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Del Ferraro S, Falcone T, Morabito M, Bonafede M, Marinaccio A, Gao C, Molinaro V. 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. J Therm Biol 2024; 119:103772. [PMID: 38145612 DOI: 10.1016/j.jtherbio.2023.103772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/20/2023] [Accepted: 12/01/2023] [Indexed: 12/27/2023]
Abstract
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.
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Affiliation(s)
- Simona Del Ferraro
- Laboratory of Ergonomics and Physiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
| | - Tiziana Falcone
- Laboratory of Ergonomics and Physiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
| | - Marco Morabito
- Institute of BioEconomy (IBE), National Research Council, Via Madonna Del Piano 10, 50019, Sesto Fiorentino, FI, Italy; Centre of Bioclimatology, University of Florence, Piazzale Delle Cascine 18, 50144, Florence, Italy.
| | - Michela Bonafede
- Laboratory of Occupational and Environmental Epidemiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Stefano Gradi 55, 00143, Rome, Italy.
| | - Alessandro Marinaccio
- Laboratory of Occupational and Environmental Epidemiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Stefano Gradi 55, 00143, Rome, Italy.
| | - Chuansi Gao
- Aerosol and Climate Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Sölvegatan 26, Lund, Sweden.
| | - Vincenzo Molinaro
- Laboratory of Ergonomics and Physiology, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, INAIL, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
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Del Ferraro S, Falcone T, Morabito M, Messeri A, Bonafede M, Marinaccio A, Gao C, Molinaro V. A potential wearable solution for preventing heat strain in workplaces: The cooling effect and the total evaporative resistance of a ventilation jacket. Environ Res 2022; 212:113475. [PMID: 35588774 DOI: 10.1016/j.envres.2022.113475] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/04/2022] [Accepted: 05/11/2022] [Indexed: 05/14/2023]
Abstract
The increase in average seasonal temperatures has an impact in the occupational field, especially for those sectors whose work activities are performed outdoors (agricultural, road and construction sectors). Among the adaptation measures and solutions developed to counteract occupational heat strain, personal cooling garments represent a wearable technology designed to remove heat from the human body, enhancing human performance. This study aims to investigate the effectiveness and the cooling power of a specific cooling garment, i.e. a ventilation jacket, by quantifying the evaporative heat losses and the total evaporative resistance both when worn alone and in combination with a work ensemble, at three adjustments of air ventilation speed. Standardised "wet" tests in a climatic chamber were performed on a sweating manikin in isothermal conditions considering three clothing ensembles (single jacket, work ensemble and a combination of both) and three adjustments of fan velocity. Results showed a significant increase (p < 0.001) in evaporative heat loss values when the fan velocity increased, particularly within the trunk zones for all the considered clothing ensembles, showing that fans enhanced the dissipation by evaporation. The cooling power, quantified in terms of percent changes of evaporative heat loss, showed values exceeding 100% when fans were on, in respect to the condition of fans-off, for the trunk zones except for the Chest. A significant (p < 0.01) decrease (up to 42.3%) in the total evaporative resistance values of the jacket, coupled with the work ensemble, was found compared to the fans-off condition. Results confirmed and quantified the cooling effect of the ventilation jacket which enhanced the evaporative heat losses of the trunk zones, helping the body to dissipate heat and showing the potential for a heat adaptation measure to be developed.
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Affiliation(s)
- Simona Del Ferraro
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Laboratory of Ergonomics and Physiology, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
| | - Tiziana Falcone
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Laboratory of Ergonomics and Physiology, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy; Unit of Advanced Robotics and Human-Centred Technologies, Campus Bio-Medico University of Rome, Rome, Italy.
| | - Marco Morabito
- Institute of BioEconomy (IBE), National Research Council, Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy; Centre of Bioclimatology, University of Florence, Piazzale delle Cascine 18, 50144, Florence, Italy.
| | - Alessandro Messeri
- Tuscany Region, LaMMA Consortium - Weather Forecaster and Researcher at Laboratory of Monitoring and Environmental Modelling for Sustainable Development, 50019, Sesto Fiorentino, Florence, Italy; Fondazione per il Clima e la Sostenibilità, Via G.Caproni 8, 50145, Florence, Italy.
| | - Michela Bonafede
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Laboratory of Occupational and Environmental Epidemiology, Via Stefano Gradi 55, 00143, Rome, Italy.
| | - Alessandro Marinaccio
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Laboratory of Occupational and Environmental Epidemiology, Via Stefano Gradi 55, 00143, Rome, Italy.
| | - Chuansi Gao
- Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund, Sweden.
| | - Vincenzo Molinaro
- INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Laboratory of Ergonomics and Physiology, Via Fontana Candida 1, 00078, Monte Porzio Catone, Rome, Italy.
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Wang F, Lai D, Shi W, Fu M. Effects of fabric thickness and material on apparent 'wet' conductive thermal resistance of knitted fabric 'skin' on sweating manikins. J Therm Biol 2017; 70:69-76. [PMID: 29074028 DOI: 10.1016/j.jtherbio.2017.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 03/10/2017] [Accepted: 03/13/2017] [Indexed: 10/19/2022]
Abstract
Currently, no published standard and research work have addressed the basic requirements on knitted fabric 'skin' on sweating manikins. In this study, we performed 252 experiments to investigate the influence of fabric thickness and material on the apparent 'wet' conductive (or effective) thermal resistance of the fabric 'skin' using a 'Newton' manikin. Four types of cotton fabric 'skin' (fabric thickness: 0.38, 0.54, 0.92 and 1.43mm) and three types of polyester fabric 'skin' (fabric thickness: 0.41, 0.54 and 1.0mm) were selected and their 'wet' conductive thermal resistance was determined. Empirical equations were also developed for each fabric 'skin' to predict wet fabric 'skin' surface temperatures. It was found that both fabric thickness and material significantly affected the apparent 'wet' conductive thermal resistance. Clothing total evaporative resistance determined using thin fabric 'skin' (e.g., CO1, CO2) was normally lower than that determined using thick fabric 'skin' (e.g., CO4). Besides, synthetic fabric 'skin' tended to have a larger apparent 'wet' conductive thermal resistance than the cotton fabric 'skin' due to a smaller amount of moisture contained. Hence, there is a great need to standardize the fabric 'skin' to eliminate the influence of fabric 'skin' on the measurement of clothing evaporative resistance by means of a sweating manikin.
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Affiliation(s)
- Faming Wang
- Institute of Textiles and Clothing, ST706, ITC, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
| | - Dandan Lai
- Laboratory for Clothing Physiology and Ergonomics (LCPE), Soochow University, China
| | - Wen Shi
- Laboratory for Clothing Physiology and Ergonomics (LCPE), Soochow University, China
| | - Ming Fu
- Hefei Institute for Public Safety Research, Tsinghua University, China
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Lu Y, Wang F, Peng H, Shi W, Song G. Effect of sweating set rate on clothing real evaporative resistance determined on a sweating thermal manikin in a so-called isothermal condition (T manikin = T a = T r). Int J Biometeorol 2016; 60:481-488. [PMID: 26150329 DOI: 10.1007/s00484-015-1029-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 04/17/2015] [Accepted: 06/19/2015] [Indexed: 06/04/2023]
Abstract
The ASTM F2370 (2010) is the only standard with regard to measurement of clothing real evaporative resistance by means of a sweating manikin. However, the sweating set-point is not recommended in the standard. In this study, the effect of sweating rate on clothing real evaporative resistance was investigated on a 34-zone "Newton" sweating thermal manikin in a so-called isothermal condition (T manikin = T a = T r). Four different sweating set rates (i.e., all segments had a sweating rate of 400, 800, 1200 ml/hr ∙ m(2), respectively, and different sweating rates were assigned to different segments) were applied to determine the clothing real evaporative resistance of five clothing ensembles and the boundary air layer. The results indicated that the sweating rate did not affect the real evaporative resistance of clothing ensembles with the absence of strong moisture absorbent layers. For the clothing ensemble with tight cotton underwear, a sweating rate of lower than 400 ml/hr ∙ m(2) is not recommended. This is mainly because the wet fabric "skin" might not be fully saturated and thus led to a lower evaporative heat loss and thereby a higher real evaporative resistance. For vapor permeable clothing, the real evaporative resistance determined in the so-called isothermal condition should be corrected before being used in thermal comfort or heat strain models. However, the reduction of wet thermal insulation due to moisture absorption in different test scenarios had a limited contribution to the effect of sweating rate on the real evaporative resistance.
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Affiliation(s)
- Yehu Lu
- Laboratory for Clothing Physiology and Ergonomics (LCPE), The National Engineering Laboratory for Modern Silk, Soochow University, 199 Ren'ai Road, Suzhou, 215123, JiangSu, People's Republic of China
| | - Faming Wang
- Laboratory for Clothing Physiology and Ergonomics (LCPE), The National Engineering Laboratory for Modern Silk, Soochow University, 199 Ren'ai Road, Suzhou, 215123, JiangSu, People's Republic of China.
| | - Hui Peng
- Laboratory for Clothing Physiology and Ergonomics (LCPE), The National Engineering Laboratory for Modern Silk, Soochow University, 199 Ren'ai Road, Suzhou, 215123, JiangSu, People's Republic of China
| | - Wen Shi
- Laboratory for Clothing Physiology and Ergonomics (LCPE), The National Engineering Laboratory for Modern Silk, Soochow University, 199 Ren'ai Road, Suzhou, 215123, JiangSu, People's Republic of China
| | - Guowen Song
- Department of AESHM, Iowa State University, Ames, IA, 50011, USA
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Pang TY, Subic A, Takla M. Evaluation of thermal and evaporative resistances in cricket helmets using a sweating manikin. Appl Ergon 2014; 45:300-307. [PMID: 23664244 DOI: 10.1016/j.apergo.2013.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 11/17/2012] [Accepted: 04/11/2013] [Indexed: 06/02/2023]
Abstract
The main objective of this study is to establish an approach for measuring the dry and evaporative heat dissipation cricket helmets. A range of cricket helmets has been tested using a sweating manikin within a controlled climatic chamber. The thermal manikin experiments were conducted in two stages, namely the (i) dry test and (ii) wet test. The ambient air temperature for the dry tests was controlled to ~ 23 °C, and the mean skin temperatures averaged ~ 35 °C. The thermal insulation value measured for the manikin with helmet ensemble ranged from 1.0 to 1.2 clo. The results showed that among the five cricket helmets, the Masuri helmet offered slightly more thermal insulation while the Elite helmet offered the least. However, under the dry laboratory conditions and with minimal air movement (air velocity = 0.08 ± 0.01 ms(-1)), small differences exist between the thermal resistance values for the tested helmets. The wet tests were conducted in an isothermal condition, with an ambient and skin mean temperatures averaged ~ 35 °C, the evaporative resistance, Ret, varied between 36 and 60 m(2) Pa W(-1). These large variations in evaporative heat dissipation values are due to the presence of a thick layer of comfort lining in certain helmet designs. This finding suggests that the type and design of padding may influence the rate of evaporative heat dissipation from the head and face; hence the type of material and thickness of the padding is critical for the effectiveness of evaporative heat loss and comfort of the wearer. Issues for further investigations in field trials are discussed.
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Affiliation(s)
- Toh Yen Pang
- School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Bundoora, VIC 3083, Australia.
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