Air and water perfusion-based personal cooling systems (PCSs) to protect against heat stress in protective clothing

2014 ◽  
pp. 296-315 ◽  
Author(s):  
M. Morrissey ◽  
F. Wang
Keyword(s):  
Heat Stress ◽  
Protective Clothing ◽  
Cooling Systems ◽  
Personal Cooling

The effect of personal cooling systems on performance under heat stress

1982 ◽  
Author(s):  
Dan Zakay ◽  
Yair Shapiro ◽  
Yoram Epstein ◽  
Shay Bril
Keyword(s):  
Heat Stress ◽  
Cooling Systems ◽  
Personal Cooling

scholarly journals An Evaluation of Personal Cooling Systems for Reducing Thermal Strain Whilst Working in Chemical/Biological Protective Clothing

2019 ◽  
Vol 10 ◽  
Author(s):  
Aaron J. E. Bach ◽  
Matthew J. Maley ◽  
Geoffrey M. Minett ◽  
Stephanie A. Zietek ◽  
Kelly L. Stewart ◽  
...  
Keyword(s):  
Protective Clothing ◽  
Thermal Strain ◽  
Cooling Systems ◽  
Personal Cooling

The Effect of Personal Cooling Systems on Performance under Heat Stress

1982 ◽  
Vol 26 (2) ◽  
pp. 128-131
Author(s):  
Dan Zakay ◽  
Yair Shapiro ◽  
Yoram Epstein ◽  
Shay Bril
Keyword(s):  
Heat Stress ◽  
Future Development ◽  
Cooling System ◽  
Stress Conditions ◽  
Cooling Systems ◽  
The Future ◽  
Severe Heat Stress ◽  
Fan Cooling ◽  
Personal Cooling

The effect of personal cooling systems on performance under heat stress was examined. Nine subjects were tested in severe heat stress conditions with seven types of personal cooling systems. It was found that, excluding the fan cooling system, all personal cooling systems enabled better performance as compared to performance under heat stress conditions without such a system. However, differences on several parameters among the various cooling systems were found. These differences are analyzed and the future development of such systems is discussed.

scholarly journals Experiments on Energy-Efficient Evaporative Cooling Systems for Poultry Farm Application in Multan (Pakistan)

2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  
Keyword(s):  
Heat Stress ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Thermal Exposure ◽  
Climatic Conditions ◽  
The Body ◽  
Dew Point ◽  
Sweat Glands ◽  
Cooling Systems ◽  
Humidity Index

Poultry are one of the most vulnerable species of its kind once the temperature-humidity nexus is explored. This is so because the broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air. As a result, moisture production inside poultry house needs to be maintained to avoid any serious health and welfare complications. Several strategies such as compressor-based air-conditioning systems have been implemented worldwide to attenuate the heat stress in poultry, but these are not economical. Therefore, this study focuses on the development of low-cost and environmentally friendly improved evaporative cooling systems (DEC, IEC, MEC) from the viewpoint of heat stress in poultry houses. Thermodynamic analysis of these systems was carried out for the climatic conditions of Multan, Pakistan. The results appreciably controlled the environmental conditions which showed that for the months of April, May, and June, the decrease in temperature by direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and Maisotsenko-Cycle evaporative cooling (MEC) systems is 7–10 °C, 5–6.5 °C, and 9.5–12 °C, respectively. In case of July, August, and September, the decrease in temperature by DEC, IEC, and MEC systems is 5.5–7 °C, 3.5–4.5 °C, and 7–7.5 °C, respectively. In addition, drop in temperature-humidity index (THI) values by DEC, IEC, and MEC is 3.5–9 °C, 3–7 °C, and 5.5–10 °C, respectively for all months. Optimum temperature and relative humidity conditions are determined for poultry birds and thereby, systems’ performance is thermodynamically evaluated for poultry farms from the viewpoint of THI, temperature-humidity-velocity index (THVI), and thermal exposure time (ET). From the analysis, it is concluded that MEC system performed relatively better than others due to its ability of dew-point cooling and achieved THI threshold limit with reasonable temperature and humidity indexes.

Protective clothing and heat stress

Ergonomics ◽  
1995 ◽  
Vol 38 (1) ◽  
pp. 166-182 ◽  
Author(s):  
INGVAR HOLMÉR
Keyword(s):  
Heat Stress ◽  
Protective Clothing

Heat acclimation, aerobic fitness, and hydration effects on tolerance during uncompensable heat stress

1998 ◽  
Vol 84 (5) ◽  
pp. 1731-1739 ◽  
Author(s):  
Stephen S. Cheung ◽  
Tom M. McLellan
Keyword(s):  
Heart Rate ◽  
Heat Stress ◽  
Aerobic Fitness ◽  
Protective Clothing ◽  
Sweat Rate ◽  
Heat Acclimation ◽  
Short Term ◽  
Chemical Protective Clothing ◽  
Uncompensable Heat Stress ◽  
C 30

—The purpose of the present study was to determine the separate and combined effects of aerobic fitness, short-term heat acclimation, and hypohydration on tolerance during light exercise while wearing nuclear, biological, and chemical protective clothing in the heat (40°C, 30% relative humidity). Men who were moderately fit [(MF); <50 ml ⋅ kg−1 ⋅ min−1maximal O2 consumption; n = 7] and highly fit [(HF); >55 ml ⋅ kg−1 ⋅ min−1maximal O2 consumption; n = 8] were tested while they were euhydrated or hypohydrated by ∼2.5% of body mass through exercise and fluid restriction the day preceding the trials. Tests were conducted before and after 2 wk of daily heat acclimation (1-h treadmill exercise at 40°C, 30% relative humidity, while wearing the nuclear, biological, and chemical protective clothing). Heat acclimation increased sweat rate and decreased skin temperature and rectal temperature (Tre) in HF subjects but had no effect on tolerance time (TT). MF subjects increased sweat rate but did not alter heart rate, Tre, or TT. In both MF and HF groups, hypohydration significantly increased Tre and heart rate and decreased the respiratory exchange ratio and the TT regardless of acclimation state. Overall, the rate of rise of skin temperature was less, while ΔTre, the rate of rise of Tre, and the TT were greater in HF than in MF subjects. It was concluded that exercise-heat tolerance in this uncompensable heat-stress environment is not influenced by short-term heat acclimation but is significantly improved by long-term aerobic fitness.

Modeling heat stress and heat strain in protective clothing

2014 ◽  
pp. 416-434 ◽  
Author(s):  
P. Bishop ◽  
K. Crew ◽  
J. Wingo ◽  
A. Nawaiseh
Keyword(s):  
Heat Stress ◽  
Protective Clothing ◽  
Heat Strain

Development of a Cooling Garment With Encapsulated PCM

2000 ◽  
Author(s):  
David P. Colvin ◽  
Virginia S. Colvin ◽  
Yvonne G. Bryant ◽  
Linda G. Hayes ◽  
Michael A. Spieker
Keyword(s):  
Heat Stress ◽  
Phase Change ◽  
Protective Clothing ◽  
Environmental Control ◽  
Packed Bed ◽  
High Heat ◽  
Industrial Workers ◽  
Latent Heat Storage ◽  
Innovation Research ◽  
Cooling Garment

Abstract Under SBIR (Small Business Innovation Research) programs from the U.S. Marine Corps, investigators at Triangle Research and Development Corporation (TRDC) have conducted research toward the development of a unique passive cooling garment to provide significant microclimate cooling to Marines dressed in NBC (Nuclear/Biological/Chemical) protective clothing. The patented PECS (Protective Environmental Control System) garment utilizes 3–4 mm diameter macroencapsulated phase change material (macroPCM) particles distributed throughout a lightweight and highly breathable vest garment to provide 1–3 hours of cooling in high heat stress environments. With polymer walls encapsulating the paraffin PCM, the macroPCMs provide a wearable, packed bed heat exchanger that is flexible, highly breathable, and undergoes its solid/liquid phase change from 25–28°C, where its high latent heat storage can reach 60 calories/gram. This cooling range is at elevated and more comfortable temperatures than gel media used in other passive microclimate garments, which store their cold near 0°C and can cause shivering and discomfort. Although other microclimate garments require refrigeration or freezers to thermally recharge the cooling media, the passive 5-lb PECS cooling garment can be thermally recharged in the field at room temperatures (15–20°C) without refrigeration. Although earlier publications described the principles for such a cooling garment, this publication is the first to describe the garment’s construction, development and testing. Extensive laboratory testing has included Marine volunteers on a treadmill in a heated environmental chamber while dressed in Level IV MOPP and Level A protective clothing and a gas mask. PECS has also been used by costumed characters at Walt Disney World to provide extended cooling within an extended heat stress environment. Besides military uses, passive macroPCM garments should find other applications; including: protective clothing for firefighters, industrial workers, costumed characters and persons with heat stress disabilities.

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