Investigating the Impact of (CO₂) Concentration and Healthcare Architecture on Staff Fatigue and Thermal Comfort
Karen Fatahi
1
(
Assistant Professor, Department of Architecture, Ilam Branch, Islamic Azad University, Ilam, Iran.
)
Maryam Beigi
2
(
Master's Student in Architecture, Ilam Branch, Islamic Azad University, Ilam, Iran.
)
Ali OmraniPour
3
(
Associate Professor, Faculty of Architecture, Faculty of Fine Arts, University of Kashan, Iran.
)
Keywords: Carbon Dioxide (CO₂) Air Concentration, Thermal Comfort, Heart Rate, Healthcare Architecture.,
Abstract :
Poor indoor air quality and elevated CO₂ levels in healthcare environments—due to inadequate ventilation and unfavorable environmental conditions—can compromise thermal comfort and endanger staff health. Appropriate architectural design, including optimized ventilation, daylighting, and spatial organization, can help prevent CO₂ buildup, reduce fatigue, and enhance staff performance.The aim of this study was to examine the effect of elevated CO₂ concentrations on staff fatigue and thermal comfort in healthcare facilities. An experimental study was conducted in a specialized clinic in Ilam, Iran. The study population consisted of 20 healthcare staff members working in a basement-level laboratory. Participants were randomly assigned to exposure to two different CO₂ concentrations: 1100 ppm with mechanical ventilation and 1800 ppm without mechanical ventilation.During exposure, heart rate measurements, thermal comfort assessments (using the ASHRAE standard questionnaire), and fatigue evaluations (using the standardized Multidimensional Fatigue Inventory, MFI) were recorded. Data were analyzed using Multivariate Analysis of Covariance (MANCOVA).Findings revealed that higher CO₂ concentrations (1800 ppm without ventilation compared to 1100 ppm with ventilation) had a significant impact on general, physical, and mental fatigue, as well as a decrease in staff activity and motivation (p < 0.05). Furthermore, thermal discomfort during work activities significantly contributed to general, physical, and mental fatigue (p < 0.05). Increased heart rate was also significantly associated with general fatigue and reduced activity and motivation (p < 0.05). However, the interaction effects between these factors were not statistically significant (p > 0.05).Among the various dimensions of fatigue, general fatigue emerged as the most influential factor, followed by physical and mental fatigue.According to ASHRAE standards and the results of this study, elevated CO₂ concentrations (1800 ppm vs. 1100 ppm) in healthcare environments can adversely affect fatigue levels and thermal comfort, potentially leading to serious long-term health issues for staff. The findings also demonstrated that higher CO₂ levels cause thermal discomfort, elevated heart rates, and increased general, physical, and mental fatigue, ultimately reducing staff activity and motivation.Thus, implementing effective ventilation systems and continuous monitoring of indoor air quality are essential strategies for enhancing staff performance and safeguarding the health of employees in healthcare environments.