M.N. Assimakopoulos

Indoor air quality in a metropolitan area metro using fuzzy logic assessment system.

According to past experience, the concentration of air pollutants indoor varies significantly in different environmental conditions. The present study focuses on the investigation of the indoor air quality (IAQ) of the underground trains in Athens, Greece. The investigation was performed in both major lines of the ATTIKO METRO. Monitoring was performed in order to determine the concentration of pollutants and particulate matter, specifically TVOCs, PM10, ΡΜ2.5, ΡΜ1 as well as temperature and relative humidity in the coaches of the trains. In the present study, a methodology based on fuzzy inference systems to assess air quality is proposed. A fuzzy logic assessment system (FLAS) is developed incorporating rules stem collected from real data, human experience and intuition. The results demonstrate the applicability and effectiveness of the FLAS.

A holistic approach for the assessment of the indoor environmental quality, student productivity, and energy consumption in primary schools

The perception of the indoor environmental quality (IEQ) through questionnaires in conjunction with in-field measurements related to the indoor air quality (IAQ), the thermal comfort and the lighting environment were studied in nine naturally ventilated schools of Athens, Greece. Cluster analysis was carried out in order to determine the ranges of indoor air pollutants, temperature (T), relative humidity (RH), and ventilation rates at which the students were satisfied with the indoor environment. It was found that increased levels of particulate matter did not have a negative effect on students’ perception while students seemed to link the degradation of IAQ with temperature variations. Statistically significant correlations were further found between measurement results and students’ perception of the IEQ. Students’ sick building syndrome (SBS) symptoms and performance of schoolwork were also investigated as a function of the levels of indoor air pollutants and ventilation, and there were found significant positive correlations between particulate matter (PM) and certain health symptoms. Students’ learning performance seemed to be affected by the ventilation rates and carbon dioxide (CO2) concentrations while certain health effects positively correlated to the levels of PM and CO2. The energy consumption of schools was rather low compared to other national findings, and both the electricity and oil consumption for heating positively correlated to the levels of indoor air pollutants.

Correlation of Particulate Matter with Airborne Fungi in Schools in Greece

Abstract The concentration levels of particulate matter (PM), airborne fungi, carbon dioxide as well as temperature and relative humidity were investigated in the indoor and outdoor environment of two schools in Athens, Greece during the period January to May 2011. The overall concentration ranges of the indoor measured pollutants were: PM10: 14.92–166.18 μg/m3, PM2.5: 3.16–31.27 μg/m3, PM1: 0.72–9.01 μg/m3, UFP: 4188–63093 pt/cm3, total airborne fungi: 28-2098 CFU/m3 and CO2: 389–1717 ppm. The relationships between PM and airborne fungi were mainly examined, and bivariate correlations of all the measured environmental parameters are also reported. The results indicate that PM of certain aerodynamic diameters significantly correlate to the total airborne fungi and their prevalent genera, Penicillium, Cladosporium and Aspergillus. Principal Component Analysis (PCA) was conducted so as to cluster variables of common characteristics. Furthermore, simple and multiple linear regression models were developed to investigate several cases of dependent variables to be used for prediction purposes in health risk assessments.

Moisture Sorption Properties of Modified Porous Clays for Roof Evaporative Cooling Applications

Abstract This research concentrates on evaporative cooling, a sustainable and alternative way to cool a roof surface by taking advantage of the properties of porous materials. During periods of rain or high humidity nights, water sorbents store moisture in their small pores inside their particles. During a warm sunny day, the latent heat released due to evaporation of moisture, maintains the surface temperature at low level. Lower roof temperatures contribute to smaller heat flow inside the building while reducing the cooling load. In this work, materials consisting of ordinary soil, montmorillonite and modified clays were used. Prior to moisture sorption experiments, materials were characterized by techniques including X–ray diffraction, X–ray fluorescence, thermogravimetric analysis and porosimetry. In order to determine the sorption isotherms, dry specimens were placed initially in desiccators above four different saturated salts in water solutions (32.8% to 93.6%). The modified clay was found to have the highest equilibrium state (10% after almost 4 days of sorption at high relative humidity). Also the moisture sorption rate of the modified clay was faster than the rest of the materials and equilibrium was attained in less than 12 hours. Moreover, a specific environment chamber was developed and tested for the evaporative cooling properties of the materials. The lower observed surface temperatures under simulating radiation of the modified clays in comparison to ordinary soil, indicated their significant potential for evaporative cooling applications.

Particulate Matter and Airborne Fungi Concentrations in Schools in Athens

Indoor Air Quality degradation is of exceptional concern due to the potential adverse effects indoor air pollutants have on human’s health. Students are a susceptible group of people, who spend a lot of their time within classrooms. The purpose of this study is to investigate the concentration levels of particulate matter (PM) and total airborne fungi, in school classrooms. Further objective is to examine possible correlations between PM10, PM2.5, PM1, ultrafine particles (UFPs, diameter <100 nm), and airborne fungi. The measurements were performed using fully automated instrumentation. The results indicate that a lot of PM10 concentrations exceeded the proposed daily limit of 50 μg/m3. Also, in some cases the concentration of the total airborne fungi indoors, exceeded their concentration outdoors. There is evidence that certain correlations exist between PM and airborne fungi.

Bioclimatic Design Simulation: An Object Oriented Approach for Energy Load and Natural Ventilation Calculations

Abstract During the past few years, the research team of the University of Michigan has developed techniques to solve problems associated with designing a performance evaluation tool environment. This paper describes the development of a system (Web-IBEDO) that makes use of emerging communication technology. The system is being used as a model for a larger implementation of distributed multi-simulation environment that provides quantitative data for bioclimatic building design. Web-IBEDO is a computer program that supports the simultaneous integrated use of simulation tools and multiple databases, over the World Wide Web (www). This energy performance simulation system has been developed using the Microsoft Visual Basic ActiveX DLL technology that supports Object Linking and Embedding (OLE). The systems engine resides on a web server and is controlled by a web-browser. The goal is to deliver this tool to all the design actors via the network and thus enhance the capabilities of sharing specialized knowledge among the project participants.