Holes in wrist patches improve wearing comfort

2019 ◽  
Vol 31 (4) ◽  
pp. 522-531
Author(s):  
Lisa Klous ◽  
Wouter Bergmann Tiest ◽  
Pim van Dorst ◽  
Matthijs van der Linde ◽  
Hein Daanen
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Design Methodology ◽  
Thermal Sensation ◽  
Ventral Side ◽  
Content Type ◽  
Percent Relative Humidity ◽  
C 30 ◽  
Small Holes ◽  
Wrist Bands

Purpose The purpose of this paper was to investigate whether small holes in an impermeable patch at the wrist improve perceived comfort during exercise. Design/methodology/approach Nine male participants participated in this study. During the experiment, participants cycled 60 W in a hot room (35°C, 30 percent relative humidity) while an impermeable 20 cm2 patch was located on the ventral side of one wrist and at the same time a patch of identical shape with 5 mm diameter holes (17.7 percent uncovered) on the other wrist. The participants could not see the patches. Participants were forced to choose which patch they perceived as more comfortable. Chest and arm skin temperature, thermal comfort, thermal sensation and wetness perception were assessed. Findings Participants preferred 5 mm holes over no holes (p=0.017). Chest skin temperature (p=0.018) but not arm skin temperature correlates with this preference. Thermal comfort, thermal sensation and wetness perception did not differ significantly between patches. It is concluded that patches with 5 mm holes are preferred over impermeable patches during work in the heat in particular when the torso skin is warm. Originality/value The wrist is a preferred location for smart wearables. Generally, wrist bands are made of air-impermeable materials leading to sensation of wetness and discomfort. This study has shown that manufacturers should consider to make small holes in their wrist bands to optimize wearing comfort.

Evaluation of compression-recovery and thermal characteristics of multilayer bedding textiles

2020 ◽  
Vol 32 (5) ◽  
pp. 631-643
Author(s):  
Sedat Özer ◽  
Yaşar Erayman Yüksel ◽  
Yasemin Korkmaz
Keyword(s):  
Thermal Conductivity ◽  
Sleep Quality ◽  
Thermal Comfort ◽  
Sleep Duration ◽  
Human Body ◽  
Design Methodology ◽  
Thermal Characteristics ◽  
Air Permeability ◽  
Content Type ◽  
Thermal Comfort Properties

PurposeDesign of bedding textiles that contact the human body affects the sleep quality. Bedding textiles contribute to comfort sense during the sleep duration, in addition to ambient and bed microclimate. The purpose of this study is to evaluate the effects of different layer properties on the compression recovery and thermal characteristics of multilayer bedding textiles.Design/methodology/approachIn this study, woven and knitted multilayer bedding textiles were manufactured from fabric, fiber, sponge and interlining, respectively. Different sponge thickness, fiber and interlining weight were used in the layers of samples. Later, the pilling resistance, compression and recovery, air permeability and thermal conductivity of multilayer bedding textiles were investigated.FindingsThe results indicated that samples with the higher layer weight and thickness provide better compression recovery and lower air permeability properties. It was also found that knitted surfaces show the higher air permeability than the woven surfaces depending on the fabric porosity. Layer properties have insignificant effect on the thermal conductivity values.Originality/valueWhile researchers mostly focus on thermal comfort properties of garments, there are limited studies about comfort properties of bedding textiles in the literature. Furthermore, compression recovery properties of bedding textiles have also a great importance in terms of comfort. Originality of this study is that these properties were analyzed together.

Evaluation of occupant's adaptive thermal comfort behaviour in naturally ventilated courtyard houses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peiman Pilechiha ◽  
Alireza Norouziasas ◽  
Hoorieh Ghorbani Naeini ◽  
Kasmir Jolma
Keyword(s):  
Thermal Comfort ◽  
Design Methodology ◽  
Construction Materials ◽  
Parametric Models ◽  
Content Type ◽  
Seasonal Movement ◽  
Indoor Thermal Comfort ◽  
Adaptive Thermal Comfort ◽  
Vernacular Buildings ◽  
Hourly Basis

PurposeIn vernacular buildings, many climatic and passive solutions have been used to create indoor thermal comfort. Seasonal occupant movement is an example of a traditional response to increasing thermal comfort. This article investigates the influence of these user behaviours on thermal comfort in courtyard houses.Design/methodology/approachParametric models of three different scenarios of courtyard houses are simulated. The courtyard houses are located in Shiraz, Iran, and share the same orientation and construction materials. To enhance the accuracy of the study, the indoor adaptive thermal comfort (ATC) analysis is performed with three different window-to-wall ratios (WWR) of 25, 50 and 75%. The ACT analysis is performed on an hourly basis for summer and winter scenarios.FindingsThe results demonstrate that the indoor ATC is 8.3% higher in winter than in the summer in the seasonal zones. During the summer, the amount of ATC is relatively sustained in all zones. Unlike common beliefs, seasonal movement can enhance the ATC, especially during winter, specifically in the northern part of the courtyard. In northern zones, the seasonal movement of occupants improves the indoor ATC from 10.1 to 23.7%, and in southern zones, the improvement is from 2.2 to 4.8%.Originality/valueThis research presents a new numerical investigation into occupants' seasonal movements in courtyard houses during summer and winter. It provides a precise pattern to show how much this seasonal movement can affect the habitant's ATC.

Thermal comfort analyses of naturally ventilated university classrooms

2016 ◽  
Vol 34 (4/5) ◽  
pp. 427-445 ◽  
Author(s):  
Baharuddin Hamzah ◽  
Muhammad Taufik Ishak ◽  
Syarif Beddu ◽  
Mohammad Yoenus Osman
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
National Standard ◽  
Content Type ◽  
Thermal Environments ◽  
Neutral Temperature ◽  
Radiant Temperature ◽  
University Classrooms

Purpose The purpose of this paper is to analyse thermal comfort and the thermal environment in naturally ventilated classrooms. Specifically, the aims of the study were to identify the thermal environment and thermal comfort of respondents in naturally ventilated university classrooms and compare them with the ASHRAE and Indonesian National Standard (SNI); to check on whether the predicted mean vote (PMV) model is applicable or not for predicting the thermal comfort of occupants in naturally ventilated university classrooms; and to analyse the neutral temperature of occupants in the naturally ventilated university classrooms. Design/methodology/approach The study was carried out at the new campus of Faculty of Engineering, Hasanuddin University, Gowa campus. A number of field surveys, which measured thermal environments, namely, air temperature, mean radiant temperature (MRT), relative humidity, and air velocity, were carried out. The personal activity and clothing properties were also recorded. At the same time, respondents were asked to fill a questionnaire to obtain their thermal sensation votes (TSV) and thermal comfort votes (TCV), thermal preference, and thermal acceptance. A total of 118 respondents participated in the study. Before the survey was conducted, a brief explanation was provided to the participants to ensure that they understood the study objectives and also how to fill in the questionnaires. Findings The results indicated that the surveyed classrooms had higher thermal environments than those specified in the well-known ASHRAE standard and Indonesian National Standard (SNI). However, this condition did not make respondents feel uncomfortable because a large proportion of respondents voted within the comfort zone (+1, 0, and −1). The predictive mean vote using the PMV model was higher than the respondents’ votes either by TSV or by TCV. There was a huge difference between neutral temperature using operative temperature (To) and air temperature (Ta). This difference may have been because of the small value of MRT recorded in the measured classrooms. Originality/value The research shows that the use of the PMV model in predicting thermal comfort in the tropic region might be misleading. This is because PMV mostly overestimates the TSV and TCV of the respondents. People in the tropic region are more tolerant to a higher temperature. On the basis of this finding, there is a need to develop a new thermal comfort model for university classrooms that is particularly optimal for this tropical area.

scholarly journals Thermal comfort, thermal sensation and skin temperature measurements using demand-controlled ventilation for individual cooling

2020 ◽  
Vol 172 ◽  
pp. 06001
Author(s):  
Håkon Solberg ◽  
Kari Thunshelle ◽  
Peter Schild
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Energy Demand ◽  
Thermal Sensation ◽  
Air Velocity ◽  
Climate Chamber ◽  
Biometric Data ◽  
Ongoing Research ◽  
Demand Controlled Ventilation ◽  
The Relationship

An increasing part of modern building's energy demand is due to cooling. An ongoing research project investigates the possibility to reduce the energy consumption from cooling by utilizing an individually controlled active ventilation diffuser mounted in the ceiling. This study looks at thermal sensation and thermal comfort for 21 test persons exposed to an innovative user controlled active ventilation valve, in a steady and thermally uniform climate chamber. Furthermore, the relationship between biometric data from the test persons skin temperature and sweat, and the test persons thermal sensation scores has been investigated. Each test person was exposed to three different room temperatures in the climate chamber, 24°C, 26°C and 28°C respectively, to simulate typical hot summer conditions in an office in Norway. At a room temperature of 26°C it was possible to achieve acceptable thermal comfort for most test persons with this solution, but higher air velocity than 0.75 m/s around the test persons bodies at room temperatures of 28°C is required to ensure satisfactory thermal comfort.

Performance analysis of PCM curtain for thermal comfort

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shubham Srivastava ◽  
Abhishek Srivastava ◽  
Sanya Jain ◽  
Nandan Kumar ◽  
Chandra Shekhar Malvi
Keyword(s):  
Thermal Comfort ◽  
Design Methodology ◽  
Phase Change Materials ◽  
Heat Exposure ◽  
Mean Square ◽  
Constant Heat ◽  
Content Type ◽  
One Dimensional ◽  
Simulation Results ◽  
Modelling Assumptions

Purpose This study aims to analyse the variations of thermal comfort inside a building space by using different curtains. Design/methodology/approach Phase change materials (PCMs) such as wax, sand and mixture of sand and wax were used with cotton curtain to compare the results of PCM curtains with the performance of normal cotton curtain against constant heat exposure. Heat exposure was provided with halogen to simulate the solar radiation. Further simulation was performed on ANSYS and experimental results were compared with the simulation results. In addition to this, the results were analysed for optimized performance by calculation root mean square error. Findings It was found that PCM used curtains that have better performance than normal curtain. Furthermore, sand curtain was proved as the best curtain and mixture of sand and wax curtain could replace the sand curtain where there is limitation of weight; also, there was less error between experimental and simulation was reported for sand curtain as compare to other curtains. Research limitations/implications Layers of different PCMs were used before cotton curtain and in modelling assumptions such as one-dimensional heat transfer, uniform thermal conductivity. Originality/value To the best of the authors’ knowledge, there is no such study that was performed earlier.

A numerical investigation on the impacts of voids combinations on natural ventilation of high-rise residential building

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hamza Laloui ◽  
Noor Hanita Abdul Majid ◽  
Aliyah Nur Zafirah Sanusi
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Design Methodology ◽  
Natural Ventilation ◽  
Residential Building ◽  
Air Velocity ◽  
Content Type ◽  
High Rise ◽  
Living Unit ◽  
Ventilation Performance

Purpose This paper aims to investigate the impacts of introducing voids combinations on natural ventilation performance in high-rise residential building living unit. Design/methodology/approach This study was carried out through field measurement and computational fluid dynamics methods. The parameters of the study are void types and sizes, and a wind angle was used to formulate case studies. Findings The results indicate that the provision of a single-sided horizontal void larger by 50% increase the indoor air velocity performance up to 322.37% to 0.471 m/s in the living unit and achieves the required velocity for thermal comfort. Originality/value Passive design features are the most desirable techniques to enhance natural ventilation performance in the high-rise residential apartments for thermal comfort and indoor air quality purposes.

Thermal comfort practices for precast concrete building construction projects: towards BIM and IOT integration

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zul-Atfi Bin Ismail
Keyword(s):  
Thermal Comfort ◽  
Construction Projects ◽  
Natural Ventilation ◽  
Thermal Sensation ◽  
Precast Concrete ◽  
Building Energy ◽  
Building Construction ◽  
Building Projects ◽  
Content Type ◽  
Environmental Objectives

PurposeImproper evaluation and information mismanagement concerning thermal comfort appears to negatively affect occupants' satisfaction and building energy consumption in precast concrete (PC) building contexts. Predictive models are particularly problematic in PC building construction projects where natural ventilation levels do not coincide with occupants' thermal comfort and thermal sensation specifications.Design/methodology/approachA systematic literature review is undertaken to explore the viability and benefits of a new ICT-based approach for meeting social and environmental objectives.FindingsSophisticated thermal comfort system solutions are essential for optimising thermal comfort and saving energy in PC building construction projects.Originality/valueIt is imperative that designers and manufacturers are kept up-to-date with the possibilities and potentials associated with new and nascent technologies so that building projects can meet key sustainability criteria.

Determination of human thermal comfort due to moisture permeability of clothes

2018 ◽  
Vol 30 (4) ◽  
pp. 462-476 ◽  
Author(s):  
Krittiya Ongwuttiwat ◽  
Sudaporn Sudprasert ◽  
Thananchai Leephakpreeda
Keyword(s):  
Water Vapor ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Ambient Air ◽  
Coefficient Of Determination ◽  
Human Comfort ◽  
Content Type ◽  
Human Thermal Comfort ◽  
Moisture Permeability

Purpose The purpose of this paper is to present the determination of human thermal comfort with wearing clothes, with different water vapor permeability. Currently, the predicted mean vote (PMV) equation is widely used to determine thermal sensation scales of human comfort. However, moisture permeability of clothes has been not taken in account where the heat is lost from a human body due to water vapor diffusion through clothes. Design/methodology/approach In this study, the heat loss is derived based on the real structure of textiles, causing water vapor pressure difference between air on skin and ambient air. The PMV equation is modified to differentiate a thermal sensation scale of comfort although patterns of clothes are the same. Interview tests are investigated with wearing clothes from three types of textiles: knitted polyester, coated nylon–spandex, and polyurethane, under various air conditions. Findings The moisture permeabilities of knitted polyester, coated nylon–spandex and polyurethane are 16.57×10−9 kg/m2 s•kPa, 9.15×10−9 kg/m2•s•kPa and 2.99×10−9 kg/m2•s•kPa, respectively. The interviews reveal that most people wearing knitted-polyester clothes have the greatest cold sensations under various air conditions since moisture permeability is the highest, compared to coated nylon–spandex, and polyurethane leather. Correspondingly, the predicted results of the modified PMV equation are close to the actual mean votes of interviewees with a coefficient of determination R2=0.83. On the other hand, the coefficient of determination from the predicted results of the conventional PMV equation is significantly lower than unity, with R2=0.42. Practical implications In practice, this quantitative determination on human thermal comfort gives some concrete recommendations on textile selection of clothes for acceptable satisfaction of thermal comfort under various surrounding conditions of usage. Originality/value The modified PMV equation effectively determines human comfort on a thermal sensation scale due to the moisture permeability of clothes. To make generic conclusion, experimental results of additional three textiles, such as plain weave/lining polyester, knitted spandex, and open structure polyester, are reported. They confirm that the modified PMV equation effectively determines human comfort on a thermal sensation scale due to the moisture permeability of clothes.

scholarly journals Effect of Landscape Microclimates on Thermal Comfort and Physiological Wellbeing

2019 ◽  
Vol 11 (19) ◽  
pp. 5387 ◽  
Author(s):  
Binyi Liu ◽  
Zefeng Lian ◽  
Robert D. Brown
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Thermal Comfort ◽  
Skin Temperature ◽  
Skin Conductance ◽  
Thermal Sensation ◽  
Global Climate ◽  
Evidence Base ◽  
Climate Conditions ◽  
Human Thermal Comfort

Global climate change and intensifying heat islands have reduced human thermal comfort and health in urban outdoor environments. However, there has been little research that has focused on how microclimates affect human thermal comfort, both psychologically and physiologically. We investigated the effect of a range of landscape microclimates on human thermal comfort and health using questionnaires and physiological measurements, including skin temperature, skin conductance, and heart rate variability, and compared the results with the effect of prevailing climate conditions in open spaces. We observed that in landscape microclimates, thermal sensation votes significantly decreased from 1.18 ± 0.66 (warm–hot) to 0.23 ± 0.61 (neutral–slightly warm), and thermal comfort increased from 1.18 ± 0.66 (uncomfortable–neutral) to 0.23 ± 0.61 (neutral–comfortable). In the landscape microclimates, skin temperature and skin conductance decreased 0.3 ± 0.8 °C and 0.6 ± 1.0 μs, respectively, while in the control, these two parameters increased by 0.5 ± 0.9 °C and 0.2 ± 0.7 μs, respectively. Further, in landscape microclimates, subject heart rate variability increased significantly. These results suggest landscape microclimates improve human thermal comfort and health, both psychologically and physiologically. These findings can provide an evidence base that will assist urban planners in designing urban environments for the health and wellbeing of residents.

The effects of firefighting boots and personal protective equipment load on foot thermal comfort

2021 ◽  
pp. 004051752110265
Author(s):  
Miao Tian ◽  
Xianghui Zhang ◽  
Xumei Tang
Keyword(s):  
Thermal Comfort ◽  
Skin Temperature ◽  
Personal Protective Equipment ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Whole Body ◽  
Protective Equipment ◽  
Human Foot ◽  
Physiological Variables ◽  
Psychological Scales

Maintaining foot comfort is important as it influences the overall comfort of the human body. Shoe microclimate and foot skin temperature have been suggested to contribute to the thermal sensation of the foot. Considering the thermal environment and personal protective equipment (PPE) used for structural and proximity firefighting, climatic chamber tests with 13 male participants were conducted during standing and walking. Four test conditions – unloaded with training shoes, loaded with training shoes, unloaded with firefighting boots, and loaded with firefighting boots – were designed to investigate the effects of firefighting boots and PPE load on the thermal comfort of the human foot. Physiological variables of in-shoe and foot skin temperature at the whole and local regions of the foot were measured and subjective responses were gathered using psychological scales. The results showed that wearing firefighting boots may elevate the thermal sensation of wearers. The PPE load increased the in-shoe and foot skin temperature as well as subjective ratings. Subjective sensations of the foot were strongly correlated with in-shoe and skin temperature in the plantar regions. Correlation analysis of thermal sensation at the whole and local foot regions indicated that the sensation at the forefoot was closest to the whole foot, followed by the midfoot and heel. The findings address the relationship of physiological and subjective variables as well as the thermal sensation of whole and local foot regions, which can be considered for footwear design and thermal comfort prediction of the foot and whole body.

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