Synergistic approaches to elevate indoor air quality: A holistic examination of classroom refinement, air exchange optimization, and flooring material impact.

This research endeavors to elevate indoor air quality within aging school environments by concentrating on refining interior finishing materials and windows. Renovations, encompassing window and floor remodeling in classrooms, aim to mitigate particulate matter (PM) infiltration and enhance air exchange rates. Utilizing SPS30 sensors for the analysis of 0.3-2.5 µm particles, with a focus on their implications for human health, the study evaluated air exchange rates, deposition rates, infiltration rates, and particle generation during classroom activities. Post-renovation results demonstrated a noteworthy decrease in air exchange rates, indicating an enhancement in airtightness. The investigation delves into particle generation with various flooring materials, accentuating the importance of opting for durable and low-particle-generating alternatives. Health risk assessments, considering multiple exposure routes (inhalation, dermal contact, and ingestion), revealed reduced risks post-renovation, particularly for children. To further optimize indoor air quality, the study suggests the implementation of air purification systems. Examination of PM generation during student activities showcased a substantial reduction post-renovation. This study underscores the positive influence of architectural enhancements on indoor air quality while acknowledging the necessity for holistic solutions and continuous research.

Evaluation of thermal/acoustic performance to confirm the possibility of coffee waste in building materials in using bio-based microencapsulated PCM.

As the demand for coffee has increased, by-product disposal has become a challenge to solve. Many studies are being conducted on how to use coffee waste as building materials to recycle it. In this study, the thermal performance and acoustic performance of a composite developed using bio-based microencapsulated phase change material (MPCM) and coffee waste were evaluated, and the composite was applied as building material. The coffee waste was successfully degreased with ethanol to produce composites, and removal of contaminants and oils was confirmed via scanning electron microscopy. In the phase change process of MPCM, an appropriate amount of thermal energy is absorbed and stored, and the temperature is maintained. MPCM was used in the mixture and the improved thermal performance was evaluated via differential scanning calorimetry analysis, revealing a latent heat of 3.8 J/g for MPCM content of 10%. Further, thermal imaging cameras revealed that an increase in the proportion of MPCM leads to a slower decrease in temperature because of the heat preserved by MPCM over time. In an acoustic performance evaluation, impedance tube test results showed different aspects depending on low, mid, and high-frequency bands. Specifically, at medium frequencies, which correspond to the range of noise generated in cafes, specimens fabricated using MPCM were confirmed to exhibit a higher sound absorption coefficient and an improved acoustic performance. Hence, the composite can be considered an eco-friendly building material with promising thermal and acoustic performance.