Evaluation and investigation of the effects of ventilation layout, rate, and room temperature on pollution dispersion across a laboratory indoor environment.

The presence of chemicals in laboratories and research centers exposes the staff working at such indoor environment to health risks. In this piece of research, a study was performed on the indoor environment of the Center for Environmental Engineering Research at Sahand University of Technology (Tabriz, Iran). For this purpose, the parameters affecting the dispersion of volatile organic compounds (VOCs), including ventilation rate, room temperature, pollution emission time, venting location, air flow regime within the indoor environment, and the number of vents, were simulated via CFD modeling. The CFD modeling was performed three-dimensionally in unsteady state. In case of turbulent flow within the indoor environment, k-ε turbulence model was used to obtain air velocity profile. Experimental data was used to validate the model. Results of the present research showed that when the venting location is on the ceiling, pollution concentration of 25 ppm can be achieved at some low temperature under a particular set of conditions. However, when the venting location was on the walls close to the pollution source, concentrations as low as 5 ppm and lower were observed within the laboratory indoor environment.

Health risk assessment of VOC emissions in laboratory rooms via a modeling approach.

One of the important agents menacing buildings' employees and residents' health is the emission of volatile organic compounds (VOCs) into the indoor environment. The present research studied the VOC emission to evaluate indoor air quality (IAQ) through studying in-laboratory processes and tasks. On account of that, three different pollutants (acetone, benzene, and toluene) were chosen as candidate VOCs, and Environmental Engineering Research Center at Sahand University of Technology was selected as a sample laboratory for each VOC. Using CFD model, concentrations of pollutants under unsteady state in a three-dimensional geometry at various temperatures were provided. To validate the considered model, the modeling results were compared to experimental data. Health risk was evaluated through the building using the OEL-C, OEL-STEL, and OEL-TWA parameters for the three pollutants. According to the mentioned parameters and the modeling results, 1 h following the emission, in order to reduce the health risk associated with short-term exposure to the emission, the staff should observe a minimum distance of 3, 2, and 1.8 m to the sources of acetone, benzene, and toluene, respectively. This is while, since average concentration of emission within the laboratory in an 8-h period is several times as large as OEL-TWA, then the laboratory staffs are strictly recommended not to work in the laboratory for long hours. Furthermore, using the results of this research, the staff can detect safe locations within the laboratory without any need to use emission monitoring equipment.