Epidemiological studies have shown that exposure to dust particle whether in the long term or short term leads to complications and even death when their concentration is less than national controlling standards. The concentration of aerosol particles in the interior is two to five times, and sometimes even hundred times, more than the concentration of pollutants in the open air. Specifically, the percentages of deposited 25 μm particles under the vertical, 60° inclined, 30° inclined and horizontal discharge modes were about 36, 45, 66, and 49%, respectively.Īerosol particles are common air pollutants in the indoor environment. As the particle size increased, the percentage of filtered particles decreased, while the percentage of particles deposited on the floor increased. The results also indicated that after about 975, 1800, 1390 and 940 s, the concentration of 2.5 μm particles reached 1% of their initial concentration, for vertical, 60° inclined, 30° inclined and horizontal fan-coil discharge modes respectively. Also, for all discharge modes, the percentage of 2.5 μm deposited particles on the floor was less than 1%. The results indicated that the percentages of 2.5 μm filtered particles for vertical, 60° inclined, 30° inclined, and horizontal fan-coil discharge modes after 600 s were about 93, 84, 76 and 93%, respectively. The particles with 2.5, 10, and 25 μm diameters were considered to examine the effect of particles size on their distribution and deposition. Accordingly, the concentration of particles with a uniform initial distribution was evaluated in the room while considering the occupants’ thermal comfort conditions for four different modes of airflow using computational fluid dynamics and solver packages developed in OpenFOAM® solver by the authors. Thus, the present study aims to investigate the indoor air quality in a room with vertical, 60° inclined, 30° inclined, and horizontal discharge fan-coils. Floor-mounted fan-coils have various airflow directions, but the effects of different directions on particle distribution and deposition have not been investigated in previous studies. Given the high concentration of particulate pollutants in the indoor environment compared to outdoor environment and their harmful effects on human health, it is important to examine the effect of indoor ventilation systems on distribution and deposition of particulate pollutants.

Fan airflow direction