Journal of Health and Safety at Work

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Introduction: Introduction: Thermal comforts are one of the most human concerns in working as was as living environments in the past half century. Thermal comfort is the condition in which people are satisfied with the thermal environment, mentally. One of the new heating system employed in individual units is radiant heating system .The purpose of this study was to investigate the performance of radiant ceiling heating system and its impact on thermal comfort of workers.

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Material and Method: In the present analytical-descriptive study, the designed radiant heating systems were investigated in two repair and maintenance units, in Hamadan gas pipeline operation center. Firstly, the environment parameters, witch impact thermal comfort, were measured before and after using radiant heating system, in both understudy units. Then, wind chill index, thermal comfort indices, PMV and PPD were calculated. In addition, PPD and PMV were determined, based on workers subjective feeling by a questionnaire distributed among 22 workers.

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Results: According to the results, the radiant heating system in unit 1, has reduced the wind chill index by 42.3 Kcal/ m2.h, witch is not considered to be significant. In unit 2, wind chill index has been decreased by 109.3 Kcal/ m2.h, witch mean that thermal comfort has been changed from cold to an optimum environment. PMV n unit 1 went up by 37% after turning the system on, witch is equal to 17.24% increase in workers satisfaction. However, in unit 2, the workers satisfaction was 14.3% higher in comparison with unit 1.

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Conclusion: Due to large space of these industrial units, producing appropriate heating by convection mechanism is too difficult and expensive. The results confirmed that if radiant heating system applied based on scientific design principles they could be effective in promotion of thermal comfort due to heating surrounding surface by radiant and also reducing fuel consumption.

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Introduction: Students play a key role in shaping the future of any society and spend a significant amount of time in educational environments. Creating an optimal learning environment requires close attention to factors affecting student well-being, particularly thermal comfort and indoor air quality. This study aims to systematically review the existing literature on thermal comfort and ventilation systems in schools.
Material and Methods: This systematic review was conducted based on the Cochrane methodology, involving a comprehensive search of three major databases — Scopus, Web of Science, and PubMed — for articles published between 2020 and 2024. The inclusion criteria encompassed peer-reviewed, conference, and review articles published in English that included the keywords “thermal comfort,” “ventilation,” and “school” in their title, abstract, or keywords. Studies focusing on preschools, universities, or other non-primary/secondary educational settings, as well as those conducted during the COVID-19 pandemic, were excluded.
Results: A total of 42 articles were selected after a rigorous screening process. The highest number of publications was reported in 2023. Key findings included: Most studies focused on elementary and secondary schools. The majority of research was conducted during the summer season, which may limit generalizability across seasons. There was considerable variation in CO₂ levels, with some exceeding recommended standards. In simulation studies, DesignBuilder and EnergyPlus were the most frequently used software tools. Additionally, results showed that: Indoor air quality and thermal comfort are significantly influenced by the type of ventilation system. Schools using natural ventilation often experienced higher CO₂ concentrations and lower thermal comfort than recommended. Implementation of Demand-Controlled Ventilation (DCV) has shown promise in improving indoor air quality and reducing pollutant levels.
Conclusion: This paper can contribute to the improvement of educational space design, enhancement of student learning, and promotion of indoor environmental health. It also provides insights into the latest methods for measuring and simulating thermal comfort and indoor air quality. For more practical outcomes, long-term studies with larger sample sizes across different seasons and times of day are needed. Combining computer simulations with real-world measurements can support cost-effective and optimized design of educational spaces. Future research should focus on standardizing temperature, humidity, CO₂ levels, and selecting the most appropriate ventilation strategies for classrooms.