Comfort Studies Research Articles

Thermal comfort and gender affirmation: A virtual ethnography of extreme heat among trans women in Rio de Janeiro

The multisensory experience of feeling hot, breathless, sweaty, and weak during heat spells among transgender people is a critically understudied area in both medical anthropology and thermal comfort research. This article contributes to the anthropology of heat and humidity by intersecting with health and thermal comfort studies. Through virtual ethnography with three trans women in Rio de Janeiro in 2021 and 2022, the research reveals that trans women in the city face heightened risks of heat stress and thermal discomfort due to unsafe living conditions, side effects of gender-affirming modifications, and social discrimination. These findings highlight the urgent need to address the specific challenges transgender individuals face in accessing thermal safety and underscore the importance of considering their unique needs.

Comparative study of outdoor thermal comfort: Residents vs. tourists at Xi'an Ming Dynasty Ancient city wall scenic area

This study explores the thermal perceptions and comfort of residents and tourists at the Xi'an Ming Dynasty Ancient City Wall Scenic Area, addressing a gap in comparative outdoor thermal comfort studies in historical settings. Meteorological measurements and questionnaires collected between July 2019 and March 2021 analyze physical, individual, social, and psychological factors influencing thermal sensation, comfort, and acceptability across seasons. The RayMan model calculates Physiological Equivalent Temperature (PET), with data analyzed using SPSS 27.0. Results show Neutral PET (NPET) values of 17.1 °C for residents and 18.6 °C for tourists, and Preferred PET (PPET) values of 18.4 °C and 20.8 °C, respectively. Thermal Acceptability Ranges (TAR) are 13.5 °C–26.7 °C for residents and 15 °C–24.1 °C for tourists. Whether the measurement space contains water sources significantly affects temperature and humidity, while vegetation impacts wind speed. Physical factors predominantly affect perceptions, with individual factors becoming more important for tourists in winter. The findings provide insights for optimizing the thermal environment in scenic open spaces to enhance the comfort of both residents and tourists.

Local versus general anesthesia for stapes surgery: a prospective study of comfort and results on 100 ears.

To demonstrate the non-inferiority of perioperative comfort in patients undergoing otosclerosis surgery under local anesthesia versus general anesthesia and to compare audiometric results, quality of life and complications. A prospective non-interventional study was performed. Patients undergoing otosclerosis surgery between January 2019 and March 2021 at the University Hospital of Rennes were included consecutively. Perioperative comfort of LA versus GA (at ward admission, surgery, recovery and 48h following surgery) was measured on a visual analogue scale at 10 days postoperatively and quality of life by the Glasgow Benefit Inventory at 3 months. Complications and audiometric results were also assessed. To demonstrate the non-inferiority of LA versus GA with a margin of 1.5 points on the comfort VAS, a power of 80% and a first-order risk of 5, 100 patients were included and statistical analyses were performed in accordance with CONSORT2010 statement. One hundred ears were analyzed, 46% operated under local anesthesia and 54% under general anesthesia. The two groups were similar in terms of demographic and pathological characteristics. Local anesthesia was non-inferior to general anesthesia in terms of comfort with a comfort VAS of 8.74 ± 1.55 and 9.08 ± 0.93 respectively (p < 0.0001). There were no significant differences in rates of complications, audiometric results and quality of life between local and general anesthesia. Local anesthesia is non-inferior to general anesthesia in terms of perioperative patient comfort with similar audiometric results, postoperative quality of life and complication rates.

Investigation of thermal comfort and preferred temperatures among rural elderly in Weihai, China: Considering metabolic rate effects

As the population ages, the thermal environment indoors for the elderly has garnered extensive attention. However, current research on thermal comfort for the elderly is not comprehensive, particularly for rural elderly individuals who experience unique thermal perceptions and adaptation behaviors due to physical changes. Moreover, metabolic rates, which are often overlooked in thermal comfort studies for the elderly, play a crucial role. A year-long survey of thermal comfort was conducted in the rural areas of Weihai, a coastal city in China's cold region, collecting 203 questionnaires. Three different values of metabolic rates (recommended values, estimated values, and values calculated using Basal Metabolic Rate and Physical Activity Ratio) were analyzed. The results demonstrate that the Basal Metabolic Rate and Physical Activity Ratio method provides predictions of thermal sensation that more closely align with actual thermal sensations. The adaptive coefficient of the aPMV model was found to be −0.38 in colder environments and 0.272 in warmer ones. Additionally, using PMV regression, TSV regression, and Griffiths' method, we calculated the local elderly's comfort temperatures to be 18.9 °C (15.43–22.57 °C), 19.3 °C (15.16–22.75 °C), and 21.63 °C (21.34–23.49 °C) respectively. This study introduces a straightforward method for calculating metabolic rates in elderly individuals, offering new insights for research on thermal comfort in the elderly and expanding the database for thermal comfort studies. It lays a foundation for future design and standardization of housing for rural elderly populations.

Approach on enhancing the air conditioning system to improve the winter thermal environment in Eastern China Region's airport terminals

Passengers typically spend much time in commercial zones of terminals for retail, meals, and other services. Enhancing the study of thermal comfort in this local space is necessary. The climate in the Eastern China Region is variable and complex, making it more challenging to maintain the indoor thermal environment. This study conducted field measurements in winter in a commercial zone of one terminal to assess the thermal environment. Numerical simulations and PMV-PPD analyses were performed using the Computational Fluid Dynamics (CFD) program The results showed that the overall humidity in the commercial zone was low. There were notable differences in the temperatures and velocities of supply air among different air vents on the commercial island. Based on these initial conditions obtained by measurements, the simulations showed that localized areas under the breathing plane are either too hot (24°C and above) or too cold (18°C and below). The dissatisfaction percentage of the population exceeds 27%. This paper proposed that through enhancements in the air vent dimensions, layout, and air supply conditions, the temperature can be maintained in the range of 20-24°C. Furthermore, the PMV could be controlled within the range of -0.5 to 0.5. PPD was below 10%, reflecting compliance with Class I heating standards. Overall, findings from this study provide a less costly modification for thermal comfort improvement in commercial zones, and serve as a reference for the design and operation of air-conditioning systems to ensure thermal comfort in airport terminals’ commercial zones.

Thermal insulation provided by chairs with various clothing ensembles

The thermal insulation provided by chairs significantly influences human thermal comfort. On the one hand, it modifies the heat exchange mechanism at the contact points between the body and the chair surface. On the other hand, an increase in local thermal insulation can exacerbate differences in thermal insulation across various areas of the body, impacting overall comfort. However, the thermal insulation data for chairs are decades old and thus need to be updated to reflect modern designs and materials. Six typical office chairs were tested using a thermal manikin dressed in five typical clothing ensembles (ranging from summer to winter). The effective thermal insulation of the chairs varied between 0.04 and 0.14 clo when tested in the nude. The added values ranged from 0.04 to 0.30 clo when tested with different clothing ensembles. Higher clothing levels correspond to higher added chair thermal insulation. Therefore, a simple weighing method was developed to adjust the seasonal coefficient of the mean chair insulation value (0.75 in summer, 1.0 in transition, and 1.25 in winter). Furthermore, a simple model was established for calculating the overall clothing level for a seated person. The model was validated using data measured in this experiment and other external sources, with a minimum prediction mean error of 1.4 %. This study provides a reference for accurately acquiring the thermal insulation value of chairs for a seated person in thermal comfort studies.

Мой идеальный университет: физические и нефизические категории среды в представлениях студентов

&lt;p&gt;The article addresses the issue of identifying the needs of modern students in relation to the university educational environment. The study involved 48 architecture students aged 18 to 27 years (M=19.81; Mo=19; SD=1.82), including 83.33% girls (n=40) and 16.67% boys (n=8). The aim was to identify the most significant categories of the university educational environment. The research, which utilized a projective method &amp;ndash; an essay titled "My Ideal University" &amp;ndash; and content analysis of the responses, revealed that students consider non-physical categories to be the most important for effective and comfortable study. These categories include the organization of the educational process, the quality of the teaching staff, the curriculum, and opportunities for personal development. To confirm these results, a chi-square test was conducted, showing that non-physical categories of the educational environment were significantly more important than physical ones (&amp;chi;2=14.812, df=1, p=0.001). The most prominent physical environment categories mentioned by students included the equipment of offices and classrooms, the aesthetic qualities of the space, well-organized university grounds, coworking spaces, and rest areas in the interior. The data obtained can provide practical recommendations for designing new campuses or renovating and reconstructing existing universities. Precisely determining the optimal conditions for an effective and comfortable educational process will help avoid excessive financial investments in improving the physical environment.&lt;/p&gt;

Effect of a comfort scale compared with a pain numerical rate scale on opioids consumption in postanaesthesia care unit: the COMFORT study

BackgroundThe way that pain is assessed in the PACU could impact on postoperative pain and analgesic consumption. However, there is currently no evidence to support this speculation. The authors hypothesised that using a comfort scale reduces postoperative opioid consumption when compared with a standard numerical rating scale (NRS) to evaluate pain in the PACU. MethodsIn this cluster-randomised trial, patients were assessed using either a comfort scale (comfort group) or a pain NRS (NRS group). The primary outcome was the opioid consumption in the PACU. The main secondary outcomes were postoperative pain, nausea and vomiting, length of stay in the PACU, and satisfaction. ResultsOf 885 randomised patients, 860 were included in the analysis. Opioid consumption in the PACU was comparable in the comfort and NRS groups (median [interquartile range [IQR] 0 (0–5) vs 0 (0–6); P=0.2436), irrespective of the type of surgical procedure. The majority of patients did not need any postoperative opioid (59% in the comfort group and 56% in the NRS group, P=0.2260). There was no difference in postoperative pain, nausea and vomiting, time to reach an Aldrete score ≥9 after extubation, and global satisfaction. ConclusionsUsing a comfort scale to assess pain in the PACU did not spare any opioid compared with use of a standard NRS. Further studies focusing on patients at risk of increased postoperative opioid consumption are necessary. Clinical trial registrationNCT05234216.

Design of a Multicenter, Randomized Controlled Trial for the Treatment of Peripheral Neuropathic Pain (COMFORT Study) with a Micro-Implantable Pulse Generator.

Peripheral Nerve Stimulation (PNS) is an established therapy for chronic neuropathic pain of peripheral origin, typically following nerve injury. However, there is a paucity of Randomized Controlled Trials (RCTs) demonstrating the therapeutic benefits of PNS. The goals of the current study (COMFORT Study) are to document the safety and efficacy of the Nalu Neurostimulation in a PNS RCT, compared to conventional medical management (CMM). This is a prospective, multicenter, RCT evaluating the treatment of neuropathic pain with PNS therapy. One of the following four regions will be targeted for treatment: low back, shoulder, knee or foot/ankle. Consented subjects will undergo a baseline evaluation, after which they are randomized 2:1 (PNS+CMM arm to CMM arm). Subjects randomized to PNS+CMM arm will undergo a trial implant period using best clinical practices. Subjects who pass the trial phase, by showing a ≥ 50% reduction in pain relative to baseline, will receive the permanent implant. All subjects receiving a permanent implant will be followed for a total of 36 months. At the 3-month primary end point, subjects in CMM arm will be given the option to crossover into PNS+CMM arm, beginning with a trial implant. The study duration is expected to be 5.5 years from first enrollment to last follow-up of last subject and subsequent study closure. Adverse events will be captured throughout the study. The COMFORT study, described here, has the potential to demonstrate the efficacy and safety of the Nalu Neurostimulation System in the treatment of peripheral neuropathy. Results of this study will be the first Level-I evidence, out to 36 months, validating the use of this PNS system in the treatment of chronic pain. This study is designed to enroll the largest cohort, to date, of subjects comparing PNS+CMM vs CMM alone.

Crowdsourced data as a strategic approach to include the human dimension in outdoor environmental quality assessments

Outdoor environments extend living spaces as venues for various activities. Comfortable open public spaces can positively impact citizens' health and well-being, thereby improving the livability and resilience of cities. Considering the visitors' perception of these environments in comfort studies is crucial for ensuring their well-being and promoting the use of these spaces. However, traditional survey methods may be time- and resource-consuming to gather significant sample sizes, usually focusing on selected homogeneous samples. Crowdsourced data, then, has emerged as an alternative for assessing human perception, as it eases the collection of subjective feedback and potentially amplifies impact and inclusivity. This study presents a strategic approach for analyzing publicly available and willingly reported crowdsourced data from a digital mapping platform in outdoor comfort evaluations, aiming to verify whether these data are informative regarding environmental quality perception and to identify the environmental factors that people are most sensitive to. Urban parks located in New York City served as a case study. A multi-source, interdisciplinary information framework combined crowdsourced reviews with environmental data used to determine prevailing thermal conditions. Overall perception of parks was well-rated, revealing that their attractions and activities are probably the most appealing characteristics for park attendance. Regarding environmental perception, acoustic and thermal factors are clearly the most influential. Acoustics were well-rated, while the main aspect regarding the thermal domain is the recognition of shading as a mitigator for hot conditions. Environmental data provided complementary insights, particularly concerning the range of thermal sensations experienced in urban parks. The findings confirm that willingly reported crowdsourced data can provide valuable insights into urban crowd environmental perception, presenting a potentially suitable and effective method to include the human perspective in environmental quality assessments, as well as to evaluate and predict environmental-related risks.

Study of indoor local thermal comfort for impinging jet ventilation combined with ductless personalized ventilation under different cooling loads

Excessive temperature stratification and draught are two prominent drawbacks for impinging jet ventilation (IJV). Using IJV together with ductless personalized ventilation (DPV) (i.e., IJV + DPV) has been proved to be an effective way to reduce temperature stratification, but the draught rate around occupant would be increased. In the current work, an in-depth study on the characteristics of indoor local thermal comfort for IJV + DPV operating with different scenarios is done. Predictive models for the local thermal comfort indicators are developed to optimize the operating parameters (including supply velocity of IJV (Vs) and intake airflow rate of DPV (Df)) with different room cooling loads (Q). The results show that the application of IJV can be extended to spaces with high cooling loads (e.g., larger than 60 W/m2) by using together with DPV, but the risk of thermal discomfort increases. To avoid local thermal discomfort, the combination relationship between Vs and Df should be properly matched and this relation becomes more stricter with the increase of Q. It also obtains that the maximum cooling load that IJV + DPV can eliminate is less than 170 W/m2. At last, to ensure the IJV + DPV create a good local thermal comfort environment, design chart about the feasible ranges of Vs and Df are established for different values of Q. On the whole, the current study not only can provide a basis for the application of IJV + DPV in spaces with high cooling load, but also can provide theoretical guidance for the operation control and optimization design of the IJV + DPV.

Transient road signals simulation strategy in a Stewart platform

In this article, a transient road signals simulation strategy in a Stewart platform is presented. Real world road signals are transient signals and thus the accurate simulation of its frequency, amplitude and damping components is key for further simulation of comfort. This simulation strategy combines a kinematic model and a transient signal reconstruction strategy using an autoregressive method. First, the developed experimental kinematic model on a Stewart platform is presented. Then, the procedure to simulate real-world transient road signals in the driving simulator is explained. Finally, the developed strategy has been validated under real road signals combined in the 6 degrees-of-freedom to prove the accuracy between the real world experimental measured signal and the simulated signal in the hexapod. The final goal of the presented transient road signals simulation strategy is to perform further vehicle dynamics and ride and comfort studies in the simulation phase using electric Stewart platforms.

Progress and Future Prospects of Habitat Thermal Comfort Research

This paper is a comprehensive study in the topic of human environment and thermal comfort. Firstly, it introduces the concept of thermal comfort and its key role in human environments, and describes the influence of different factors on thermal comfort; secondly, it discusses the commonly used methods of thermal comfort assessment and the assessment indexes in different hot and humid environments; furthermore, it discusses the technologies and strategies to improve thermal comfort, such as the design of ventilation and air-conditioning systems as well as the green building materials, and so on. This paper intends to give a complete literature review for the study of human environment and thermal comfort, and to provide references and recommendations for future research and practice in related domains.

Study of thermal comfort in some standard school buildings: A case of Madagascar island

Study of thermal comfort in some standard school buildings: A case of Madagascar island

WRF-Comfort: simulating microscale variability in outdoor heat stress at the city scale with a mesoscale model

Abstract. Urban overheating and its ongoing exacerbation due to global warming and urban development lead to increased exposure to urban heat and increased thermal discomfort and heat stress. To quantify thermal stress, specific indices have been proposed that depend on air temperature, mean radiant temperature (MRT), wind speed, and relative humidity. While temperature and humidity vary on scales of hundreds of meters, MRT and wind speed are strongly affected by individual buildings and trees and vary on the meter scale. Therefore, most numerical thermal comfort studies apply microscale models to limited spatial domains (commonly representing urban neighborhoods with building blocks) with resolutions on the order of 1 m and a few hours of simulation. This prevents the analysis of the impact of city-scale adaptation and/or mitigation strategies on thermal stress and comfort. To solve this problem, we develop a methodology to estimate thermal stress indicators and their subgrid variability in mesoscale models – here applied to the multilayer urban canopy parameterization BEP-BEM within the Weather Research and Forecasting (WRF) model. The new scheme (consisting of three main steps) can readily assess intra-neighborhood-scale heat stress distributions across whole cities and for timescales of minutes to years. The first key component of the approach is the estimation of MRT in several locations within streets for different street orientations. Second, mean wind speed and its subgrid variability are downscaled as a function of the local urban morphology based on relations derived from a set of microscale LES and RANS simulations across a wide range of realistic and idealized urban morphologies. Lastly, we compute the distributions of two thermal stress indices for each grid square, combining all the subgrid values of MRT, wind speed, air temperature, and absolute humidity. From these distributions, we quantify the high and low tails of the heat stress distribution in each grid square across the city, representing the thermal diversity experienced in street canyons. In this contribution, we present the core methodology as well as simulation results for Madrid (Spain), which illustrate strong differences between heat stress indices and common heat metrics like air or surface temperature both across the city and over the diurnal cycle.

Machine Learning for Pedestrian-Level Wind Comfort Analysis

(1) Background: Artificial intelligence (AI) and machine learning (ML) techniques are being more widely employed in the field of wind engineering. Nevertheless, there is a scarcity of research on the comfort of pedestrians in terms of wind conditions with respect to building design, particularly in historic sites. (2) Objectives: This research aims to evaluate ML- and computational fluid dynamics (CFD)-based pedestrian wind comfort (PWC) analysis outputs using a novel method that relies on the sophisticated handling of image data. The goal is to propose a novel assessment method to enhance the efficiency of AI models over different urban scenarios. (3) Methodology: The stages include the analysis of climate data, CFD analysis with OpenFOAM, ML analysis using Autodesk Forma, and comparisons of the CFD and ML results using a novel image similarity assessment method based on the SSIM, MSE, and PSNR metrics. (4) Conclusions: This study effectively demonstrates the considerable potential of utilizing ML as a supplementary tool for evaluating PWC. It maintains a high degree of accuracy and precision, allowing for rapid and effective assessments. The methodology for precise comparison of two visual outputs in the absence of numerical data allows for more objective and pertinent comparisons, as it eliminates any potential distortions. (5) Recommendations: Additional research can explore the integration of ML models with climate data and different case studies, thus expanding the scope of wind comfort studies.

Investigating the impact of a large river and its surrounding contextual conditions on pedestrians’ summer thermal perceptions in a Cfa-climate city

Thermal comfort studies are usually employed to find subjective thermal responses [indicated by neutral temperature (NT), i.e. the temperature with no thermal stress] of residents from a region towards thermal environments. According to the recently published works in the literature, NTs are affected by many factors, such as geographical location and microenvironments. To elucidate the origins of these effects, the impact of microenvironment elements around a water surface on pedestrians’ thermal perceptions was systematically investigated in this work. The Fujiang River (FJR) in Mianyang City was taken as the sample site. The municipal meteorology station is located next to the site by around 2.5 km. By performing meteorology measurements combining questionnaires, it was found that the riverside NT (indicated by physiologically equivalent temperature, PET) of Mianyang in the summer of 2023 was 21.4 °C. The relationship between the distance from the water (DFW) and NT was quadratic linear. The same phenomenon took place by using either PET or Universal Thermal Climate Index (UTCI) indexes. Meanwhile, the meteorological contexts also affected NTs, including relative humidity (RH) and air velocity (Va). Regarding RH, the NPET increased from 15.2 °C (RH = 50%) to 26.9 °C (RH = 90%). In contrast, the NPET dropped from 23.0 to − 50.6 °C when the Va increased from 0.2 to 2.5 m/s, respectively. From our analysis, it was demonstrated that human thermal responses are significantly affected by both the microenvironmental and meteorological backgrounds around the water surface. Our work provides valuable insights for the proper use of water surfaces in urban design for adjusting thermal comfort.

A Systematic Review of Outdoor Thermal Comfort Studies for the Urban (Re)Design of City Squares

In the upcoming period, city squares’ urban redesign will be crucial in achieving sustainable development goals. This study presents a systematic review of OTC-related studies for the urban design of city squares using the PRISMA 2020 methodology. A review included a total of 173 papers from 2001 to 2023. The results identified five study types—clusters based on four pre-defined criteria: study approach, data collection methods, time duration, and primary objectives. The clusters indicate that more than half of all studies are related to the comparison of thermal comfort and heat mitigation measures. Most of the case studies were located in one of three climate zones: temperate oceanic (Cfb) (58 studies), hot summer Mediterranean (Csa) (40 studies), or humid subtropical (Cfa) (28 studies). The most common geometry of the analyzed urban square is medium-sized, is rectangular, and has dominant axel orientation south–north. Also, based on all five clusters, several research gaps were identified, appropriate for future research: the majority of studies related to the traditionally considered climate areas, no typology of urban square geometry configuration based on OTC assessment, and the lack of a local design model for assessing and improving the thermal comfort of city squares.

Numerical study of thermal comfort and energy efficiency about electrically heated footwear under a cold environment

PurposeThe paper aims to reveal the relationship among energy efficiency, thermal comfort and thermal regulation of electrically heated footwear and to investigate influencing factors on the energy efficiency and thermal comfort.Design/methodology/approachA finite volume model was proposed to simulate the two-dimensional heat transfer in electrically heated footwear (EHF) under an extremely cold condition. The model domain consists of three-layer footwear materials, a heating pad, a sock material, an air gap and skin tissues. Model predictions were verified by experimental data from cold-contact exposure. Then the influencing factors on the energy efficiency and thermal comfort were investigated through parametric analysis.FindingsThe paper demonstrated that the skin temperature control (STC) mode provided superior thermal comfort compared to the heating pad temperature control (HPTC) mode. However, the energy efficiency for the HPTC mode with a heating temperature of 38 °C was 18% higher than the STC mode. The energy efficiency of EHF while reaching the state of thermal comfort was strongly determined by the arrangement and connection of heating elements, heating temperature, thickness and thermal conductivity of footwear materials.Originality/valueThe findings obtained in this paper can be used to engineer the EHF that provides optimal thermal comfort and energy efficiency in cold environments.

Thermal Comfort Assessment of UPM Engineering Library in Tropical Climate Conditions

Thermal comfort is the study of indoor comfort level feel by the occupant in a room. This paper presents the study of thermal comfort that had been carried out in the library of engineering faculty at Universiti Putra Malayia in Serdang, Malaysia. The study was made in 4 days from 9 am to 11 am on October and November. This study was carried out to assess their thermal conditions during the occupants’ study hours. Thermal comfort variables were measured during study hours too. Qualitative and Quantitative data analysis showed that engineering library meet the requirement of comfort zone thermal conditions of ASHRAE standard 55 and ISO 7730. The result shows the environmental condition of the library is neutral to slightly warm in 4-point ASHRAE scale. The linear regression between Predicted Mean Vote and Operative Temperature reveals that the maximum acceptable temperature in this field of study is 26.5ºC.