Analyzing the Time-Varying Thermal Perception of Students in Classrooms and Its Influencing Factors from a Case Study in Xi’an, China

Owing to movement in the spatial environment and changes in activity levels, students’ thermal perception is time varying in classrooms throughout different periods of the day. However, previous studies have rarely considered the time-varying thermal perception in different periods of the day, which may cause discomfort for students and lead to energy wastage. Therefore, a study was conducted to investigate the time-varying thermal perception of students and its influencing factors in different classes of the day. In addition, the differences in students’ adaptive behaviors in different periods were also explored. A total of 578 university students were surveyed using questionnaire surveys during the heating season in Xi’an, China. The following results can be obtained: (1) The thermal sensation vote and thermal preference vote values in the afternoon were significantly higher than those in the morning. At the start of the first class in the morning/afternoon, the thermal sensation of the students had the highest sensitivity to outdoor temperature changes. (2) The students’ thermal perception was greatly affected by the preclass activity state at the start of the first class in the morning/afternoon. However, in other periods, the above phenomenon was not obvious. (3) In the afternoon, the frequency of clothing adjustment was greater than that in the morning, and this behavior would significantly affect the students’ thermal sensation. (4) Compared with the current classroom heating strategy, the heating strategy of dynamically adjusting the indoor set temperature according to the time-varying characteristics of the students can theoretically achieve energy savings of 25.6%.

APPRAISING INDOOR THERMAL PERCEPTION OF ELDERLY IN HOT CLIMATES: An experimental investigation of free-running residential aged care homes in Colombo

Rapid demographic transition with higher growth in ageing population demonstrate a major societal challenge in South Asia and Sri Lankans will age faster than other developing economies in the region. Climate shocks of people living in economically deprived countries will increase in future and elders are more vulnerable to the adverse effects of temperature extremes. The study experimentally investigated free-running residential care homes in hot climate of Colombo performing simultaneous personal monitoring and questionnaire surveys. Results explicitly prove overheated indoors with less air flow. Majority of elders confirmed thermally unacceptable interiors with warm thermal sensations and low air velocities of 0.1 to 0.29 m/s with predominant preference of more air movement proves inadequate passive airflow. A significant relationship between wind preference and presence of openings of their place of stay were evident. Staying away from a window or door instigated to practice a behavioural adaptation of moving towards transitional areas such as corridors, verandas, and outdoor spaces for more wind sensation. Since ageing is associated with physical inabilities and elders spend their life mostly in indoors, findings emphasize the importance of enhancing passive airflow and application of appropriate design strategies to ensure optimum air velocities and dispersion of airflow within interiors.

Sudomotor dysfunction in patients with gluten neuropathy

Background and aim Gluten neuropathy (GN) is a common neurological manifestation of gluten sensitivity (GS), characterized by serological evidence of GS, while other risk factors for developing neuropathy are absent. The degree of small fiber dysfunction in GN has not been studied in depth to date. Small fiber involvement may lead to pain, thermal perception abnormalities, and sweat gland dysfunction. Sudomotor innervation refers to the cholinergic innervation of the sympathetic nervous system through small fibers in the sweat glands. The aim of our study was to assess the sudomotor function of GN patients. Methods Patients with GN were recruited. Clinical and neurophysiological data were obtained. HLA-DQ genotyping was performed. The skin electrochemical conductance (ESC) was measured with SUDOSCANTM. Results Thirty-two patients (25 males, mean age 69.5±10.2 years) were recruited. Thirteen patients (40.6%) had abnormal sudomotor function of the hands. Sixteen patients (50%) had abnormal sudomotor function of the feet. Twenty-one patients (65.6%) had abnormal sudomotor function of either the hands or feet. Sudomotor dysfunction did not correlate with the type of neuropathy (length-dependent neuropathy or sensory ganglionopathy), gluten-free diet adherence, severity of neuropathy, and duration of disease or HLA-DQ genotype. No differences in the ESC were found between patients with painful and patients with painless GN. Conclusion Sudomotor dysfunction affects two-thirds of patients with GN. The lack of correlation between pain and sudomotor dysfunction suggests different patterns of small fiber involvement in patients with GN.

Verification of a Comfort-Enhanced Liquid Cooling Vest

Firefighter uniforms provide thermal protection and block radiant as well as high-temperature heat. However, they limit cooling and the dissipation of internal heat from the body. This study attempted to improve firefighter uniforms by developing and evaluating a comfortable and thermally balanced design. This study recruited six male college students for a within-subject comparison of vests with and without active liquid cooling. The participants used a questionnaire to report their comfort level in each body part while performing various motions. A biomechanical analysis was performed to objectively evaluate the comfort level of the cooling vest before and after the test. Subsequently, the participants’ blood pressure and ear as well as skin temperature were measured as they ran on a treadmill. The participants also responded to a questionnaire regarding their thermal perception. The results revealed that the cooling vest was comfortable and flexible. The data from the psychological questionnaire indicated that the participants were satisfied with the warmth, coolness, and other various aspects of the cooling vest. Moreover, the cooling vest positively affected the wearer’s microclimate and provided a comfortable thermal balance. The current findings demonstrate the feasibility of using human-factors-engineering-based objective verification methods for designing products.

Will correlated colour temperature affect peoples’ thermal sensation outside the laboratory?

Earlier studies have shown that low Correlated Color Temperature of lighting (CCT) may induce a warmer thermal sensation than high CCTs at the same ambient temperature. The current study investigated if the association between CCT and thermal sensation would persist when subjects worked on computers, were exposed for longer duration and when the study population included older subjects whose vision may have changed with age. The study was carried out in a climate chamber with controllable LED lighting and where CCT could be gradually changed. Generally, the association between CCT and thermal sensation was weak and not significant. However, at 22°C and short-term exposure, the results indicated that high CCT caused a cooler thermal sensation. This association disappeared with more prolonged exposure duration and when subjects worked on a computer. Comparison of responses to lighting exposure of the two groups of subjects with mean ages of 24 years and 44 years showed no difference in their perceived thermal sensation when the CCT was changed. However, the older group of subjects could not distinguish differences in CCTs above 4000 K. The findings suggest that the magnitude of the effect of lighting on thermal perception is modest and only visible under exceptional and tightly controlled conditions that do not mirror actual buildings.

The impact of daylight presence on cooling strategies: energy simulations of a test room in Austin, Texas, and Geneva, Switzerland

In order to understand how to reduce energy consumption in buildings, all factors affecting occupant comfort and behavior must be considered. Previous work from EPFL has elucidated the influence of daylight on thermal perception and its resulting potential to reduce cooling loads in a controlled test space in Geneva, Switzerland with three different illumination levels (130 lux, 600 lux, and 1400 lux) and under three different indoor air temperature levels (19°C, 23°C, 27°C). Occupants perceived the temperature as up to 2°C cooler when exposed to daylight, leading to reduced cooling loads. For climates with high cooling loads for much of the year, such as Austin, Texas, this reduction could yield significant benefits for low-energy building design. Simulations show the total amount of energy saved from adopting this strategy in Austin, Texas.

The thermal phenomena of Aceh tradisional house due to changes inform spatial planning, building materials and constructure structures

The development of science and technology has influenced the pattern of human life, especially the housing as the basic needs in human life. This can also be seen in the Acehnese people who have made changes to their traditional houses which will unwittingly have an impact on the thermal performance of the building.. This study observes the thermal perception of the occupants of the original and changing Aceh traditional houses, in the form of their responses or reactions in describing environmental conditions when the air temperature is hot, normal, or cold, which is carried out by distributing questionnaires. Measurements were made on traditional house buildings and their occupants for 7 (seven) days on each house. As a thermal reference for occupancy, air temperature conditions in buildings and rooms will be measured using a Thermo Hygrograph and a Sling Thermometer. The results of this study indicate that there is a change in the thermal perception of occupancy in the form of a comfort range and length of time when the building is inhabited, which is caused by changes made to the traditional house building, in the form of adding another room at the back without disturbing the main building (Rumoh Aceh) using other materials and different buildings structures (not a stilt house like the main building).