scholarly journals A new method for evaluating the joint effect of draught and the hot ceiling

2020 ◽  
pp. 102-102
Author(s):  
Balázs András-Tövissi ◽  
László Kajtár ◽  
József Nyers
Keyword(s):  
Mechanical Ventilation ◽  
Thermal Comfort ◽  
Mathematical Description ◽  
Human Subject ◽  
Thermal Sensation ◽  
Joint Effect ◽  
Combined Effect ◽  
New Method ◽  
Random Combination

For buildings with ceiling heating and mechanical ventilation, it is extremely important to know the combined effect of the draught and the radiant thermal asymmetry caused by a warm ceiling. There is plenty of literature offering separate descriptions of the dissatisfaction caused by draught and warm ceilings, but research on the combined effect of these two local discomfort factors is incomplete. In order to fill in this gap, human subject measurements were conducted involving 20 subjects, 10 men and 10 women, who were asked to complete questionnaires on thermal sensation, while being exposed to a random combination of 5 asymmetries and 2 draughts. Analyzing the results obtained this way made it possible to evaluate the combined effect of the draught and radiant thermal asymmetry on thermal comfort. The most important outcome of the research is the mathematical description of the expected dissatisfaction rate and the presentation of the differences depending on gender.

scholarly journals A New Method to Describe the Combined Effect of Draught and Radiant Thermal Asymmetry on Human Work Performance

2020 ◽  
Vol 28 (2) ◽  
pp. 43-49
Author(s):  
Balázs András-Tövissi ◽  
László Kajtár
Keyword(s):  
Human Resources ◽  
Thermal Comfort ◽  
Human Subject ◽  
Work Performance ◽  
Joint Effect ◽  
Combined Effect ◽  
New Method ◽  
Work Efficiency ◽  
Crucial Importance ◽  
Thermal Environments

AbstractHuman resources are the most important elements of economic units; thus, the efficiency of human work is of crucial importance. Work efficiency can be achieved only in an environment offering optimal thermal comfort. The present study makes use of human subject experiments in order to investigate the joint effect of draughts and warm ceilings on work performance. During the experiments, 10 thermal environments with 5 radiant thermal asymmetries and 2 draught rates were investigated. The most important outcome of the research is the presentation of the combined effect of a draught and a warm ceiling on work performance.

Influence of sinusoidal airflow and airflow distance on human thermal response to a personalized ventilation system

2016 ◽  
Vol 27 (3) ◽  
pp. 317-330 ◽  
Author(s):  
Yongxin Xie ◽  
Sauchung Fu ◽  
Chili Wu ◽  
Christopher Y.H. Chao
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Human Subjects ◽  
Ventilation System ◽  
Thermal Response ◽  
Joint Effect ◽  
Experimental Conditions ◽  
Movement Perception ◽  
Air Movement ◽  
Personalized Ventilation

Since the concept of personalized ventilation was introduced in the late 1990s, many studies on thermal comfort have been conducted and a number of parameters identified. In this research, the influence of three parameters, the airflow speed, airflow fluctuating period and a parameter which has drawn less attention in previous studies – the airflow distance between the human subject and the nozzle of the personalized ventilation device on air movement perception, thermal sensation and thermal comfort – are studied. The combinations of fluctuating period and airflow amplitude were selected based on the Power Spectrum Density method. Then 25 human subjects participated in the thermal comfort experiment, each of them underwent 54 tests of different experimental conditions and expressed their thermal feelings by completing the survey questionnaire. Our findings showed that a longer airflow distance could lead to cooler thermal sensation, but not cause any difference in thermal comfort. Changing the fluctuating period of the sinusoidal airflow from 10 s to 60 s did not cause an influence on thermal sensation, but a shorter fluctuating period could result in a higher air movement perception. When dealing with thermal comfort issues, a joint effect with airflow speed and fluctuating period occurs and this should also be considered.

Thermal Comfort and Thermal Sensation During Exposure to Hot, Hot-Humid and Thermoneutral Environments

1998 ◽  
Author(s):  
Margaret A. Kolka ◽  
Christina M. Kesick ◽  
Leslie Levine ◽  
Sharon A. McBride ◽  
Lou A. Stephenson
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation

scholarly journals Combined effect of hypertension and hyperuricemia on ischemic stroke in a rural Chinese population

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peng Sun ◽  
Mengqi Chen ◽  
Xiaofan Guo ◽  
Zhao Li ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Missing Data ◽  
Chinese Population ◽  
Joint Effect ◽  
Cross Sectional Study ◽  
Combined Effect ◽  
Sectional Study ◽  
Cross Sectional ◽  
Current Smoking ◽  
Positive Correlations

Abstract Background To investigate the combined effect of hypertension and hyperuricemia to the risk of ischemic stroke in a rural Chinese population. Methods The cross-sectional study was conducted from 2012 to 2013 in a rural area of China. After exclusion for missing data, we finally included 11,731 participants into analysis. Results After adjusting for age, current smoking, current drinking, BMI, TG, HDL-C and eGFR, hypertension was significantly associated with ischemic stroke in men (OR: 2.783, 95% CI: 1.793, 4.320) and in women (OR: 4.800, 95% CI: 2.945, 7.822). However, hyperuricemia was significantly associated with ischemic stroke only in women (OR: 1.888, 95% CI: 1.244, 2.864). After full adjustment, participants with both hypertension and hyperuricemia had 8.9 times higher risk than those without them. Finally, the interaction between hypertension and hyperuricemia was statistically significant only in women rather than in men after full adjustment. Conclusions This study demonstrated the positive correlations between hypertension, hyperuricemia and ischemic stroke. Our study also demonstrated the joint effect between hypertension and hyperuricemia towards ischemic stroke only in women, not in men.

scholarly journals Proposal of Relative Thermal Sensation: Another Dimension of Thermal Comfort and Its Investigation

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 36266-36281
Author(s):  
Ziyang Wang ◽  
Hiroshi Onodera ◽  
Ryuji Matsuhashi
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation

scholarly journals Thermal Comfort and Sleep Quality of Indonesian Students Living in Japan during Summer and Winter

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 326
Author(s):  
Wiwik Budiawan ◽  
Kazuyo Tsuzuki
Keyword(s):  
Sleep Quality ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Thermal Conditions ◽  
Physical Conditions ◽  
Subjective Sleepiness ◽  
Adaptive Action ◽  
Quality Sleep ◽  
Sleep Parameters

Thermal comfort is crucial in satisfaction and maintaining quality sleep for occupants. In this study, we investigated the comfort temperature in the bedroom at night and sleep quality for Indonesian students during summer and winter. Eighteen male Indonesian students aged 29 ± 4 years participated in this study. The participants had stayed in Japan for about six months. We evaluated the sleep parameters using actigraphy performed during summer and winter. All participants completed the survey regarding thermal sensation, physical conditions, and subjective sleepiness before sleep. The temperature and relative humidity of participants’ bedrooms were also measured. We found that the duration on the bed during winter was significantly longer than that during summer. However, sleeping efficiency during winter was significantly worse than that during summer. The bedroom temperature of the participants was in the range of comfort temperature in Indonesia. With the average bedroom air temperature of 22.2 °C, most of the participants still preferred “warm” and felt “slightly comfortable” during winter. The average comfort temperature each season calculated using the Griffiths method was 28.1 °C during summer and 23.5 °C during winter. In conclusion, differences in adaptive action affect bedroom thermal conditions. Furthermore, habits encourage the sleep performance of Indonesian students.

scholarly journals Predicted Medium Vote Thermal Comfort Analysis Applying Energy Simulations with Phase Change Materials for Very Hot-Humid Climates in Social Housing in Ecuador

2021 ◽  
Vol 13 (3) ◽  
pp. 1257
Author(s):  
Luis Godoy-Vaca ◽  
E. Catalina Vallejo-Coral ◽  
Javier Martínez-Gómez ◽  
Marco Orozco ◽  
Geovanna Villacreses
Keyword(s):  
Thermal Comfort ◽  
Phase Change ◽  
Social Housing ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Thermal Sensation ◽  
Electricity Consumption ◽  
Different Types ◽  
Climate Influences ◽  
Energy Simulations

This work aims to estimate the expected hours of Predicted Medium Vote (PMV) thermal comfort in Ecuadorian social housing houses applying energy simulations with Phase Change Materials (PCMs) for very hot-humid climates. First, a novel methodology for characterizing three different types of social housing is presented based on a space-time analysis of the electricity consumption in a residential complex. Next, the increase in energy demand under climate influences is analyzed. Moreover, with the goal of enlarging the time of thermal comfort inside the houses, the most suitable PCM for them is determined. This paper includes both simulations and comparisons of thermal behavior by means of the PMV methodology of four types of PCMs selected. From the performed energy simulations, the results show that changing the deck and using RT25-RT30 in walls, it is possible to increase the duration of thermal comfort in at least one of the three analyzed houses. The applied PCM showed 46% of comfortable hours and a reduction of 937 h in which the thermal sensation varies from “very hot” to “hot”. Additionally, the usage time of air conditioning decreases, assuring the thermal comfort for the inhabitants during a higher number of hours per day.

Experimental study of the influence of anticipated control on human thermal sensation and thermal comfort

Indoor Air ◽  
2013 ◽  
Vol 24 (2) ◽  
pp. 171-177 ◽  
Author(s):  
X. Zhou ◽  
Q. Ouyang ◽  
Y. Zhu ◽  
C. Feng ◽  
X. Zhang
Keyword(s):  
Experimental Study ◽  
Thermal Comfort ◽  
Thermal Sensation
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