Guidance to assess ventilation performance of a classroom based on CO2 monitoring

Since the COVID-19 pandemic, the ventilation of school buildings has attracted considerable attention from the general public and researchers. However, guidance to assess the ventilation performance in classrooms, especially during a pandemic, is still lacking. Therefore, aiming to fill this gap, this study conducted a full-scale laboratory study to monitor the CO2 concentrations at 18 locations in a classroom setting under four different ventilation regimes. Additionally, a field study was carried out in two Dutch secondary schools to monitor the CO2 concentrations in the real classrooms with different ventilation regimes. Both the laboratory and field study findings showed that CO2 concentrations varied a lot between different locations in the same room, especially under natural ventilation conditions. The outcome demonstrates the need of monitoring the CO2 concentration at more than one location in a classroom. Moreover, the monitored CO2 concentration patterns for different ventilation regimes were used to determine the most representative location for CO2 monitoring in classrooms. For naturally ventilated classrooms, the location on the wall opposite to windows and the location on the front wall (nearby the teacher) were recommended. For mechanically ventilated classrooms, one measurement location seemed enough because CO2 was well-mixed under this ventilation regime.

Contrastive Analysis on the Ventilation Performance of a Combined Solar Chimney

A combined solar chimney is proposed in this paper that integrates an inclined-roof solar chimney with a traditional Trombe wall. The ventilation performance of the combined solar chimney is analyzed numerically and then compared with the Trombe wall and the inclined-roof solar chimney. The feasibility of different operation modes and the ventilation effect under different environment conditions are also discussed. The results show that when the ambient temperature ranges from 298 to 303 K in the summer, a natural ventilation mode is appropriate. Otherwise, an anti-overheating mode is recommended. When the ambient temperature is lower than 273 K in the winter, a space heating mode has a better heating effect. A preheating mode can be employed to improve the indoor air quality when the ambient temperature is higher than 278 K. The simulation results indicates that the ventilation effect of the combined solar chimney is better than that of the Trombe wall and the inclined-roof solar chimney, and the problem of overheating can be avoided. The study provides guidance for the optimal operation of a combined solar chimney.

Assessment of ability of medical and obstetric students to achieve adequate positive pressure ventilation using basic neonatal resuscitation manikins

Introduction. The ability to perform adequate positive pressure ventilation is necessary for neonatal clinical practice. However, there are few studies on the achievements of undergraduate students on this task. It is necessary to assess health science students’ adequate positive pressure ventilation because it is vital at the beginning of their clinical activity. Objective. To evaluate the cognitive and procedural ability related to adequate positive pressure ventilation performed by 6th year medicine students and 4th year obstetrics students at a public university in Lima, Peru. Methods. We surveyed 78 medical and obstetric students in their last years of studies within six months of taking a course on neonatal resuscitation that included positive pressure ventilation theory and practice. Participants voluntarily agreed to participate in this study. Previously, we validated the survey by asking three experienced neonatologists for their expert judgments on improving the survey. The survey consists of three theoretical questions as a cognitive assessment and three practice assessment criteria qualified by observing performance using neonatal manikins. Results. Medicine students had a better practical ability (p <0.001) than obstetrics students, and obstetrics students presented better theoretical knowledge (p = 0.019). However, both groups achieved limited performance within six months of taking the neonatal clinical practice course as 21.8% of all students passed both the theoretical and practical parts of this study. Conclusion. Participants from both schools require further training alternatives to achieve adequate positive pressure ventilation performance.

A Review of Numerical Simulation as a Precedence Method for Prediction and Evaluation of Building Ventilation Performance

Natural ventilation has been used widely in buildings to deliver a healthy and comfortable indoor environment for occupants. It also reduces the consumption of energy in the built environment and dilutes the concentration of carbon dioxide. Various methods and techniques have been used to evaluate and predict indoor airspeed and patterns in buildings. However, few studies have been implemented to investigate the relevant methods and tools for the evaluation of ventilation performance in indoor and outdoor spaces. The current study aims to review available methods, identifying reliable ones to apply in future research. This study investigates scientific databases and compares the advantages and drawbacks of methods including analytical models, empirical models, zonal models, and CFD models. The findings indicated the computational fluid dynamics (CFD) model is the most relevant method because of cost-effectiveness, informative technique, and proficiency to predict air velocity patterns and ratios in buildings. Finally, widely used CFD codes and tools are compared considering previous studies. It is concluded the application of codes for research is subject to the complexity and characteristics of a studied model, the area and field of study, the desired turbulence model, and the user interface.

Abstract 12583: Low-Dose, High-Frequency Psychomotor CPR Skills Training Results in Improved and Sustained Performance of Optimal Adult/Child Ventilations in Fire-Based EMS Personnel

Background: Hyper/over-ventilation (HOV) negatively effects cerebral blood and coronary artery flow during cardiac arrest. The resuscitation quality improvement (RQI) model of low-dose, high-frequency (LDHF) CPR training has been shown to improve CPR skills. Due to the deleterious impact of HOV on survival, our study seeks to determine if the RQI model improves ventilation skills for EMS personnel. We test the hypothesis that the RQI training results in improved and sustained ventilation performance. Methods: In 2014, our department transitioned from traditional BLS/ACLS training to the RQI model. Performance metrics are captured automatically for each rescuer on a quarterly basis using high-fidelity mannequins. Inclusion: All data from adult RQI attempts by EMS personnel from 2015-2019. Exclusion: attempts by non-EMS personnel. The 1 outcome measure is the overall mean (95% CI) ventilation score (composite measure, range 0-100, derived from average volume/rate and % with correct volume). The 2nd outcome measure is the proportion (95%CI) of rescuers with ventilation scores >90%. Data were extracted from RQI and analyzed with Prism statistical software. Comparisons for the 1 outcome was performed using one-way ANOVA and we report mean and 95% CI and proportions and 95% CI as appropriate. Results: During the study period, 740 personnel completed 1,490 ventilation activities in the baseline period and 5,077 in the subsequent years. The mean (95% CI) composite ventilation scores for the baseline was 84.10 (83.09,85.10) vs 2016 = 83.13 (82.17,84.09), 2017=88.79 (87.91,89.66), 2018=90.36 (89.45, 91.27), 2019= 88.59 (87.37, 89.81) for years 2016-2019; F= 41.36, R2=0.024, p value <0.0001. 10outcome: In the baseline RQI year, there were 55.3 % (95%CI= 52.8,57.8) participants with composite ventilation scores >/=90% vs. 2016= 53.5% (51.2,55.8), 2017=65.2%(62.6,68.6), 2018= 71.7%(69.1,74.3) and 2019=69.3%(66.1,72.2) in subsequent years. Limitations: Individual performance not reported, single agency. Conclusions: LDHF CPR training improves proper, and exceptional, ventilation performance in fire-based EMS personnel. Our results may be useful for other EMS agencies who are considering transitioning to LDHF training such as the RQI system.