Investigation of Indoor Environment Quality in Classroom - Case Study

Analysis of standard unit carbon emission and cost assessment of the changing building envelope over material production phase

It is undeniable that the material production stage is crucial to the whole life cycle of structures. This study proposes the window-to-envelope ratio (WER) based on standard units to determine the inherent relationship between changes in door and window areas and carbon emissions, presuming six distinct types of engineering practices for various buildings are selected. It was concluded that larger door and window areas would result in more embodied carbon emissions. Additionally, as the size of windows and doors increases, the costs and embodied carbon of prefabricated and cast-in-place construction become more comparable. According to the analysis, when the building scale is larger and the door and window opening area is also larger, prefabrication has more potential for saving carbon than cast-in-place building, but with a cost of approximately 10-20% higher. Considering the perspective of consumers, producers, and markets, this study revealed a costing assessment methodology based on standard units for prefabricated structures. In this methodology, producers choose and create various residential layouts based on the distinctive requirements of consumers, while tracking the trends in carbon emissions and production costs. This assessment method tries to create a favorable atmosphere for moral market activity and offers an acceptable solution for the trade-off between environmental and economic factors throughout the material production phase of the building.

Assessment of indoor air quality and risk of COVID-19 infection in Spanish secondary school and university classrooms

Despite the risk of transmission of SARS-CoV-2, Spanish educational centers were reopened after six months of lockdown. Ventilation was mostly adopted as a preventive measure to reduce the transmission risk of the virus. However, it could also affect indoor air quality (IAQ). Therefore, here we evaluate the ventilation conditions, COVID-19 risk, and IAQ in secondary school and university classrooms in Toledo (central Spain) from November 2020 to June 2021. Ventilation was examined by monitoring outdoor and indoor CO2 levels. CO2, occupancy and hygrothermal parameters, allowed estimating the relative transmission risk of SARS-CoV-2 (Alpha and Omicron BA.1), H r, under different scenarios, using the web app COVID Risk airborne . Additionally, the effect of ventilation on IAQ was evaluated by measuring indoor/outdoor (I/O) concentration ratios of O3, NO2, and suspended particulate matter (PM). University classrooms, particularly the mechanically ventilated one, presented better ventilation conditions than the secondary school classrooms, as well as better thermal comfort conditions. The estimated H r for COVID-19 ranged from intermediate (with surgical masks) to high (no masks, teacher infected). IAQ was generally good in all classrooms, particularly at the university ones, with I/O below unity, implying an outdoor origin of gaseous pollutants, while the source of PM was heterogeneous. Consequently, controlled mechanical ventilation systems are essential in educational spaces, as well as wearing well-fitting FFP2-N95 masks indoors is also highly recommended to minimize the transmission risk of COVID-19 and other airborne infectious diseases.

Airborne fungi in Universiti Sains Malaysia: knowledge, density and diversity

Airborne fungi are among common contaminants in indoor and outdoor environments, leading to poor indoor air quality (IAQ), and to some extent, implicate health risks to humans worldwide. In Malaysia, fungal contamination in institutional buildings is rarely documented although these places are frequently visited by many. This study was conducted to assess the density and diversity of airborne fungi in Universiti Sains Malaysia (USM) main campus, Penang. A total of 11 sampling sites were assessed. Fungi were collected by using Andersen Single Stage Impact Air Sampler N-6 and MEA plates. Two separate trials, namely Trial 1 and Trial 2, were conducted in 2008 and 2019, respectively. The recovered fungi were identified up to the genus level-based morphological features. A survey involving 400 respondents among USM staff and students in relation to fungal contamination in indoor air environment was also conducted to evaluate the knowledge on indoor fungi among USM community. The densities of indoor air fungi in Trial 1 were higher; ranging from 81 to 1743 CFU/m³, exceeding the recommended level set by the Malaysia Industry Code of Practice (MCPIAQ) in some sampling sites, compared to that of in Trial 2 where the densities ranged from 229 to 699 CFU/m³. A total of 154 isolates and 230 isolates of airborne fungi were recovered in Trial 1 and Trial 2, respectively. In total, 11 fungal genera were identified in both trials, and three genera were predominant: Aspergillus, Penicillium, and Cladosporium. The survey also revealed that knowledge of IAQ among staff and students was limited and that they were unaware of fungal contamination and IAQ. A continuous and wide-spread awareness should be implemented at USM main campus for safer and healthier indoor air environments, particularly university students where productivity and efficiency are of the utmost importance.