Clothing Thermal Insulation Research Articles

Prevalence of cold-related symptoms among Thai chicken meat industry workers: association with workplace temperature and thermal insulation of clothing.

This study determined the association of cold-related symptoms with workplace temperature and thermal insulation of clothing among Thai chicken industry workers. Three hundred workers were interviewed regarding cold-related symptoms, which were regressed on worksite temperature and protective clothing. In total, 80% of workers reported respiratory symptoms; 23%, cardiac symptoms; 62%, circulation disturbances; 42%, thirst; 56%, drying of the mouth; and 82%, degradation of their performance. When adjusted for personal characteristics, respiratory symptoms were 1.1‒2.2 times more prevalent at −22‒10°C than at 10‒23°C. At −22‒10°C, cardiac symptoms increased by 45%, chest pain by 91%, peripheral circulation disturbances by 25%, and drying of the mouth by 57%. Wearing protective clothing with at least 1.1 clo units was associated with marked reductions in symptom prevalence. Therefore, temperatures lower than 10°C increased prevalence of cold-related symptoms, which are largely preventable by appropriate clothing use.

Influence of Air Velocity on the Total Thermal Insulation of Different Types of Clothing

According to the standards describing research on the total and resultant thermal insulation, the requirements for the microclimate in which tests are performed must be recorded. However, these values are given with uncertainty. According to the EN ISO 15831 and EN 342 standards, air velocity should be set to (0.4 ± 0.1) m/s. For this reason, it is necessary to verify to what extent values exceeding the said range affect the results of the thermal insulation. Research was carried out for 3 sets of clothing differing in the number of layers of the material. The influence of air velocity on clothing thermal insulation was examined with three values of Va: 0.4 m/s, 0.8 m/s and 1.2 m/s. Correction factors (CFs) were calculated and compared with the CF values set out in the EN ISO 9920 standard.

Thermal sensation in outdoor urban spaces: a study in a Tropical Savannah climate, Brazil.

The present study carried out assessments regarding thermal sensations under different weather conditions in three urban areas in Cuiabá, Brazil, a Tropical Savannah climate (Aw) region. Thermal acceptability by means of thermal sensation votes (TSV) was addressed based on the estimation of the Universal Thermal Climate Index (UTCI) values. Important issues related to clothing thermal insulation (Icl), the effect of gender on thermal sensation, and implications of artificial conditioning (AC) systems are also evaluated. Micrometeorological variables were determined and 685 questionnaires were applied to evaluate individual pedestrian thermal preferences. The Icl observed in the Tropical climate was lower than that intrinsically inputted by the UTCI for Temperate climates. The local thermal comfort zone ranged between 21.5 and 28.5 °C, with both thresholds higher than those observed in studies conducted in Subtropical, Mediterranean, and Continental Temperate climates while the local hot thermal sensation categories were displaced at least 3 °C above than those for the aforementioned climates. The effect of gender on thermal sensation indicated that females are more sensitive to cold stress conditions than males, requiring higher Icl for temperatures below 28 °C. The physiological adaptation by continuous exposure to AC systems reduced the neutral temperature between AC and non-artificial conditioning system users (NAC) by 0.8 °C, with more intense differences in hot TSV ranges. This study reveals differences between stated TSV classes derived for other climates and those resulting from TSV declared by Savannah local residents, indicating that local thermal sensation scale for UTCI in an important key for environment planning.

Development of a Data-Driven Predictive Model of Clothing Thermal Insulation Estimation by Using Advanced Computational Approaches

Clothing condition was selected as a key human-subject-relevant parameter which is dynamically changed depending on the user’s preferences and also on climate conditions. While the environmental components are relatively easier to measure using sensor devices, clothing value (clo) is almost impossible to visually estimate because it varies across building occupants even though they share constant thermal conditions in the same room. Therefore, in this study we developed a data-driven model to estimate the clothing insulation value as a function of skin and clothing surface temperatures. We adopted a series of environmental chamber tests with 20 participants. A portion of the collected data was used as a training dataset to establish a data-driven model based on the use of advanced computational algorithms. To consider a practical application, in this study we minimized the number of sensing points for data collection while adopting a wearable device for the user’s convenience. The study results revealed that the developed predictive model generated an accuracy of 88.04%, and the accuracy became higher in the prediction of a high clo value than in that of a low value. In addition, the accuracy was affected by the user’s body mass index. Therefore, this research confirms that it is possible to develop a data-driven predictive model of a user’s clo value based on the use of his/her physiological and ambient environmental information, and an additional study with a larger dataset via using chamber experiments with additional test participants is required for better performance in terms of prediction accuracy.

Review of application of thermal manikin in evaluation on thermal and moisture comfort of clothing

The thermal manikin is a complicated, delicate, and expensive tool, which could simulate the heat exchange between environment and human body and measure the evaporative resistance and thermal insulation of clothing. This study reviewed the application of thermal manikin in evaluation on thermal and moisture comfort of clothing and the thermal manikin through three aspects namely traditional thermal manikin, thermal regulation manikins, and numerical thermal manikins. Several typical manikins (Newton, Coppelius, SAM, Walter, Ruth, and Wenda) were described, and the features, application fields, measurement principles, and research status of thermal manikin were demonstrated. Finally, the development trends of thermal manikin were proposed. Not only would this work promote the further development of the thermal manikins themselves and the innovation of relevant technologies but also provide valuable information for the development and design of relevant products.

Dressed for the season: Clothing and outdoor thermal comfort in the Mediterranean population

Outdoor comfort, as perceived by the average person, is linked to a wide variety of parameters. Microclimatic, physiological and psychological factors influence the perception of each individual and more generally, that of the local population, given the acclimatization phenomenon with respect to local climate. One of the few mechanisms available to protect ourselves from the outdoor climate to achieve thermal comfort is choosing adequate thermal insulation in our clothing. Each individual can easily implement this protection mechanism to adjust her/his own thermal sensation. In order to quantitatively evaluate the comfort provided by thermal insulation of clothing, the following parameters must be considered: (i) outdoor thermal conditions, such as air and mean radiant temperature, relative humidity and wind speed; (ii) the individuals' genders and ages; and (iii) their expressions of thermal comfort, with reference to the specific local climate to which each subject is usually exposed (acclimatization). This work aims at analyzing these factors, by means of an experimental investigation, with particular reference to a statistically relevant sample of the Mediterranean population. To this end, thermal comfort is expressed by means of the Mediterranean Outdoor Comfort Index (MOCI), which was specifically created to describe the thermal comfort of the Mediterranean population. Results allow defining the preferred clothing's thermal resistance “ICL,med” for Mediterranean people, evidencing the different preferences as a function of gender and age. A slight tendency towards higher thermally-insulated clothing has been assessed with increasing age of the interviewees and among female interviewees.

The laboratory investigation of the clothing microclimatic layers in accordance with the volume quantification and qualification

Some of the researches expressed connection between the numbers and size of the microclimatic air layers on thermal insulation of clothing. The insulation of the ensembles is much affected by the air enclosed between the clothing layers. In loose fitting clothing, they are less subjected to compression and thus add more to the overall thermal insulation. The heat and the moisture are released from the body into the microclimatic layers, subsequently changing properties of the entrapped air. The volume of the microclimatic air layers was investigated by the use of non-contact 3D CAD method. The temperature and humidity changes of microclimatic layers were also observed. This paper represents layer by layer quantification of the clothing ensemble volume with jackets as covering garment and the impact of the microclimatic volume on the clothing insulation. The three-level laboratory testing was performed with human subjects dressed in selected ensembles.

4788 Thermal Manikin Measurements of Protective Clothing Assemblies

The thermal comfort of a foundry worker is very important and related to many factors, i.e., the structure of the protective clothing assembly, the number of layers and their thickness, as well as the distance between the body and appropriate underwear. The research undertaken aimed at checking thermal insulation for assemblies consisting of aluminized protective clothing and appropriate underwear in two sizes and without underwear. Measurements of the clothing thermal insulation were conducted using a thermal manikin dressed in two-layer protective clothing and three kinds of underwear products covering the upper and lower parts of the manikin. The first part of the paper presents a comparison of results of thermal insulation measurement of two kinds of protective clothing: a traditional one made of aluminised glass fabrics and a new one made of aluminised basalt fabrics. Each of the protective clothing was worn on three kinds of underwear products in m and s sizes. The influence of the underwear size was noted. In the second part of paper, measurements were made for two aluminized basalt clothing variants: commercial and a prototype with modifications in static and dynamic conditions. The results were discussed.

Abuse of empire style robe to thermal insulation and body discomfort (part 2)

PurposeWomen in Western Europe wore empire style robes which were made with a light and thin fabric revealing their body. To stress the silhouette of their body, they applied oil to it or sprayed water on the robe so that it would cling to the body, and most women suffered from muslin disease, meaning flu and tuberculosis of the lungs in winter season. The purpose of this paper is to examine the thermal insulation of the robe with spencer jacket in dry and wet environment through thermal manikin experiments.Design/methodology/approachThree kinds of spencer jacket were made based on historical evidence and data, and experimental work for thermal insulation was conducted using a thermal manikin. The study measured the total thermal resistance of dress-jacket set: weight of the clothing before and after wetting, thermal insulation of the spencer jackets and set of clothing in dry and wet conditions, electric power consumption of the set of clothing in the wet condition and temperature inside the clothing and surface temperature of the wet set of clothing.FindingsThe thermal insulation of the robe with spencer jacket in the wet condition was in the range of 0.135-0.144 clo, which was about 80 percent lower than the range of values of 0.73-0.79 clo measured in the dry condition. This means that women felt uncomfortable in wetting condition or raining environment even when wearing the robe with a spencer jacket. Thermal insulation of clothing was dependent to the air gap under garment, clothing layers, ventilation through fabric and body part.Originality/valueIn this study, the thermal insulation of an empire style robe with spencer jacket in wet condition was measured using a dry thermal manikin, not with the sweating manikin. The authors measure the electric power consumption according to drying time of the clothing set at the body parts. In order to study the effect of different materials and clothing wetting, comparison experiments were conducted in dry and wet conditions using the rinse cycle of washing machine.

The issue of thermal comfort of medical clothing in the operating room

La ropa médica tiene la función principal de protección. Sin embargo, esta función debe estar correlacionada con una buena experiencia de comodidad para el usuario. La comodidad es un tema muy importante, ya que los profesionales están expuestos a situaciones de estrés que pueden influir, negativamente, en su desempeño laboral. Más específico, el confort térmico juega un papel crucial para el mejor rendimiento de la ropa médica usado en la sala de operaciones, que implica la regulación del calor y la transferencia de masa entre un cuerpo vestido y el medio ambiente, una vez que la ropa es la interfaz entre el cuerpo y el medio ambiente. El objetivo de este trabajo fue estudiar el comportamiento de propiedades térmicas de batas quirúrgicos y trajes de aire limpio usados en la sala de operaciones. Se realizó una comparación entre estos dos tipos de prendas con equipos Alambeta, para propiedades térmicas estacionarias y un Maniquí Térmico, para propriedades dinâmicas, como el flujo de calor y el aislamiento térmico. Se encontró que el aislamiento térmico de las prendas es estadísticamente diferente, mostrando que la diferencia entre los trajes puede ser percibida por el usuario.

Study of Multilayer Clothing Thermal Insulation Using Thermography and the Finite Volume Method

Study of Multilayer Clothing Thermal Insulation Using Thermography and the Finite Volume Method

Riscos para a saúde num ambiente térmico frio: o vestuário e uma onda de frio

Este trabalho apresenta um estudo de caso para ambiente térmico frio a céu aberto numa região de coordenadas geográficas 40.67ºN e 8.45ºW no lugar da Sernada do Vouga do concelho de Águeda e Distrito de Aveiro e foi realizado na primeira quinzena de fevereiro de 2015. Foi mantido o isolamento térmico do vestuário. Foram usados indicadores de sensação térmica e de isolamento térmico. Os resultados obtidos mostram que as sensações térmicas reais estão em concordância com as sensações térmicas previstas e que o isolamento térmico do vestuário deve ser adaptado para as condições termohigrométricas do ar húmido, de modo a evitar a falência do corpo.

Notes on the Calculation of the PMV Index by Means of Apps

In this work, all existing smartphone and web applications for the calculation of the PMV index running on different platforms for mobile devices have been compared with a reference software compliant with ISO 7730 Standard. Unfortunately, only four apps take into account all the six variables responsible for the thermal sensation (air temperature, mean radiant temperature, air velocity, relative humidity, metabolic rate and clothing thermal insulation) and in some cases data input appeared very hard (e.g. impossibility to consider decimal values). In addition, only one app seemed to take into account the correction of basic clothing insulation values due to pumping effect. Based on results from this preliminary test, we can conclude that web apps and smartphone tools for the evaluation of thermal comfort conditions by means of PMV presently on the market have to be used with special care (or, better, should not be used) especially by not skilled users could use them even for professional reasons.

Comparison of clothing thermal comfort properties measured on female and male sweating manikins

Thermal manikins simulating human body’s thermal regulatory system are essential tools for understanding the heat exchange between human body and the environment and also for evaluating the thermal comfort of clothing and near environment. However, most existing thermal manikins adopt a male’s body shape and no sweating female thermal manikin has been reported so far. Furthermore, it is unclear how body shape (viz. male vs female) affects the heat loss and perspiration from the body. We report on a novel female sweating thermal manikin “Wenda”. Thermal properties of the nude body and clothing ensembles measured on “Wenda” are compared with those measured on the male manikin “Walter”. It was found that, although the more curvaceous female body reduces the thermal insulation of the nude manikin, it increases the apparent evaporative resistance at the same time. This may be due to the fact that the more curvaceous female body increases the surface still air layer to add resistance to heat loss by conduction and evaporative water loss by diffusion, and significantly increases the percentage of effective radiative area and the resultant radiative heat loss per unit surface area. It was further shown that clothing thermal insulation and apparent evaporative resistance measured on Wenda are typically 0 ∼ 11% higher than those measured on the male sweating fabric manikin-Walter, probably due to the greater clothing microclimate volume on the female manikin resulting from the looser fitting of the garments on the smaller female body and the more curvaceous surface of the female body.

Comparative Analysis of the Thermal Insulation of Traditional and Newly Designed Protective Clothing for Foundry Workers.

An objective of the undertaken research was checking the applicability of aluminized basalt fabrics for the production of clothing for foundry workers. The results of flammability, the resistance to contact, convective and radiation heat, as well as the resistance to big molten metal splashes confirmed the thesis of applicability of the packages with the use of aluminized basalt fabric content for the assumed purpose; therefore, such protective clothing was produced. Thermal comfort of foundry workers is very important and related to many factors, i.e., the structure of the protective clothing package, the number of layers, their thickness, the distance between the body and appropriate underwear. In the paper, a comparison of the results of thermal insulation measurement of two kinds of protective clothing is presented: the traditional one made of aluminized glass fabrics and the new one made of aluminized basalt fabrics. Measurements of clothing thermal insulation were conducted using a thermal manikin dressed in the protective clothing and three kinds of underwear products covering the upper and lower part of the manikin.

Skin temperature and predicted discomfort of women wearing sheer Empire style dress

There are various thermal experiments for current clothing by human wear test but it is rare for historic clothing. A sheer dress fashion in winter time was told as one of the reasons which many women and the young died in the western history. Thus we studied the physiological responses to cold and thermal insulation of the empire style sheer dress by performing human wear test with three subjects. Empire style dresses are made of thin wool, sleek silk and transparent cotton and then human wear test begin in a cool climate chamber 18 °C(±1 °C) and 55 %(±5 %). We measured mean skin temperature, metabolic rate, thermal insulation of clothing, subjective thermal sensation and Predicted Mean Vote with the process which subjects sit down (30 min) and then exercise (30 min) and have a recovery (30 min). As the results we found mean skin temperature kept decreasing in rest period, increased in the middle of exercise period, and decreased again in recovery period due to sweating after exercise, thus the numerical values of skin temperature proved that women could not keep body temperature comfortable in winter. Also, PMV of women wearing empire style dress reached -2.0 within 30 min, and even -3.0 for the wetted skin and after chilling, and the predicted discomfort was calculated using the known equation: minimum 48.3 % at early recovery period through maximum 98.3 % at late recovery period, thus we confirmed thermal discomfort of women with both objective and subjective data together.

대학생의 신체부위별 추위지각 반응과 착의 행동

This study investigates gender differences in cold perceptions and wearing behaviors for cold adaptation. A questionnaire composed of items on cold perceptions, intentions toward wearing additional clothing, and clothing for outdoor environments, among others, was used. Each item in the survey targeted 260 male (MS) and female (FS) college students evaluated using a five-point Likert-type scale. Data were statistically analyzed using the independent sample t-test and correlations. Main results can be summarized as follows: MS subjects showed lower dependence on the thermal insulation of clothing because they felt less cold and had the better ability to cope with cold. MS subjects had higher dependence on underwear during cold seasons, and FS subjects tended to wear heavier clothing to compensate for their cold feet with insufficient insulation. In addition, it was preferable to estimate thermal effects of actual wear by taking into account gender differences in the physique. The study is limited in that the room temperature and the actual amount of clothing were not measured, which offers an avenue for future research.

Artificial Neural Network Estimation of Thermal Insulation Value of Children’s School Wear in Kuwait Classroom

Artificial neural network (ANN) was utilized to predict the thermal insulation values of children’s school wear in Kuwait. The input thermal insulation data of the different children’s school wear used in Kuwait classrooms were obtained from study using thermal manikins. The lowest mean squared error (MSE) value for the validation data was 1.5 × 10−5 using one hidden layer of six neurons and one output layer. The R2 values for the training, validation, and testing data were almost equal to 1. The values from ANN prediction were compared with McCullough’s equation and the standard tables’ methods. Results suggested that the ANN is able to give more accurate prediction of the clothing thermal insulation values than the regression equation and the standard tables methods. The effect of the different input variables on the thermal insulation value was examined using Garson algorithm and sensitivity analysis and it was found that the cloths weight, the body surface area nude (BSA0), and body surface area covered by one layer of clothing (BSAC1) have the highest effect on the thermal insulation value with about 29%, 27%, and 23%, respectively.

The effect of air gap on the total and local thermal insulation of Chinese male costumes from twenty minority ethnic groups

Clothing thermal insulation is an important thermo-physical parameter to determine thermal comfort. Previous studies have shown that clothing thermal insulation can be largely affected by the air speed, the body movement, the body posture, clothing physical properties and design features [1,2]. Air gaps trapped within the clothing microenvironment is one of the inherent factors that determine the thermal insulation of the clothing [3]. In this study, the effect of air gap on the total and local thermal insulation of 20 sets of Chinese male costumes was investigated by a 3D body scanner and thermal manikin measurements.

Impact of Clothing, Breathing and Body Posture on the Shaping of a Thermal Plume above a Human

The impact of clothing, breathing and body posture on the thermal plume above a thermal manikin was investigated. Measurements of air velocity and temperature above the manikin were performed at four different heights above a sitting and a lying manikin. The results obtained from tests above the sitting manikin show an inverse proportion between the thermal insulation of clothing and the air velocity in the thermal plume. Air velocity in the thermal plume with the breathing function switched on equalled 90–98% of the values obtained for non-breathing experiments. The use of the breathing function caused an asymmetry of the thermal plume above the manikin’s knees. The presence of an area of increased velocity and temperature originating from the breathing process was observed (“warm cloud”). Results obtained from the measurements above a lying manikin confirmed the impact of thermal insulation on the thermal plume, however a reverse relationship was observed at the lowest measurement height with the breathing function on. The existence of three areas influencing the thermal plume was revealed - head, torso, feet. For the lying manikin the air velocity increased by 6–13% when the breathing function was used in relation to non-breathing tests.