A Novel Hybrid Personal Cooling System Incorporated with Dry Ice and Ventilation Fans to Mitigate the Heat Strain of Mascot Actors in a Hot and Humid Environment

AbstractA review of the literature on heat strain and aircrew and a questionnaire survey of Royal Navy aircrew have been completed. Aircrew appreciate, some 50% from first hand experience, that heat strain can reduce their operational endurance and performance. They are at greatest risk of developing it in the pre-flight period, especially when wearing Nuclear, Biological, or Chemical (NBC) protective equipment. Several techniques they use to reduce this risk are described. Some may be of particular assistance in the field should air conditioned facilities be unavailable. However, opportunities to improve the thermal environment within the aircraft on the ground and in flight are limited as the heat generated within it and high levels of solar radiation impinging on it severely challenge air conditioning units, themselves constrained by weight and size. Other demands placed on protective clothing offer little potential to increase the rate at which aircrew can lose accumulated heat. It is concluded that an appropriate micro-climate cooling system worn next to the skin may be required to achieve truly significant reductions in heat strain. Research at the Institute of Naval Medicine has identified liquid cooling techniques which may be suitable for aircrew in all but the smallest helicopters.Any views expressed are those of the author and do not necessarily represent those of the Department.

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Development of a Prototype Personal Cooling System for First Responders: User Feedback

Journal of ASTM International ◽

10.1520/jai12105 ◽

2005 ◽

Vol 2 (2) ◽

pp. 12105 ◽

Cited By ~ 4

Author(s):

DH Branson ◽

CA Farr ◽

S Peksoz ◽

J Nam ◽

H Cao

Keyword(s):

Cooling System ◽

First Responders ◽

User Feedback ◽

Personal Cooling

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Experimental study on heat transfer characteristics of CNTs/Al 2 O 3 nanofluids in personal cooling system based on thermoelectric refrigeration

Procedia Engineering ◽

10.1016/j.proeng.2017.10.421 ◽

2017 ◽

Vol 205 ◽

pp. 588-595 ◽

Cited By ~ 1

Author(s):

Lian Duan ◽

Jitian Han ◽

Linlin Cao ◽

Chong Huo

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Cooling System ◽

Heat Transfer Characteristics ◽

Transfer Characteristics ◽

Thermoelectric Refrigeration ◽

Personal Cooling

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Evaluation of the ventilation unit for personal cooling system (PCS)

International Journal of Industrial Ergonomics ◽

10.1016/j.ergon.2017.02.009 ◽

2017 ◽

Vol 58 ◽

pp. 62-68 ◽

Cited By ~ 11

Author(s):

Wen Yi ◽

Yijie Zhao ◽

Albert P.C. Chan

Keyword(s):

Cooling System ◽

Personal Cooling

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Evaluation of a hybrid personal cooling system using a manikin operated in constant temperature mode and thermoregulatory model control mode in warm conditions

Textile Research Journal ◽

10.1177/0040517515622152 ◽

2016 ◽

Vol 87 (1) ◽

pp. 46-56 ◽

Cited By ~ 16

Author(s):

Dandan Lai ◽

Fanru Wei ◽

Yehu Lu ◽

Faming Wang

Keyword(s):

Cooling Rate ◽

Constant Temperature ◽

Cooling System ◽

Cooling Effect ◽

Control Mode ◽

Air Velocity ◽

Work Condition ◽

Model Control ◽

Thermoregulatory Model ◽

Personal Cooling

In this study, the cooling effect of a portable hybrid personal cooling system (PCS) was investigated on a sweating manikin operated in the constant temperature (CT) mode and the thermoregulatory model control (TMC) mode. Both dry (i.e., no sweating) and wet manikin tests (i.e., sweating) were performed in the CT mode in a warm condition (30℃, 47% relative humidity (RH), air velocity va = 0.4 m/s). For the TMC mode, two case studies were simulated: light work condition (30℃, 47% RH, air velocity va = 0.15 m/s, duration: 60 min, metabolic rate: 1.5 METs) and construction work condition (30℃, 47% RH, va = 1.0 m/s, 40 min exercise [5.5 METs] and 20 min rest [1.2 METs]). Four test scenarios were selected: fans off with no phase change materials (PCMs) (i.e., Fan-off, the Control), fans on with no PCMs (i.e., Fan-on), fans off with fully solidified PCMs (i.e., PCM+Fan-off) and fans on with fully solidified PCMs (i.e., PCM+Fan-on). Under the dry condition, the cooling rate in PCM+Fan-off during the initial stage (e.g., 55 and 50 W for the first 15 min and 20 min, respectively) was higher than that in Fan-on (i.e., 45 ± 1 W); under the wet condition, the cooling rate in PCM+Fan-off (e.g., 45 W for 10 min) was much lower than that in Fan-on (i.e., 282 ± 1 W). The hybrid PCS (i.e., PCM+Fan-on) provided a continuous strong cooling effect. Simulation results indicated that ventilation fans or PCMs alone could provide sufficient cooling while doing light work. For the intensive work condition, the PCS in all three scenarios (i.e., PCM+Fan-off, Fan-on and PCM+Fan-on) exhibited beneficial cooling, and the hybrid PCS showed an optimized performance in alleviating heat strain during both exercise and recovery periods. It was thus concluded that the PCS could effectively remove body heat in warm conditions for moderate intensive activities.

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Numerical Analysis on the Cooling Performance of a Hybrid Personal Cooling System (HPCS) under Different Hot Environments

10.20944/preprints201812.0034.v1 ◽

2018 ◽

Author(s):

Zhanxiao Kang ◽

Xianfu Wan ◽

Faming Wang ◽

Uday Raj ◽

Bin Yang

Keyword(s):

Relative Humidity ◽

Thermal Performance ◽

Environmental Temperature ◽

Cooling System ◽

Cooling Performance ◽

Hot Environment ◽

Four Levels ◽

Hot Environments ◽

The Impact ◽

Personal Cooling

The hybrid personal cooling system (HPCS) consisted of ventilation fans and phase change materials (PCMs) covered with insulation pads is a promising wearable cooling system to mitigate heat strain and heat-related illnesses of occupational workers with heavy labor in hot environments. Effects of clothing characteristics (e.g., thermal resistance of insulation pads, latent heat and melting temperature of PCMs) on the thermal performance of the HPCS have been investigated in detail in our previous study. Apart from the aforementioned factors, environmental conditions, i.e., environmental temperature and relative humidity, also significantly affect the thermal performance of the HPCS. In this paper, a numerical parametric study was performed to investigate the effects of the environmental temperature and relative humidity (RH) on the thermal management of the HPCS. Five levels of air temperature under environmental RH=50% were chosen (i.e., 32, 34, 36, 38 and 40 ºC) to study the impact of environmental temperature on the HPCS’s cooling performance. In addition, four levels of environmental RH at ambient temperatures of 36 and 40 ºC were selected (i.e., 30, 50, 70 and 90%) to examine the effect of RH on cooling performance of the HPCS. Results show that high environmental temperatures could accelerate the PCM melting process and thereby weaken the cooling performance of HPCS. In the moderately hot environment (36 °C), the HPCS presented good cooling performance with the maximum core temperature at around 37.5 °C during excise when the ambient RH≤70%, whereas good cooling performance could be only seen under RH≤50% in the extremely hot environment (40 °C). Thus, it may be concluded that the maximum environmental RH for the HPCS exhibiting good cooling performance decreases with the increase in the environmental temperature.

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