Mitigating heat effects in the workplace with a ventilation jacket: Simulations of the whole-body and local human thermophysiological response with a sweating thermal manikin in a warm-dry environment

• Published in: Journal of thermal biology Vol. 119; p. 103772
• Main Authors: Del Ferraro, Simona, Falcone, Tiziana, Morabito, Marco, Bonafede, Michela, Marinaccio, Alessandro, Gao, Chuansi, Molinaro, Vincenzo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2024
• Subjects: Cooling garments; Engineering and Technology; Heat stress; Maskinteknik; Mechanical Engineering; Occupational heat strain; Production Engineering, Human Work Science and Ergonomics; Produktionsteknik, arbetsvetenskap och ergonomi; Sweating manikin; Teknik; Thermophysiological response; Ventilation jacket; Sweating manikin; Heat stress; Ventilation jacket; Occupational heat strain; Cooling garments; Thermophysiological response
• ISSN: 0306-4565; 1879-0992
• DOI: 10.1016/j.jtherbio.2023.103772

Climate change is increasingly affecting human well-being and will inevitably impact on occupational sectors in terms of costs, productivity, workers’ health and injuries.
Among the cooling garment developed to reduce heat strain, the ventilation jacket could be considered for possible use in workplaces, as it is wearable without limiting the user's mobility and autonomy.
In this study, simulations with a sweating manikin are carried out to investigate the effects of a short-sleeved ventilation jacket on human thermophysiological responses in a warm-dry scenario.
Simulations were performed in a climatic chamber (air temperature = 30.1 °C; air velocity = 0.29 m/s; relative humidity = 30.0 %), considering two constant levels of metabolic rate M (M1 = 2.4 MET; M2 = 3.2 MET), a sequence of these two (Work), and three levels of fan velocities (lf = 0; lf=2; lf=4).
The results revealed a more evident impact on the mean skin temperature (Tsk) compared to the rectal temperature (Tre), with significant decreases (compared to fan-off) at all M levels, for Tsk from the beginning and for Tre from the 61st minute. Skin temperatures of the torso zones decreased significantly (compared to fan-off) at all M levels, and a greater drop was registered for the Back.
The fans at the highest level (lf=4) were significantly effective in improving whole-body and local thermal sensations when compared to fan-off, at all M levels.
At the intermediate level (lf=2), the statistical significance varied with thermal zone, M and time interval considered.
The results of the simulations also showed that the Lower Torso needs to be monitored at M2 level, as the drop in skin temperature could lead to local overcooling and thermal discomfort.
Simulations showed the potential effectiveness of the ventilation jacket, but human trials are needed to verify its cooling power in real working conditions.
•Simulations on a sweating manikin to evaluate the effectiveness of a ventilation jacket.•A more evident impact on the mean skin temperature than on the rectal temperature.•Significant decrease in trunk skin temperatures: a greater drop recorded in the Back.•Significantly improved whole-body and local sensations at the highest fan velocity.•Lower Trunk temperature drop needs to be monitored: it can lead to thermal discomfort.