Top PDF Factors which Influence the Thermal Comfort Inside of Vehicles

Factors which Influence the Thermal Comfort Inside of Vehicles

Factors which Influence the Thermal Comfort Inside of Vehicles

There are several researches regarding the thermal comfort inside of vehicles in the scientific literature, but the number of studies which focus on analysing the factors is just a few. The attention of researchers is concentrate mainly on methods of evaluation the thermal comfort. Alahmer et al., in [10] reviewed vehicular thermal models comprehensively. In their study was discussed and analysed each of the thermal indices that were typically used in assessing in-cabin condition such as PMV index and PPD. In [11] the researchers investigates the analysis and modelling of vehicular thermal comfort parameters using a set of designed experiments aided by thermography measurements. In [9], discuss about the development of the thermal comfort zones during summer and winter periods inside vehicular cabins using two thermal modelling approaches: Berkeley and Fanger computation.
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Dominant causes of cooling in automobile vehicles for thermal comfort

Dominant causes of cooling in automobile vehicles for thermal comfort

Moreover, if we are talking about the thermal comfort in the vehicles‟ cockpit, other design parameters may influence the occupants‟ sensation in an unpredictable manner. One such parameter is the thermal sensation offered by the car seats, in terms of seat cover conduction coefficient, the environment inside the cabin is affected by a number of parameters that include: various structures of the surfaces and their temperatures, the local variation of air temperature, the speed distribution of air in an interior over complex geometry, relative humidity, solar radiation intensity and its reflection, the angle of incidence, type of clothing, etc. Moreover, some of these parameters are connected by relations that are still unknown. All these factors complicate both modelling and experimental approach attempts.
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Intelligent automotive thermal comfort control

Intelligent automotive thermal comfort control

Introduction 1.1 Automotive Air-Conditioning In the early stage of automotive history, the vehicle was just seen as an auxiliary tool for locomotion and for the transport of heavy goods [10]. The cabin spaces were open to the environment, requiring the passengers to choose their clothing according to the weather conditions. In the further automotive development and with increasing expectations of the customers in terms of comfort, closed passenger compartments were introduced which required heating and cooling of the interior. The first heating ventilation and air conditioning (HVAC) units consisted of some heat-able clay bricks and ice blocks for heating-up and cooling-down the passenger compartment. The ventilation was implemented by tilting windscreens or vents [24]. Nowadays the role of vehicles in our society has totally changed. They are no longer considered as a simple tool for locomotion. Mobility has become a substantial part in our society and advancements in technology have arose new appealing opportunities concerning automotive HVAC systems. Automotive HVAC units cannot be seen exclusively as luxury equipment, but have also a significant influence on road safety. Thermal discomfort can be a physical strain and leads to fatigue. Therefore, only a thermal balanced driver is considered to be observant [23]. Investigations in the US have shown that thermal discomfort is the third most common reason for road accidents [130].
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Roof designs and affecting thermal comfort factors in a typical naturally ventilated Malaysian mosque

Roof designs and affecting thermal comfort factors in a typical naturally ventilated Malaysian mosque

ii Abstract The local climate of Malaysia with high air temperature and relative humidity and inconsistent air movement throughout the day provides challenges for architects and designers to design a building including a mosque that can provide better indoor thermal condition. Thermally uncomfortable indoor environment in a typical Malaysian mosque can be sensed due to the poor attendance of believers during communal prayers conducted five times a day at the mosque. A study was carried out in four typical mosques in Malaysia to investigate the thermal comfort level together with what and how the thermal comfort factors affecting the condition. They study also looks at the influence of roof design of the mosque in affecting thermal condition inside the prayer hall since the roof design is a significant feature of the building not only as a filter to the outdoor climate but also as the identity of the building and the society. From the investigation, it has been revealed that air temperature is the primary factor in affecting thermal comfort. When the air temperature is at neutral or comfort temperature, the presence of other factors can be ignored. However, when the primary factor is no longer at its neutral condition, the secondary factors which are air movement and humidity will play their roles in influencing thermal comfort in naturally ventilated mosques in Malaysia. In many cases, air movement is always desirable and able to improve the thermal comfort level. Therefore, the need for the availability of air movement should be particularly considered in designing a mosque to ensure that the mosque is thermally comfortable. The research has also discovered that the pitched and doomed roofs have different abilities to control the distribution of air, for examples, the pitch roof mosque has the ability to circulate the air inside the prayer hall to achieve the equilibrium state whereas the domed roof mosque has the ability to stratify the air according to the temperature where the coolest air located at the lowest level of the space. With the pitch roof, a mosque is able to create air movement inside the space whereas the dome roof mosque will provide stagnant but cooler air at the active level due to the stratification process. Due to these findings, the pitched roof mosque is considered a better option for this climate for its ability to provide natural air circulation inside the space which is desirable by the users. With the understanding on the ability of the roof designs namely, domed and pitched roof in controlling air movement of the interior and the interdependencies of the main factors affecting thermal comfort, strategies for improvement on the design of the mosque can be made to achieve better indoor thermal condition of the prayer hall.
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Influence of tuck stitch in course direction on thermal comfort characteristics of layered knitted fabrics

Influence of tuck stitch in course direction on thermal comfort characteristics of layered knitted fabrics

3.4 Wicking Vertical Wicking Wicking is the spontaneous flow of liquid in a textile material, driven by capillary forces caused by wetting. All the bi-layer knitted fabrics show increasing trend in vertical wicking height for first 5 min. Figure 2 shows that vertical wicking height is higher for S18 followed by S14, S10 and S6 bi-layer knitted fabrics. The initial rate of water take-up in vertical wicking is higher for fabrics with less number of tuck stitch per unit area. S18 bi-layer knitted fabric with lower stitch density and thickness shows higher amount of water take-up compared to other bi-layer fabrics. The fabric characteristics and structure are the determining factors of the amount of water take-up.
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Influence of green spaces on outdoors thermal comfort-structured experiment in a Mediterranean climate

Influence of green spaces on outdoors thermal comfort-structured experiment in a Mediterranean climate

Figure 5. Thermal sensations frequency distribution: (a) in all locations; (b) by gender (M: male; F: female); (c) in structured experiment locations. 3.3. Influence of Microclimatic and Personal Variables on Personal Thermal Sensations To address the relation between personal thermal sensations and the meteorological conditions on the different locations, a multinomial logistic regression is applied. The data shows that only females felt Cold ( − 3), to avoid a quasi-complete separation bias, the corresponding two records were removed from the dataset. Table 2 presents the likelihood ratio test for the best results considering the variables and factors studied in this research (model fitting sig. <0.001; pseudo R-squared measures: Cox and Snell= 0.706; Nagelkerke = 0.734; McFadden = 0.374). These results show an adjustment (p <0.001) for some of the meteorological variables (covariates), namely air temperature (Ta), wind (V), and global radiation (St). From the personal factors tested, including age groups, only gender (GEN), considering a binary condition (0—male and 1—female), had an adjustment in the multinomial logistic regression model.
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Adaptive thermal comfort opportunities for dwellings:

Adaptive thermal comfort opportunities for dwellings:

There can be all kinds of factors that determine the differences in thermal preference such as age, posture or culture. A few of these aspects have been researched by testing subjects in different categories to be try to better predict thermal preference of a specific group. In various studies it has been concluded, that women are more sensitive to thermal discomfort, both hot and cold and that in general they prefer a slightly higher temperature (Karjalainen, 2012) and that they are more sensitive to local discomfort (Schellen et al., 2012). Furthermore, differences have been found in vulnerability between young adults and elderly. Aged people have a thermal sensation that is approximately 0.5 lower (according to the thermal sensation scale of Table 2.1) than their younger counterpart, which makes them particularly vulnerable to cold. Additionally they have been proven to recover from cold more slowly (Kingma et al.,2011). However, this doesn’t have an influence on the thermal sensation as felt during mild temperature drift (Schellen et al., 2010). Moreover, various studies point out that generally people prefer thermal circumstances at which they are exposed most. Needless to say this varies with lifestyle, occupation and culture. There have been insufficient studies to quantify these differences, but in a home one can expect these differences to be more prominent in offices and above all important to account for when designing the thermal comfort delivery system. It is difficult to quantify these differences, but it is sensible to expect that this can vary at least within the bandwidth usually assumed in which 85% of the occupants will be satisfied. This bandwidth is asymmetrical and approximately 6 K wide with a larger tolerance for temperatures above the comfort temperature. This research researches the required flexibility of the system to adapt to varying comfort demand.
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Urban heat island of Madrid and its influence over urban

thermal comfort

Urban heat island of Madrid and its influence over urban thermal comfort

(3) PhD. Architect. Research group Sustainable Architecture and Urban Planning (GIAU+S). Universidad Politécnica de Madrid Abstract. This work is part of the activities MODIFICA Project: Predictive model of the energy performance of residential buildings under conditions of urban heat island (BIA2013-41732-R). This project is funded by the Ministry of Economy and Competitiveness through the R + D + i, 2013 program, and the authors are involved in their development, together with the research group Bioclimatic Architecture in a Sustainable Environment - ABIO (UPM). The hypothesis of the project is the fact that the transformation of land for urban growth in the city of Madrid potentiates the effect of the urban heat island (UHI), which modifies substantially in the urban microclimate. The UHI is the result of the gradual replacement of natural surface by the urban area, whose surfaces absorb more solar radiation. This, coupled with other anthropogenic factors, increase the air temperature and cause an increase in local temperature. The consequence is a modification of the urban microclimate that affects to the comfort conditions in urban space and to the energy performance of buildings and, therefore, to the quality of life of the inhabitants.
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Does a neutral thermal sensation determine thermal comfort?

Does a neutral thermal sensation determine thermal comfort?

Other researchers defined thermal comfort through thermal neutrality. For example, McCartney and Nicol define the comfort temperature as ‘the indoor operative temperature at which an average subject will vote comfortable (or neutral) on the ASHRAE scale’ [10]. The ASHRAE Handbook 2009 states that ‘acceptability is determined by the percentage of occupants who have responded neutral or satisfied (0, +1, +2, or +3) with their thermal environment’ [2]. Although the application of thermal neutral sensation as the measure of thermal comfort has been criticized [11], many studies continue using this measure only. Followed by Humphreys’ question: ‘Do people want to feel neutral?’ [11]. De Dear highlights the fact that using the ‘neutral thermal sensation’ on the PMV seven-point scale ‘says nothing about whether the occupants are actually going to like it’ [12]. The combined application of thermal sensation and thermal preference has been suggested [11], however many researchers continue using one measure (thermal sensation) only. The few researchers, who apply thermal preference scale, mainly aim to clarify weather or not the occupant feels neutral, rather than investigating occupants’ desire to feel neutral in the first place. In this study, the connection of the occupant’s thermal comfort with thermal-neutrality was investigated in two separate contexts of Norwegian and British offices. Overall, the thermal environment of four office buildings were evaluated and 313 responses (three times a day) to the ASHRAE seven point scale thermal sensation, thermal preference, comfort, and satisfaction were recorded.
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Influence of tuck stitch in wale direction on thermal comfort characteristics of layered knitted fabrics

Influence of tuck stitch in wale direction on thermal comfort characteristics of layered knitted fabrics

higher water vapour permeability followed by S16, S8 and S4 bi-layer knitted fabrics. Moisture vapour transmission through S12 bi-layer knitted fabric is predominantly controlled by the geometric properties such as thickness and porosity 27 . Here, the thickness plays a vital role, because this ensures the distance through which the liquid moisture has to move from inner layer to outer layer. The distance between successive tuck stitch in S12 is higher than in S4 and S8 bi-layer knitted fabrics, thereby exhibiting lowest thickness and stitch density. This is because, the force exerted on loops will be less due to less number of tuck points in S12 bi-layer knitted fabric. The structures of S12 and S16 are slacker than S4 and S8 which is a compact structure. The reason is, with the same course repeat the distance between successive tuck stitches is high which seems unfastened, whereas in S4 bi-layer fabric, the distance between the successive tuck stitch is less and the fabric becomes tighter. This leads to higher thickness and mass per unit area and lower water vapour permeability. In S8 bi-layer knitted fabric, the number of tuck stitch per unit area is lower than in S4 bi-layer fabric. The S8 fabric seems less compact and hence shows higher water vapour permeability than S4 fabric.
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Does a neutral thermal sensation determine thermal comfort?

Does a neutral thermal sensation determine thermal comfort?

words ‘slightly warm’ to denote their thermal preference’ [22 ]. Finally, Humphreys questioned the accuracy and application of the findings in the field of thermal comfort that are on the basis of th e ‘neutral thermal sensation’ [11 ]. New scales were introduced to measure thermal comfort, such as ‘much too cool, too cool, comfor tably cool, neutral, comfortably warm, too warm and much too warm’ [23]. Humphreys explains ‘the need to ascertain more precisely the desired thermal sensation on the scale led researchers to supplement it with a scale of thermal preference, which asked people whether they would prefer to feel warmer or cooler, or whether they desired no change’ [11 ]. The use of two scales, such as thermal sensation and preference, has been recommended [7,16]. Different scales of thermal preference have been introduced, including the ASHRAE nine-point thermal sensation scale, the EN-ISO 4-point thermal comfort scale, Bedford scale for thermal comfort [24], Fox scale for thermal preference [25], the six-point comfort scale [26], and the three-point comfort scale [27]. The combination of thermal sensation and comfort is confusing and separate scales are preferable [18]. Currently some field studies of thermal comfort use a combination of the ASHRAE seven-point thermal sensation scale and the three-point McIntyre scale [28], as presented in Table 2 [29]. However, the later does not clarify how much cooler or warmer occupants prefer. Therefore, their desired thermal sensation cannot be analysed [11].
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Influence of the airflow in a solar passive building on the indoor air quality and thermal comfort levels

Influence of the airflow in a solar passive building on the indoor air quality and thermal comfort levels

One of the most important challenges of green buildings is simultaneously to reduce energy consumption and improve indoor air quality, maintaining the occupant's thermal comfort level within acceptable standards. The study by Persily and Emmerich [11] proposes some strategies to achieve these goals, namely increased envelope air tightness, heat recovery ventilation, demand controlled ventilation, and improved operations and maintenance, among others. Since 40% and 15% of the energy consumed in a building are, respectively, by Heating, Ventilating and Air Conditioning (HVAC) systems and lighting, some authors propose to reduce this energy by integrated control of active and passive sources of heating, cooling, lighting, shading and ventilation [13,21].
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Influence of the airflow in a solar passive building on the indoor air quality and thermal comfort levels

Influence of the airflow in a solar passive building on the indoor air quality and thermal comfort levels

Regarding some situations, measurements of indoor CO 2 concentrations can be used to assess indoor air quality and ventilation performance [ 44 , 46 , 47 ]. The relationship between CO 2 concentration and the ventilation rate, under steady-state conditions, is presented in ASHRAE Standard 62.1 [ 48 ], which also provides an equation that allows us to estimate the CO 2 generation rates in L/s per person. This is dependent on the metabolic rate, the respiratory level, the height and body mass of the person, as shown by Persily and de Jonge [ 49 ]. Normally, an indicator of an acceptable indoor air quality is a CO 2 concentration below 1000 ppm [ 48 ]. However, associations between CO 2 concentrations and occupant perceptions of the indoor environment are more complex because they combine several issues including the comfort impacts of CO 2 itself, associations between the CO 2 concentrations and other contaminants, and the relationship between CO 2 and ventilation [ 50 ].
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Thermal comfort study for student laboratory

Thermal comfort study for student laboratory

The study was carried out to show the thermal comfort knowledge, which including the Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD), the personal factors and environmental parameters which affect the thermal comfort in laboratory. The author also had learned to use the equipment for measuring the thermal comfort in laboratory. Through the study, author can improve his knowledge on thermal comfort and gain an experience on how to conduct measurement of thermal comfort. From the knowledge experience, it is very useful when working in factory environments for author future career.
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Thermal Comfort Assesment In Manufacturing Environment

Thermal Comfort Assesment In Manufacturing Environment

Technology in achieving thermal comfort in buildings has been made to give comfort to all and maintaining health and improving the quality of work. HVAC (heating, ventilation and air condition) has been made for the design of industrial buildings and large offices where conditions are safe and healthy buildings are arranged with reference to temperature and humidity using the fresh air of nature. The HVAC industry is a worldwide enterprise, with roles including operation and maintenance, system design and construction, equipment manufacturing and sales, and in education and research. The HVAC industry was historically regulated by the manufacturers of HVAC equipment, but Regulating and Standards organizations such as HARDI, ASHRAE, SMACNA, ACCA, Uniform Mechanical Code, international Mechanical Code, and AMCA have been established to support the industry and encourage high standards and achievement.
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Human thermal comfort in tropical climates

Human thermal comfort in tropical climates

Body tem perature is the result of a fine heat balance betw een heat gained by the body and heat dissipated from it. Two sources which contribute to heat accum ulation are internal and external heat. The external heat is the h eat from the therm al environm ent. M etabolic processes are the m ain source for internal heat p roduction w ithin the body. The h u m an body transform s chemical energy derived from the oxidation of carbohydrates, fats an d proteins into m echanical energy. Since the efficiencies of these processes are relatively low, at 10% - 20% [8], m ost of the energy produced is tran sfo rm ed into heat. The m etabolic heat p ro d u ctio n can th u s be calculated by subtracting the external mechanical work, W, from the total m etabolic energy production, M, as (M - W). This net heat is either stored, causing the body tem perature to rise, or is dissipated to the environm ent th ro u g h the skin surface and the respiratory tract.
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Assessment of thermal comfort in transitional spaces

Assessment of thermal comfort in transitional spaces

7. CONCLUSIONS This research paper provided the basic knowledge of transitional spaces and evaluate the current thermal comfort theories. Field study and surveys were conducted to investigate the thermal performance of semi-opened and fully enclosed transitional spaces in HKU and seasonal variations of subjective responses. It was found that an opened area is easily influenced by variable weather conditions as it is close to natural environment while an enclosed one is totally separated from the exterior environment and commonly air- conditioned. This may lead to different subjective thermal responses in these two types of spaces. It was also discovered that people can accept wider thermal environment in transitional spaces and their thermal response varies with dressing, activity level, past thermal experience and prior thermal preference. It is believed that the current comfort standards and criteria are not designed for transitional spaces. The proposed thermal comfort ranges for transitional spaces were examined using modified adaptive comfort model. This could be used to consider possible changes to the current design guidelines and standards. If the transitional spaces are designed with appropriate energy saving strategies such as passive design, hybrid ventilation and flexible HVAC controls, it can help achieve more energy efficient and healthy buildings in the future.
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Dominant factors which influence wheat production in South Africa

Dominant factors which influence wheat production in South Africa

South Africa has predominantly been making use of a centralized storage system. South Africa’s wheat storage system has been influenced by the commercial development of South Africa’s wheat industry. There are differences between the grain-storage systems of the Old World (Europe and the Middle East) and those of the New World (North and South American countries, Australia and South Africa). As with ancient subsistence farming practices, the largest proportion of the harvest is stored on farms in the Old World. In these countries a central storage system developed only when the grain trade grew and developed. The primary goal of central grain storage and handling systems in these countries is trade, not storage. In some younger countries, such as Australia, Argentina, Canada and South Africa, commercial wheat production developed in conjunction with central marketing and a central storage system. However, unlike South Africa, effort was also put into the development of extensive, effective farm storage systems by countries such as Australia, Argentina and Canada; although a central marketing system was also used in the past. The main reason for this difference is the shortage of farm labourers in these countries. South Africa had large numbers of unskilled labourers, who were used to transport grain directly after harvesting from the fields to a central silo. The incentive to do so was rooted in the central marketing system, according to which the farmers received their remuneration at a set price within a few weeks after delivery to the central marketing body.
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The factors which influence the selection of physical targets by terrorist groups

The factors which influence the selection of physical targets by terrorist groups

thesis The Political Masters: Use of Terrorism in Italys London: Constable, 1991, is that many right-wing terrorist in Italy directed groups and were manipulated by the Italian to a degr[r]

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Future context for thermal comfort: Impact of a changing climate on energy demand and human thermal comfort

Future context for thermal comfort: Impact of a changing climate on energy demand and human thermal comfort

Typical climate conditions for the 20 th century may not provide the full range of temperature, precipitation and humidity extremes that likely will be encountered for the built environment of the 21 st century. It is important to understand the impact of changing climate on building energy consumption, building design and thermal comfort in existing buildings. Therefore sensitivity studies were conducted for an exemplary location: Mason City Iowa. Based on future scenario climates for the period 2040-2070 produced by eight global/regional climate models, future typical meteorological year (FTMY) data sets were developed for this location and basic energy calculations were conducted in Energy Plus for a typical residence as well as the US DOE commercial reference buildings. Our results show that the increase in energy consumption resulting from projected change in climate over the next 50 year at this location results primarily from responding to an increase in ambient humidity in summer. Therefore, the largest energy cost for maintaining desired levels of health and comfort in the future at this location will be attributed to managing higher ambient humidity levels. Put another way, in order to reduce energy consumption by buildings at this location in the future, priority should be given to finding innovative ways to manage humidity or to adapt.
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