Dorizas, PV;
Indoor environmental pollution from ultrafine particles with controlled ventilation in buildings.
Doctoral thesis , UNSPECIFIED.
Abstract
The present thesis aims at investigating the factors affecting the indoor environmental quality (IEQ) in school buildings and residences. In this context, extended monitoring was performed in buildings located in areas of different microclimatic characteristics in the greater area of Attika, Greece. The research focused on the study of the indoor air quality (IAQ) while simultaneous measurements were also performed in the outdoor environment. Particulate matter (PM) of several aerodynamic diameters, carbon dioxide (CO2) concentrations and ventilation rates were extensively investigated in naturally ventilated school buildings. In addition to the experimental measurements, the diurnal variation of PM was simulated using a numerical model. The perception of the indoor environmental conditions by the users of the buildings was further examined through questionnaires and students' productivity was also studied in relation to the levels of the indoor air pollutants, the ventilation rates and the perception of the IEQ. To this end, three experimental campaigns were performed in schools and residences. The first experimental campaign was carried out in two residences in areas of different degree of urbanization. Main objective was to compare the levels of air pollutants in the two residences and also to study the parameters that affect their concentrations. The results showed significantly higher concentrations of PM, CO and CO2 in the residence at the urban area in relation to the residence at the suburban area possibly associated to the vehicle emissions from adjoining streets which in many cases also exceeded the recommended limit values. The background levels of UFP in the residence of the urban area were by three times greater than the corresponding ones of the suburban area and were significantly affected by indoor activities such as smoking, cooking and the human presence. The diurnal fluctuation of PM was also simulated using the mathematical modeling tool, MIAQ. The sensitivity of the model in the changes of infiltration rates and deposition velocities of PM10 in the absence of indoor sources was initially examined and PM10 were then simulated with the presence of indoor sources and the estimated concentrations were in good agreement with the measurement findings. In the second experimental campaign the measurements were performed in two schools of Eastern Attika where apart from the physicochemical parameters, airborne fungi, VOCs and meteorological parameters were also monitored. The measurement results showed that in many cases the concentrations of PM and airborne fungi in the classrooms were similar to the corresponding ones of the outdoor environment indicating that in the absence of intense indoor sources the outdoor environment can significantly affect the indoor one. Furthermore, 14 the correlations between all of the measured variables were examined and there were found statistically significant correlations between certain sizes of PM and airborne fungi a fact that could possibly indicate common sources between these pollutants. The third experimental campaign was conducted in school buildings mainly located in Western Attika and apart from the increase of the statistical sample, this certain campaign also involved extended monitoring of the ventilation levels and the subjective perception of the IEQ (including the IAQ, thermal comfort, lighting and acoustics) of the classrooms by the students. It was found that the ventilation rates ranged in satisfactory levels for the majority of the schools while PM10 outreached the recommend limit values by more than 6 times for all schools. The ratios of indoor to outdoor PM for all the cases were much greater than unity indicating the intense presence of indoor sources such as overcrowded classrooms, the use of chalk boards and inadequate ventilation rates for certain cases. To summarize, the levels of exposure for the majority of the cases were greater than the recommended values even though the ventilation rates were satisfactory. Apart from this, the increased levels of air pollutants were not perceived by the students whose majority evaluated the indoor air quality as satisfactory and seemed to associate high temperatures to the degradation of the IAQ. However, the thermal perception of students approached the corresponding measurements of the thermal environment. Finally, students' productivity was examined as a function of the indoor air pollutant levels, the ventilation rates and students' perception of the IEQ. Negative correlations were found between students' productivity and CO2 concentrations, and students' sick building syndrome (SBS) symptoms significantly correlated to the levels of air pollutants. Finally the energy consumption of the school buildings was examined and it was found that for the majority of the cases both the consumption for electricity and oil for heating remained in rather low levels and positively correlated to the levels of indoor air pollutants. The simulated PM10 concentrations approximated the measurements, while the emitted rate of PM10 due to the presence of students was further estimated.
| Type: | Thesis (Doctoral) |
|---|---|
| Title: | Indoor environmental pollution from ultrafine particles with controlled ventilation in buildings |
| UCL classification: | UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of the Built Environment UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of the Built Environment > Bartlett School Env, Energy and Resources |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1566354 |
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