Building parameters linked with indoor transmission of SARS-CoV-2

Seasonal thermal performance of double and triple glazed windows with effects of window opening area

Despite significant advancements in building technologies, a critical gap exists in understanding how Solar Heat Gain and the Cooling Effect of Ventilation (CEV) interact in high-rise residential buildings. These two factors, which are crucial for achieving thermal comfort, operate in opposing directions: Solar Heat Gain leads to heat retention and an increase in indoor temperature, while CEV promotes cooling and reduces indoor temperature. This contradiction creates a complex thermal dynamic that is not well-understood, particularly in the context of high-rise bedrooms with varying window configurations. This study addresses this gap by investigating the seasonal interplay between Window Opening Area (WOA), Solar Heat Gain, and CEV, explicitly focusing on their seasonal variability and the impact of different glazing configurations (double- and triple-glazed windows). This research is conducted in Dongguan, China, and employs field measurements from seven high-rise bedrooms in winter and summer. The study uses advanced instruments such as pyranometers and anemometers to capture precise data on solar radiation, indoor temperature, and airflow, enabling a detailed analysis of the thermal effects of WOA and glazing configurations. The results reveal distinct seasonal behaviours of Solar Heat Gain and CEV. Solar Heat Gain dominates in winter, with heat retention critical for indoor comfort. Smaller WOAs enhance net heat gain, especially in triple-glazed configurations, where Solar Heat Gain values for a 0.32 m2 WOA reached 281-387 W, yielding a positive Net Thermal Effect of up to + 204 W. Conversely, larger WOAs during winter facilitated minimal cooling through ventilation, reducing Net thermal effect and compromising warmth. In summer, the emphasis shifts to ventilation cooling, with CEV becoming the primary driver of thermal comfort. For a fully open WOA (1.3 m2), double-glazed rooms demonstrated significant cooling, with CEV values reaching 1327 W, resulting in negative Net thermal effect values of - 41 to - 60 W. Triple glazing, while reducing Solar Heat Gain to 1001 W offered less effective natural cooling, with CEV peaking at 1179 W. Regression analysis underscores the strong positive correlation between WOA, Solar Heat Gain, and CEV, with double-glazed systems exhibiting higher sensitivity to WOA changes. The Net thermal effect analysis highlights the necessity of adjusting WOAs seasonally-smaller openings in winter maximise heat retention, while larger openings in summer optimise ventilation cooling. This study bridges critical knowledge gaps in thermal comfort optimisation for high-rise residential buildings, emphasising the dynamic balance required between glazing types and seasonal WOA adjustments. The findings provide actionable insights for architects and engineers, supporting adaptive design strategies that balance solar heat gain and ventilation cooling, aligning with sustainability goals and energy-efficient urban living.

CO2 Levels in Classrooms: What Actions to Take to Improve the Quality of Environments and Spaces

Indoor air quality (IAQ) is a crucial priority, especially since people spend most of their time indoors. Indoor air can be more polluted than outdoor air due to sources such as building materials, cleaning products, and heating systems. This condition can affect health and productivity, especially in schools and work environments. Students spend about a third of their day in classrooms, and studies have shown that poor IAQ can cause respiratory and allergic problems, especially among children, who are more vulnerable. Poor ventilation and excessive CO2 concentration are indicators of suboptimal indoor air quality, which can lead to symptoms such as headaches, fatigue, and worsening asthma. In Italy, the lack of specific legislation on indoor air quality in schools is a problem, but improved ventilation, both natural and mechanical, and monitoring of CO2 levels are recommended to prevent negative health consequences. This paper aims to describe a methodology to improve IAQ in schools. The paper discusses the results of a study conducted on CO2 and PM10 levels measured in real time in cold season (Nov–Mar) in different classrooms of primary and secondary schools present in a large Italian urban area in order to understand the IAQ state and identify possible improvement actions.

A critical review of research methodologies for COVID-19 transmission in indoor built environment

The Coronavirus Disease 2019 (COVID-19) has caused massive losses for the global economy. Scholars have used different methods to study the transmission mode and influencing factors of the virus to find effective methods to provide people with a healthy built environment. However, these studies arrived at different or even contradictory conclusions. This review presents the main research methodologies utilized in this field, summarizes the main investigation methods, and critically discusses their related conclusions. Data statistical analysis, sample collection, simulation models, and replication transmission scenarios are the main research methods. The summarized conclusion for prevention from all reviewed papers are: adequate ventilation and proper location of return air vents, proper use of personal protective equipment, as well as the reasonable and strict enforcement of policies are the main methods for reducing the transmission. Recommendations including standardized databases, causation clarification, rigorous experiment design, improved simulation accuracy and verification are provided.

Linkage between Airborne Particulate Matter and Viral Pandemic COVID-19 in Bucharest

The long-distance spreading and transport of airborne particulate matter (PM) of biogenic or chemical compounds, which are thought to be possible carriers of SARS-CoV-2 virions, can have a negative impact on the incidence and severity of COVID-19 viral disease. Considering the total Aerosol Optical Depth at 550 nm (AOD) as an atmospheric aerosol loading variable, inhalable fine PM with a diameter ≤2.5 µm (PM2.5) or coarse PM with a diameter ≤10 µm (PM10) during 26 February 2020-31 March 2022, and COVID-19's five waves in Romania, the current study investigates the impact of outdoor PM on the COVID-19 pandemic in Bucharest city. Through descriptive statistics analysis applied to average daily time series in situ and satellite data of PM2.5, PM10, and climate parameters, this study found decreased trends of PM2.5 and PM10 concentrations of 24.58% and 18.9%, respectively compared to the pre-pandemic period (2015-2019). Exposure to high levels of PM2.5 and PM10 particles was positively correlated with COVID-19 incidence and mortality. The derived average PM2.5/PM10 ratios during the entire pandemic period are relatively low (<0.44), indicating a dominance of coarse traffic-related particles' fraction. Significant reductions of the averaged AOD levels over Bucharest were recorded during the first and third waves of COVID-19 pandemic and their associated lockdowns (~28.2% and ~16.4%, respectively) compared to pre-pandemic period (2015-2019) average AOD levels. The findings of this research are important for decision-makers implementing COVID-19 safety controls and health measures during viral infections.