Comfort Expectations Research Articles

User Expectations for Comfort, Discomfort, and Wearability of Wrist-Worn Devices

User Expectations for Comfort, Discomfort, and Wearability of Wrist-Worn Devices

Natural Radiation Sourced Heat Stress: Thermal Comfort Depending On Color Factor In Safety Reflector Vests

Research has shown that personal protective clothing is not used by employees due to personal reasons such as lack of working comfort and heat stress. Solar (UV) radiation creates a heat effect on people working outdoors. Agricultural and construction workers are exposed to solar radiation and are known to be at high risk of heat stress, especially in arid climates. It is important for the person to individually evaluate the ambient temperature as hot or cold for the ergonomic conditions of the employee. In this study, for increasing safety and comfort expectations, heat changes in reflector vests based on colors of heating due to natural radiation were estimated with thermal camera measurements, and gained heat values ​​of vests with different fabric thicknesses were estimated using fuzzy logic modeling over time, and the effects of natural radiation on human health were examined.

Understanding thermal comfort expectations in older adults: The role of long-term thermal history

Understanding how long-term thermal history affects thermal comfort expectations in older adults (65+) has implications for designing energy-efficient spaces in a changing climate. A growing number of studies focus on thermal sensation/preference votes to represent the current thermal comfort expectations, often overlooking their limitations. This study, however, investigates how factors shaping long-term thermal history link to the current 65+ adults indoor thermal comfort expectations during exposure to heat, by focusing on the upper limit of thermally acceptable temperature range, represented by a self-reported temperature threshold at which 65+ adults believe to feel uncomfortable by indoor heat (Tit). To find Tit, we use answers to “Above what temperature do you start feeling too hot indoors?” by survey respondents in Warsaw (n = 678) and Madrid (n = 527), who lived in their apartment ≥5 years. Statistically, we find indoor factors affecting long-term thermal experiences more significant in explaining 65+ Tit, when compared to outdoor factors such as distance to water, vegetation, or surface thermal radiance. Better-insulated buildings were associated with a lower Tit (p < 0.05), suggesting a higher thermal sensitivity of such building residents to heat. Our key findings indicate for normal housing units’ area (∼80 m2), personal factors such as Basal Metabolic Rate (main effect 95% CI = +0.42 – +2.6 °C) and health status (+0.11 – +1.68 °C) were associated with a higher 65+ Tit and lower thermal sensitivities to heat (p < 0.05). Findings shed light on the complexity of factors shaping indoor thermal comfort expectations among 65+ adults.

Problems and design strategies for elderly housing

In article describes the choice of methods for caring for the elderly and the comfort of living spaces are closely linked to aging-friendly design. Aging leads to a decline in physical functions, resulting in numerous obstacles in life. Therefore, the article analyzes the activity of housing for the elderly, taking aging-friendly design as a starting point. The development status of elderly housing needs in management, safety, social interaction, respect, and other aspects are examined. Design strategies conducive to aging, in terms of lighting, ventilation, detailed environment, public spaces, and intellectual services, are proposed. This aims to enhance comfort, safety, and livability in housing for the elderly and ensure the quality of life for older people. With the rapid growth in demand for elderly care, the vacancy rate in elderly housing reaches 50%. Due to changes in social and family structure, most elderly people live alone and lack security. Elderly homes have become ideal places for them. Currently, most care facilities lack professional management, and the services provided are too uniform. This leads to a weak sense of identity, with resources remaining underutilized. For semi-disabled individuals, standardized conditions do not always meet their expectations for rehabilitation care, medical services, and spiritual comfort. Elderly people face behavioral disorders affecting sight, hearing, smell, taste, and touch. Declines in the five senses, including speech impairments, mobility difficulties, and physiological disorders, lead to psychological needs such as socialization and self-realization. Aging-friendly design is based on the physiological and psychological cognitive characteristics of elderly people. It aims to create an environment that meets their needs and ensures effective care for them. The aim of the study is to analyze the problems associated with designing buildings for the elderly and to determine strategies for creating a supportive design that considers the needs and characteristics of the target audience. The work is aimed at improving the comfort, safety, and quality of life of elderly people by providing them with an appropriate living environment.

Accessories in clear aligner therapy: Laypeople's expectations for comfort and satisfaction.

This study explored the layperson's perception of comfort, satisfaction, and willingness to use various accessories in clear aligner therapy. A total of 267 people analyzed standardized intraoral photographs of a female model in orthodontic treatment using: 1) only clear aligner (CA), the control group; 2) clear aligner+attachments (AT); 3) clear aligners+Cl II elastics (EL); 4) clear aligner+hybrid treatment with esthetic braces (HEB); 5) Clear aligner+hybrid treatment with metallic braces (HMB); 6) clear aligner+mini-implants (MI); 7) clear aligner+mini-implants and elastics for intrusion (MIE). In addition, a social media questionnaire was distributed to assess the willingness to undergo orthodontic treatment with various accessories. There was a significant difference between CA and all the other groups (P<0.001), with CA being considered more comfortable and providing greater satisfaction compared to other accessories. Moreover, AT showed a significant difference in reducing treatment time compared to other groups. The CA was the most comfortable, exhibiting a higher satisfaction rate and a greater willingness to use it. The AT therapy was perceived as more comfortable and was associated with higher satisfaction and a greater likelihood of use, especially if it resulted in reduced treatment time. On the other hand, the participants reported that the HMB, MI, and MIE accessories were less comfortable.

Design optimization of an assisted living facility to improve summer thermal comfort in warming climates

Assisted living facilities with optimal summer thermal comfort are necessary to ensure improved quality of life for the older individuals in warming climates. Older individuals are exposed to higher mortality risks during periods of excessive heat. This study aims to identify and optimize key design variables for a passive house certified assisted living facility in Belgium with high comfort expectations using EnergyPlus to improve indoor thermal comfort during extreme climates. The sensitivity analysis used the Standard Regression Coefficient method with Latin Hypercube Sampling for eighteen design variables under four categories: layout, envelope, operation, and system. The analysis identified flat roof and external floor insulation as the most influential parameters, whereas lighting gain and cooling setback temperature were the least influential parameters. Furthermore, optimizing the reference building with the most sensitive design variables using a genetic algorithm based on the NSGA-II method found ideal configurations that would ensure minimum thermal discomfort hours during extreme summers. The study findings provide an evidence-based approach for building engineers and designers for early-stage design of assisted living facilities that maintain optimal comfort in mixed humid climates of Europe.

Deriving thermal sensitivity across educational stages: Evidence-based definition of Griffiths' coefficient

Thermal sensitivity directly impacts occupants' comfort by influencing neutral temperatures and comfort models. The Griffiths method, commonly used to derive thermal sensitivity, often assumes a constant value of 0.5°C-1 for calculating occupants' neutral temperatures. However, it is important to note that thermal sensitivity can vary depending on factors such as building type, climatic conditions, operation mode (i.e., natural ventilation, mechanical ventilation, or mixed mode), and occupants' age. This study aims to define whether age-dependent differences in thermal sensitivity exist in schools, achieved through the formulation of specific Griffiths coefficients for each educational stage. A field study was conducted in naturally ventilated classrooms within the same climate zone, collecting 1548 subjective responses and objective measurements from students across different educational stages. The results demonstrate that the thermal sensitivity in schools is lower than the commonly assumed values, especially in primary schools (0.085°C-1), and it increases with students' age. This variation is reflected in the corresponding neutral temperatures, which also increase with age. Using a constant Griffiths coefficient can lead to significant estimation errors in neutral temperature, potentially up to 1 °C, impacting both comfort and energy consumption. This study emphasizes that there are different thermal comfort expectations related to students’ age. To improve the reliability of adaptive thermal comfort models and ensure accurate neutral temperatures estimations, it is essential for future research to consider the students' age when evaluating the thermal sensitivity.

Exploring Information and Comfort Expectations Related to the Use of a Personal Ceiling Fan

Rising global temperatures have increased the need for research into human adaptability and comfort in buildings. To reduce comfort-related energy demands, low-energy-consumption alternatives for space cooling, such as personal environmental control systems (PECS), are being investigated. The implementation of PECS in office buildings is still underway, and little is known about how occupants’ expectations can influence their satisfaction with PECS and indoor environmental quality. This study examines the influence of tailored information and occupants’ comfort expectations on their thermal perceptions and satisfaction with a personal ceiling fan. Seventy-six participants completed an online questionnaire and attended a half-day session at 30 °C in a climate chamber in Germany. A manipulation technique to activate personal norms was used to test the influence of information on expectations. Results indicated higher reported thermal comfort in participants with more positive thermal expectations, regardless of their expectations of the building systems. These effects were largely moderated by personal norms, indicating the importance of activating normative motivations to increase thermal comfort. Occupants with negative expectations improved their perceptions of the fan when making personal adjustments to stay comfortable. However, this effect was not moderated by personal norms. Practical implications focus on manipulating occupants’ comfort expectations, e.g., by providing occupants with normative messages and individual control, to achieve greater comfort and acceptance of personal building controls in naturally ventilated buildings.

A case study: Analyzing the structure and optimizing the design of the aero handlebar assembly for the bicycle used in Japan's Olympic games

AbstractThis article examines a case study involving a 3D‐printed titanium “aero base handlebar” that failed and caused a crash during the Japan 2020 Olympics. The failure was attributed to the handlebar's design, which did not meet the increasing demands of customers in terms of safety, cost, reliability, and comfort. The handlebar was created using in‐house Altair product tools like Inspire Studio, SIMSOLID, and SULIS. Static structural analysis was conducted by estimating boundary forces. The analysis revealed that the original handlebar design, with a width of 50 mm, did not meet the required safety standards. To address safety concerns, the article proposed moving the arms forward by 35 mm (1.37 in.) to create clearance and attempting to secure a modified aero handlebar with an 85 mm width. The modified design incorporated a lattice structure, which exhibited higher levels of deformation and stresses, as well as lower maximum fatigue damage compared to the original 50 mm design. These results highlight the importance of considering customer expectations for safety, reliability, and comfort. Company Altair's advanced proprietary software, including Inspire Studio, SIMSOLID, and SULIS, in addition to employing lattice optimization methods, can support designers and engineers in fulfilling these requirements and creating products that are both safer and more reliable.

Framework to assess climate change impact on heating and cooling energy demands in building stock: A case study of Belgium in 2050 and 2100

Climate change has a broad impact on different aspects of energy use in buildings. This study explores potential changes in future heating and cooling energy demands. Increasing comfort expectations resulting from events like the extraordinary summer heatwaves in Europe are accelerating this trend to develop future scenarios for a better understanding of the relationship between future climate changes and the cooling need. This study used future weather data to estimate the heating and cooling energy demands in the Belgian building stock by 2050 and 2100 under base and business-as-usual scenarios using a dynamic building simulation model. The study showed that heating energy demand in the base scenario is expected to decrease by 8% to 13% in the 2050s and 13% to 22% in the 2090s compared to the 2010s. Additionally, the cooling energy demand is expected to increase by 39% to 65% in the 2050s and by 61% to 123% in the 2090s compared to the 2010s. Retrofit strategies applied to different building types contribute to lower the increase in cooling energy demand in the business-as-usual scenario compared to the base scenario. The cooling energy demand for an average building in the business-as-usual scenario is expected to increase with a range of 25% to 71% in the 2050s compared to 45% to 92% in the base scenario and 77% to 154% in the 2090s compared to 72% to 198% in the base scenario compared to the 2010s. The findings of the study provide insights to mitigate the impacts of climate change on heating and cooling energy demands.

Coupling PCM wallboard utilization with night Ventilation: Energy efficiency and overheating risk in office buildings under climate change impact

The rising population and increasing thermal comfort expectations are expected to exacerbate the already high HVAC use in offices, which unavoidably places a strain on energy supply systems. Storing thermal energy by incorporating phase change materials (PCMs) is an effective method for improving the buildings’ energy efficiency. Understanding how a PCM wallboard responds to climate change (CC) is crucial to maintaining its viability and effectiveness in achieving energy efficiency and sustainability goals during a building’s lifetime. This study presents a methodological framework to assess the performance of a building utilizing PCM wallboards in terms of cooling/heating energy demand (and corresponding GWP and operation cost) and occupant thermal comfort considering the changing climate. As a case study, a hypothetical office building located in a cold semi-arid climate with high diurnal fluctuations was selected, and the performance of offices orienting in different directions was evaluated when PCM wallboards with different melting ranges were utilized. PCM19 with a melting range close to heating set point reduced the heating demand by 5.0–7.4% for 2020 and 7.8–9.2% for 2050; while PCM25 with a melting range close to cooling set point yielded cooling reductions of 1.9–4.3% for 2020 and 0.7–2.4% 2050. However, PCM19 and PCM25 were ineffective in cooling and heating, respectively, as they were not compatible with the chosen set points. Coupling PCM25 with night-ventilation (NV) significantly enhanced the cooling savings (NV: 23.2–25.7% for 2020; 13.9–15.7% for 2050; NV + PCM25: 29.4–30.6% for 2020; 16.6–17.5% for 2050); though, the effectiveness of NV was impaired with rising night temperatures due to CC. Hourly energy analysis demonstrated varying performance of wallboards based on the time of day, suggesting potential benefits in supply–demand dynamics and time-of-use energy pricing. In naturally-ventilated scenarios, PCM utilization was ineffective in reducing indoor overheating risk, even when night-ventilation was introduced. Results highlight that to effectively mitigate indoor overheating risk in office buildings, PCM wallboards should be coupled with air-conditioning and night-ventilation. Furthermore, for a comprehensive evaluation of the energy/GWP/cost saving potential of a PCM wallboard during a building's lifetime, not only the current but also the projected local climate should be considered given the shifting energy demand towards cooling due to climate change. Overall, this study provides valuable insights into effective PCM wallboard utilization and lays the groundwork for enhancing the resilience of built environments in the face of climate change challenges.

Behavioral adaptations to cold environments: A comparative study of active nomadic and modern sedentary lifestyles

Modern occupants hardly use their capacity to adapt to the wide range of thermal environments due to living in well-insulated buildings with indoor climatization. However, climate change with associated health hazards necessitates exploring the limits of human adaptability to extreme environments. Thus, this work compared the adaptive actions of Tuvan nomads living in lightweight yurts in Siberia and modern sedentary dwellers from the Netherlands. The descriptive analysis focused on differences in behavior, thermal exposure, and comfort expectations. Body accelerometry, skin, and exposure temperature were monitored over 3 days in wintertime using wearable sensors, while the indoor environment was monitored using stationary sensors. A significant difference in the daytime lifestyle between the Dutch and the Tuvans was reflected in the time spent indoors (66–100% vs. 15–51%), frequency of going outdoors (1–6 vs. 6–25 times), and the indoor clothing fashion (<1 clo vs. 1.1–2.3 clo). The nomadic population was exposed to a greater variation of the thermal environment (from −30 °C to +40 °C) in contrast to the Dutch (from 21 to 26 °C). Skin temperatures and the estimated Predictive Mean Vote (PMV) index indicated that Tuvans were relatively warm indoors than the Dutch, despite cold outdoors (mean −22 °C). The combination of greater clothing insulation, greater overall daily activity, elevated metabolic rate, and occasional overheating indoors defined such a difference. Nomads mainly relied on their actions rather than housing to keep themselves warm, and they had modest expectations of comfort, making them accept wider temperature variations, which was the crucial difference from modern expectations.

Dynamic Thermal Performance Analysis of PCM Products Used for Energy Efficiency and Internal Climate Control in Buildings

PCMs are attractive for the future generation of buildings, where energy efficiency targets and thermal comfort expectations are increasingly prioritized. Experimental analysis of local thermal processes in these dynamic components and whole-building energy consumption predictions are essential for the proper implementation of PCMs in buildings. This paper discusses the experimental analysis of the thermophysical characteristics of both a latent heat storage material (PCM) and a product containing this PCM. The prototype product under investigation is a panelized PCM technology containing inorganic, salt-hydrate-based PCM. The thermal analysis includes studies of melting and freezing temperatures, enthalpy changes during phase change processes, nucleation intensity, sub-cooling effects, and PCM stability. The PCM’s stability is also investigated, as is the ability of PCM products to control local temperatures and peak load transmission times. Two inorganic PCM formulations based on calcium chloride hexahydrate (CaCl2.6H2O) were prepared and tested in laboratory conditions. Material-scale testing results were compared with outcomes from the system-scale analysis, using both laboratory test methods as well as field exposure in test huts. This work demonstrates that PCM technologies used in buildings can effectively control both the magnitude of thermal storage capacity as well as the time of the peak thermal load. It was found that commonly used material-scale testing methods may not always be beneficial in assessing the dynamic thermal performance characteristics of building technologies containing PCMs.

Thermal comfort and adaptive capacities: Differences among students at various school stages

In educational buildings, ensuring thermal comfort is crucial in guaranteeing pupils' health and high learning. Previous studies show different thermal comfort expectations in the educational stage. However, only a few studies have simultaneously investigated all educational stages and considered schools and universities in different areas. In this study, data collected from 24 classrooms in the winter and 1548 questionnaires were used to analyse all the educational stages in one region, thus minimising the possible bias associated with the climate zone, operation mode, and cultural adaptation. Hence, all differences in the perception of the thermal environment were likely to be due to only the educational stage. The results showed that adaptive capacities, such as clothing insulation and window operation, decrease at lower educational stages. Neutral, comfort and preferred temperatures are largely dependent on the educational stage and increase with it (e.g. 20.6, 21.7, 23.1, and 23.6 °C for primary school, middle school, high school, and university, respectively). Furthermore, a linear relationship between students’ age and neutral temperature was derived. These differences in thermal comfort expectations were reflected in the variable predictive capability of the predicted mean vote (the greatest difference between predicted and actual thermal sensations in primary school). Overall, this study provides evidence of the necessity for thermal comfort models that can capture variations depending on the educational stage.

Exploring expectations of Chinese patients for total knee arthroplasty: once the medicine is taken, the symptoms vanish

BackgroundPreoperative expectations of total knee arthroplasty (TKA) outcomes are important determinants of patient satisfaction. However, expectations of patients in different countries are affected by cultural background. The general goal of this study was to describe Chinese TKA patients’ expectations.MethodsPatients scheduled for TKA were recruited in a quantitative study(n = 198). The Hospital for Special Surgery Total Knee Replacement Expectations Survey Questionnaire was used for survey TKA patients’ expectations. Descriptive phenomenological design was used for the qualitative research. Semi-structured interviews were conducted with 15 TKA patients. Colaizzi’s method was used for interview data analysis.ResultsThe mean expectation score of Chinese TKA patients was 89.17 points. The 4 highest score items were walk short distance, remove the need for walker, relieve pain and make knee or leg straight. The 2 lowest score items were employed for monetary reimbursement and sexual activity. Five main themes and 12 sub-themes emerged from the interview data, including multiple factors raised expectations, expectations of physical comfort, expect various activities back to normal, hope for a long joint lifespan, and expect a better mood.ConclusionsChinese TKA patients reported a relatively high level of expectations, and differences across cultures result in different expectation points than other national populations, requiring adjustment of items when using assessment tools across cultures. Strategies for expectation management should be further developed.Level of evidenceLevel IV.

Cooling is hotting up in the UK

The cooling of buildings is currently responsible for about 20% of total electricity use worldwide. It is estimated that the electricity needed for cooling will more than triple by 2050. Despite this concerning outlook, little attention has been paid to cooling demand in policy and research in the United Kingdom (UK). The demand for space cooling in the UK’s domestic and non-domestic buildings is currently small—about 10% of total electricity use. However, this has the potential to increase as the climate warms and expectations of comfort grow. This paper reviews UK cooling demand and how this has been considered in energy policy. Following a thorough review of the existing literature using a cooling decarbonisation framework (Avoid, Improve and Shift), it is clear there is a limited understanding of the future UK cooling demand for domestic buildings in a warmer future as well as how policy makers and households should act. More importantly, this sector appears under-represented in the UK research and policy landscape compared to heating despite obvious technological crossovers associated with electrification. Several policy and research recommendations have been made based on these findings.

Examining the Difference Between Laboratory Measurements and Calculation Results in Impact Sound Insulation

Architectural structures are designed and built to provide a comfortable living space to their users due to their function. One of the most important comfort expectations in buildings is acoustic comfort. Since the impact sound insulation between floors, which is one of the sub-headings of acoustic comfort, is evaluated together with the floor covering, resolving the discomfort caused by incomplete or incorrect evaluations during the design phase can be both more difficult and more costly during operation. In practice, it has been observed that there are differences between the laboratory measurements made according to the EN ISO 10140-3 standard and the calculations made according to the EN ISO 12354-2 standard for impact sound insulation. This difference can lead to an uncomfortable living space as the targeted acoustic performance cannot be achieved. This situation creates the need for a calculation model that gives more realistic results during the design phase. In this study, the variables that cause the difference between laboratory measurements and calculation results in impact sound insulation will be examined and improvement suggestions will be developed for the calculation of impact sound insulation according to the EN ISO 12354-2 standard.

A Flywheel-Based Regenerative Braking System for Railway Vehicles

Abstract Regenerative braking is a technique that employs electric motors to convert the dynamic mechanical energy from the motor’s spinning rotor and any attached loads into electricity. However, such a type of regenerative braking can only slow but not stop the vehicle because there is too little energy to excite the motor acting as a generator at low speeds. Therefore, this paper presents a unique flywheel-based regenerative braking system for railway vehicles. This system is supposed to meet high safety and comfort expectations in all operating conditions. The braking action control of this system should allow braking of empty or loaded vehicles according to load, the anti-blockage braking action of wheels and prevent wheel-slide during braking or wheel slip during acceleration. The new regenerative braking system under development, like any kinetic energy recovery system, requires the application of continuously variable transmission. The essence of the new solution is to design and build this type of variable transmission using only one planetary gear controlled through the powertrain control module for an electric motor cooperating concurrently. This paper describes complete modelling and simulation realisation on a closed-loop servomotor drive, which cooperates with the variable transmission of the regenerative braking system based on the Scilab/Xcos environment.

Reverse subsidy dilemma caused by the transformation from individual heating to central heating

With the increase in household income enhancing people's expectations for life comfort, the demand for central heating in hot summer and cold winter areas (HSCWs) has increased. This study aims to explore whether it is appropriate to promote central heating in HSCWs from the perspectives of inequality and reverse subsidies. Reverse subsidy dilemma caused by the transformation from individual heating to central heating was proposed by the analysis relying on utility theory. This paper presents data suggesting that individual heating could provide more options for different household income groups than could central heating. Furthermore, the heating inequality among different income groups is assessed, and reverse subsidies from the poor to the rich are discussed. We find that the implementation of central heating leads to few adverse effects and high utility for the rich and increased expenditures and low utility satisfaction for the poor at the same price level.

Design &amp; development of a prototype of the layman’s air-cooler

This paper deals with the design &amp; development of a prototype of the layman’s air-cooler. In summer seasons, we require cold water and cooled air because of scorching temperature. Modern appliances fulfilling these requirements need high power and are costly. So, we propose modified simple air cooler, which is portable and is low maintenance machine. Air cooler is one of the major consumers of electrical energy in many parts of the world today. Air cooler causes energy shortage for example in China. The demand can be expected to increase because of changing working times increased comfort expectations and global warming. Air conditioners are pretty expensive themselves and adding to them their power bills makes it out of reach for most common man. So opting for an air cooler is probably one solution which not only is cheaper as an appliance, but also uses lower power than conventional air conditioners. The work presented here is the mini-project work of the second semester engineering students of electronics &amp; communication engineering department of Dayananda Sagar College of Engg., Bangalore, Karnataka