Cooling effects of preferred air velocity in muggy conditions

Kubo, Hiroko; Isoda, Norio; Enomoto-Koshimizu, Hikaru

doi:10.1016/s0360-1323(96)00038-8

Cited by 44 publications

(14 citation statements)

References 5 publications

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“…These results suggest that at temperatures near 28 and 30°C air speeds of 1.8 m/s are practical, but may not be sufficient for the combination of 30°C /80% RH. The present results confirm previously findings that personally controlled air movement can maintain thermal comfort in warm-humid environments [18] [19]. The mean TS votes in the current study were mostly within the neutral to slightly-warm range at 28ºC and 30ºC (see Fig.5a), while in study [18] and [19], the subjects' TS were mostly on neutral to slightly cool range.…”

Section: 226supporting

confidence: 82%

“…The present results confirm previously findings that personally controlled air movement can maintain thermal comfort in warm-humid environments [18] [19]. The mean TS votes in the current study were mostly within the neutral to slightly-warm range at 28ºC and 30ºC (see Fig.5a), while in study [18] and [19], the subjects' TS were mostly on neutral to slightly cool range. The reasons may be that we used commercially available fans instead of fan-boxes producing air speed over a larger area of the body, and their subjects preferred slightly higher air speeds than our fans were capable of providing.…”

Section: 226supporting

confidence: 82%

“…One of these, by Tanabe and Kimura [18] tested horizontal air movement provided by an array of box fans on sedentary subjects wearing 0.6clo, and found that comfort could be maintained at 31°C, 50% RH with 1.6 m/s airspeed, and at 29°C, 80% RH with 1.4 m/s air speed. Kubo et al [19] tested self-selected frontal airflow with subjects wearing 0.35 clo at 30°C and 80% RH. Subjects chose a cooler-than-neutral thermal sensation by selecting an average air speed of 1.27 m/s at 30°C and 80% RH.…”

mentioning

confidence: 99%

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Comfort under personally controlled air movement in warm and humid environments

Zhai

Zhang

et al. 2013

Building and Environment

184

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This study examined the effects of personally controlled air movement on human thermal comfort and perceived air quality (PAQ) in warm-humid environments. At temperatures 26, 28, and 30°C, and relative humidity (RH) 60% and 80%, sixteen human subjects were exposed to personally controlled air movement provided by floor fans in an environmental chamber. The subjects reported their thermal sensation, thermal comfort, and PAQ during the tests. Two breaks periods with elevated metabolic levels were used to simulate normal office activities. Results show that with personally controlled air movement, thermal comfort could be maintained up to 30°C and 60% RH, and acceptable PAQ could be maintained up to 30°C 80% RH, without discomfort from humidity, air movement or eye-dryness. Thermal comfort and PAQ were resumed within 5 minutes after the breaks. The 80% acceptable limit implicit in comfort standards could be extended to 30°C and 60% RH. The average energy consumed by the fans for maintaining comfort was lower than 10W per person, making air movement a very energy-efficient way to deliver comfort in warm-humid environments.

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Section: 226supporting

confidence: 82%

Section: 226supporting

confidence: 82%

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confidence: 99%

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Comfort under personally controlled air movement in warm and humid environments

Zhai

Zhang

et al. 2013

Building and Environment

184

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“…In most sleep studies, the environment is defined by its Ta. Several studies have examined the effects of airflow in awake people regarding thermal sensation, thermal comfort, and body temperature (Tanabe and Kimura 1989;Adams et al 1992;Kubo et al 1997). Airflow decreases both the Ts and sweat rate by increasing convective heat loss (Adams et al 1992) and improving thermal sensation and thermal comfort under warm humid conditions (Tanabe and Kimura 1989; Kubo et al 1997).…”

Section: Introductionmentioning

confidence: 98%

Effects of airflow on body temperatures and sleep stages in a warm humid climate

et al. 2007

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Airflow is an effective way to increase heat loss-an ongoing process during sleep and wakefulness in daily life. However, it is unclear whether airflow stimulates cutaneous sensation and disturbs sleep or reduces the heat load and facilitates sleep. In this study, 17 male subjects wearing short pyjamas slept on a bed with a cotton blanket under two of the following conditions: (1) air temperature (Ta) 26 degrees C, relative humidity (RH) 50%, and air velocity (V) 0.2 m s(-1); (2) Ta 32 degrees C, RH 80%, V 1.7 m s(-1); (3) Ta 32 degrees C; RH 80%, V 0.2 m s(-1) (hereafter referred to as 26/50, 32/80 with airflow, and 32/80 with still air, respectively). Electroencephalograms, electrooculograms, and mental electromyograms were obtained for all subjects. Rectal (Tre) and skin (Ts) temperatures were recorded continuously during the sleep session, and body-mass was measured before and after the sleep session. No significant differences were observed in the duration of sleep stages between subjects under the 26/50 and 32/80 with airflow conditions; however, the total duration of wakefulness decreased significantly in subjects under the 32/80 with airflow condition compared to that in subjects under the 32/80 with still air condition (P<0.05). Tre, Tsk, Ts, and body-mass loss under the 32/80 with airflow condition were significantly higher compared to those under the 26/50 condition, and significantly lower than those under the 32/80 with still air condition (P<0.05). An alleviated heat load due to increased airflow was considered to exist between the 32/80 with still air and the 26/50 conditions. Airflow reduces the duration of wakefulness by decreasing Tre, Tsk, Ts, and body-mass loss in a warm humid condition.

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“…from 20 o C to 34 o C [10]), moderate metabolic rate level [11][12][13] (e.g. from 0.95met to 2.94met [13]) and air velocity range [14,15] (e.g. from 0.7m/s to 1.4m/s [15] ), etc.…”

Section: Introductionmentioning

confidence: 99%

A modified method of evaluating the impact of air humidity on human acceptable air temperatures in hot-humid environments

Ming

et al. 2018

Energy and Buildings

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R. (2018) A modified method of evaluating the impact of air humidity on human acceptable air temperatures in hothumid environments. Energy and Buildings, 158. pp. 393405. ISSN 03787788 Abstract: This research aims to investigate human thermal responses to air humidity in warm and hot environments and to evaluate the effect of humidity on human thermal comfort. 20 subjects were involved in 12 exposure experiments in a well-controlled climate chamber at three relative humidity levels (40%RH, 60%RH, 80%RH) and four air temperature levels (26°C, 28°C, 30°C, 32°C) with no much indoor airflow. The physical environmental and physiological parameters as well as subjective questionnaires were collected simultaneously during the period of experiments. The results show that in hot environments, particularly when the air temperature exceeds 30°C, the relative humidity has a significant effect on human thermal responses both physiologically and subjectively. The Standard Effective Temperature (SET) is biased when evaluating human thermal comfort in the hot-humid environments without considering human thermal adaptation to humidity. Hence, a humidity correction coefficient eRH is proposed to modify the deviation of the SET under different relative humidity levels, and to quantify the effect of humidity on human acceptable air temperatures. The modified acceptable temperature-humidity zone has been obtained using the modified method.

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Cooling effects of preferred air velocity in muggy conditions

Cited by 44 publications

References 5 publications

Comfort under personally controlled air movement in warm and humid environments

Comfort under personally controlled air movement in warm and humid environments

Effects of airflow on body temperatures and sleep stages in a warm humid climate

A modified method of evaluating the impact of air humidity on human acceptable air temperatures in hot-humid environments

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