolarovaMOndráčekJMelikovAŽdímalV. A comparison between tracer gas and aerosol particles distribution indoors: The impact of ventilation rate, interaction of airflows, and presence of objects. Indoor Air2017; 27(6): 1201–1212.
26.
KokkonenAHyttinenMHolopainenRSalmiKPasanenP. Performance testing of engineering controls of airborne infection isolation rooms by tracer gas techniques. Indoor Built Environ2014; 23(7): 994–1001. DOI: 10.1177/1420326X13499173
27.
ChoJ. Investigation on the contaminant distribution with improved ventilation system in hospital isolation rooms: Effect of supply and exhaust air diffuser configurations. Appl Therm Eng2019; 148: 208–218.
28.
XuCNielsenPVGongGJensenRLLiuL. Influence of air stability and metabolic rate on exhaled flow. Indoor Air2015; 25(2): 198–209.
29.
RemionGMoujalledBEl MankibiM. Dynamic measurement of the airflow rate in a two-zones dwelling, from the CO2 tracer gas-decay method using the Kalman filter. Build Environ2021; 188: 107493.
30.
RivasESantiagoJLMartínFMartilliA. Impact of natural ventilation on exposure to SARS-CoV 2 in indoor/semi-indoor terraces using CO2 concentrations as a proxy. J Build Eng2022; 46: 103725.
31.
ManualUD. ANSYS FLUENT 12.0. Theory Guide. Canonsburg, PA, 2009.
32.
HussainSOosthuizenPHKalendarA. Evaluation of various turbulence models for the prediction of the airflow and temperature distributions in atria. Energy Build2021; 48: 18–28.
33.
PeiGRimD. Quality control of computational fluid dynamics (CFD) model of ozone reaction with human surface: Effects of mesh size and turbulence model. Build Environ2021; 189: 107513.
34.
YouWShenJDingW. Improving residential building arrangement design by assessing outdoor ventilation efficiency in different regional spaces. Archit Sci Rev2018; 61(4): 202–214.
35.
MutaRChungJLiCYooSJItoK. Pollutant capture efficiencies in and around the opening surface of a fume hood under realistic conditions. Indoor Built Environ2022; 31(6): 1636–1653. DOI: 10.1177/1420326X211066538
36.
Fawwaz AlrebiOObeidatBAtef AbdallahIDarwishEFAmhamedA. Airflow dynamics in an emergency department: A CFD simulation study to analyse COVID-19 dispersion. Alex Eng J2021; 61(5): 3435–3445.
37.
ChenTFengZCaoSJ. The effect of vent inlet aspect ratio and its location on ventilation efficiency. Indoor Built Environ2020; 29(2): 180–195. DOI: 10.1177/1420326X19865930
38.
ZhuangRNLiXTuJ. A computational fluid dynamics study on the effects of computer fan on indoor airflow and indoor air quality in breathing zone. Indoor Built Environt2015; 24(3): 295–307. DOI: 10.1177/1420326X13510330
39.
HaddadSSynnefaAMarcosMÁPPaoliniRDelrueSPrasadDSantamourisM. On the potential of demand-controlled ventilation system to enhance indoor air quality and thermal condition in Australian school classrooms. Energy Build2021; 238: 110838.
40.
CaiCSunZWeschlerLBLiTXuWZhangY. Indoor air quality in schools in Beijing: Field tests, problems and recommendations. Build Environ2021; 205: 108179.
