The transmission characteristics of indoor particles under two ventilation modes

Abstract In modern society, ventilation is an important method for removing indoor particles. This study applies the parameter of attenuation index to analyse the effect of the removal of indoor particles in the two typical ventilation modes called ceiling exhaust and slit exhaust. Experiment was conducted in a chamber and riboflavin particles were used as the indoor particles source, instantaneous microbial detection (IMD) used to measure the particulate concentration. The results showed there was obvious concentration difference in the vertical distribution for the slit exhaust when indoor particles tended stable, and the smaller the particle size was, the more obvious the difference was. Air exchange rate (ACH) is an important factor affecting the indoor particle concentration distribution. In the process of indoor free settling (air exchange rate is 0 ACH), the sedimentation rate were 0.086 h−1, 0.122 h−1 and 0.173 h−1 for the particles of 0.5–1.0 μm, 1.0–3.0 μm and 3.0–5.0 μm. When the air exchange rate increased to 2.5 ACH, the differences in the attenuation index is significant. There was also a significant linear relationship between air exchange rate and attenuation index. Furthermore, the effect of the slit exhaust mode on the removal of coarse particles is more remarkable as the increasing air exchange rate.

[1]  Judith C. Chow,et al.  Temporal and spatial variations of PM2.5 and PM10 aerosol in the Southern California air quality study , 1994 .

[2]  W. Stamm,et al.  A controlled trial of intravaginal estriol in postmenopausal women with recurrent urinary tract infections. , 1993, The New England journal of medicine.

[3]  John H. Seinfeld,et al.  Turbulent deposition and gravitational sedimentation of an aerosol in a vessel of arbitrary shape , 1981 .

[4]  P. L. Jenkins,et al.  Activity patterns of Californians: Use of and proximity to indoor pollutant sources , 1992 .

[5]  K. S. Subramanian,et al.  A multi-element profile of housedust in relation to exterior dust and soils in the city of Ottawa, Canada. , 2001, The Science of the total environment.

[6]  W. Nazaroff,et al.  SVOC partitioning between the gas phase and settled dust indoors , 2010 .

[7]  Nan Jiang,et al.  Particle image velocimetry measurement of indoor airflow field: A review of the technologies and applications , 2014 .

[8]  Elisabeth Mundt,et al.  Non-buoyant pollutant sources and particles in displacement ventilation , 2001 .

[9]  Li Nian-ping.  Effect of Air Change Rate upon Indoor Inhalable Particles Concentration in Under-Floor Distribution System , 2007 .

[10]  Yu Liu,et al.  CHARACTERIZATION OF REDISPERSION OF SETTLED PARTICULATES INTO THE SPACE WITH RAISED FLOOR AND CONVENTIONAL CEILING DIFFUSER HVAC SYSTEM , 1996 .

[11]  Bin Zhao,et al.  Comparison of indoor aerosol particle concentration and deposition in different ventilated rooms by numerical method , 2004 .

[12]  Tony Fletcher,et al.  PM10 and PM2.5 concentrations in Central and Eastern Europe: results from the Cesar study , 2001 .

[13]  Shengwei Zhu,et al.  Primary pollutants in schoolchildren's homes in Wuhan, China , 2015 .

[14]  Bin Zhao,et al.  Numerical study of the transport of droplets or particles generated by respiratory system indoors , 2004, Building and Environment.

[15]  R. Burnett,et al.  Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. , 2002, JAMA.

[16]  Bin Zhao,et al.  Indoor SVOC pollution in China: A review , 2010 .

[17]  M. Pitkäranta,et al.  Microbial communities associated with house dust. , 2013, Advances in applied microbiology.

[18]  Andrius Jurelionis,et al.  The impact of the air distribution method in ventilated rooms on the aerosol particle dispersion and removal: The experimental approach , 2015 .

[19]  Kwang-Chul Noh,et al.  Evaluation of clean air delivery rates and operating cost effectiveness for room air cleaner and ventilation system in a small lecture room , 2016 .

[20]  Qingyan Chen,et al.  Experimental measurements and numerical simulations of particle transport and distribution in ventilated rooms , 2006 .

[21]  Isabelle Momas,et al.  Nasal inflammation and personal exposure to fine particles PM2.5 in asthmatic children. , 2006, The Journal of allergy and clinical immunology.

[22]  Wei Yan,et al.  Experimental and CFD study of unsteady airborne pollutant transport within an aircraft cabin mock-up , 2009 .

[23]  D. Dockery,et al.  An association between air pollution and mortality in six U.S. cities. , 1993, The New England journal of medicine.

[24]  H. Yoshino,et al.  Effect of floor level slit exhaust ventilation system on distribution of house dust , 2012 .