scholarly journals Evaluation and modelling the micro-bioclimatological conditions of a popular playground in Szeged, Hungary

2013 ◽  
Vol 4 (1) ◽  
pp. 57-61 ◽  
Author(s):  
L. A. Égerházi ◽  
N. Kántor ◽  
T. Gál
Keyword(s):  
Land Cover ◽  
Thermal Comfort ◽  
Meteorological Parameters ◽  
Thermal Sensation ◽  
Thermal Conditions ◽  
Radiation Environment ◽  
Mean Radiant Temperature ◽  
Predicted Mean Vote ◽  
Typical Summer ◽  
Radiant Temperature

Abstract This paper presents a thermal comfort study of a popular playground in Szeged, Hungary in order to find its optimal land cover and vegetation options. For this assessment simulated micro- and bioclimatological conditions recorded on a typical summer day (12th July 2011) were analysed. The thermal and radiation features of the study area were quantified by two biometeorological indices, Predicted Mean Vote (PMV) and Mean Radiant Temperature (Tmrt). For the simulation of the meteorological parameters and the bioclimate indices, ENVI-met microclimate model was used. The results confirmed that the modelled areas with different land cover provide a variety of thermal conditions for the visitors; moreover, human thermal sensation was significantly affected by the change of the radiation environment.

scholarly journals The most problematic variable in the course of human-biometeorological comfort assessment — the mean radiant temperature

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Noémi Kántor ◽  
János Unger
Keyword(s):  
Thermal Comfort ◽  
Short Wave ◽  
Urban Environments ◽  
Outdoor Thermal Comfort ◽  
Radiation Environment ◽  
Wave Radiation ◽  
Mean Radiant Temperature ◽  
Radiation Fluxes ◽  
The Mean ◽  
Radiant Temperature

AbstractThis paper gives a review on the topic of the mean radiant temperature Tmrt, the most important parameter influencing outdoor thermal comfort during sunny conditions. Tmrt summarizes all short wave and long wave radiation fluxes reaching the human body, which can be very complex (variable in spatial and also in temporal manner) in urban settings. Thermal comfort researchers and urban planners need easy and sound methodological approaches to assess Tmrt. After the basics of the Tmrt calculation some of the methods suitable for obtaining Tmrt also in urban environments will be presented.. Two of the discussed methods are based on instruments which measure the radiation fluxes integral (globe thermometer, pyranometer-pyrgeometer combination), and three of the methods are based on modelling the radiation environment with PC software (RayMan, ENVI-met and SOLWEIG).

scholarly journals Evaluasi Kenyamanan Termal Ruang Sekolah SMA Negeri di Kota Padang

2016 ◽  
Vol 12 (1) ◽  
pp. 310 ◽  
Author(s):  
Lusi Susanti ◽  
Nike Aulia
Keyword(s):  
Thermal Comfort ◽  
Climatic Factors ◽  
Thermal Conditions ◽  
Comfort Level ◽  
Air Humidity ◽  
Student Body ◽  
Predicted Mean Vote ◽  
Individual Vote ◽  
The Individual ◽  
Radiant Temperature

This research aims to determine thermal conditions and sensation of thermal comfort in classrooms of high schools in Padang. This study was conducted in 11 State Senior High School (SMA) represented 11 districts in Padang. About 10% of total student body in each schools were participated in this study to vote thermal comfort questioners. To determine thermal comfort level in this study, PMV (Predicted mean Vote) and PPD (Predicted Percentage of dissatisfied) method were used according to standard of thermal comfort in ASHRAE 55-2005 and ISO 7730. PMV method is used to determine scope of situation in the environment that scaled from +3 for very hot until -3 for very cold, and PPD is a method to calculate the number of human (in percentage) dissatisfied with the environment. Calculated PMV and PPD were compared with PMV and PPD resulted from individual vote from questionnaires. Result showed that in general, thermal conditions in classrooms had air temperature and radiant temperature from 27oC – 30oC, air humidity from 68% - 80%, and wind speed of 0 m/s. Calculated PMV from this condition were ranging from +1 slightly warm) until +2 (warm) while PPD calculated greater than 20%. Compared with calculated PMV and PPD values, the individual vote showed values from +0,5 (neutral) until +1 (slightly warm) while PPD values of individual vote greater than 20% except for SMA 2 and SMA 11 Padang. It is concluded that improvements of indoor thermal conditions have to make inside classrooms as well as landscape outside in order to improve thermal comfort level of students during learning and teaching.Keywords: Thermal Comfort, PMV (Predicted Mean Vote), PPD (Predicted Percentage ofDissatisfied), climatic factors, SMA

scholarly journals Membrane-assisted radiant cooling for expanding thermal comfort zones globally without air conditioning

2020 ◽  
Vol 117 (35) ◽  
pp. 21162-21169 ◽  
Author(s):  
Eric Teitelbaum ◽  
Kian Wee Chen ◽  
Dorit Aviv ◽  
Kipp Bradford ◽  
Lea Ruefenacht ◽  
...  
Keyword(s):  
Water Supply ◽  
Thermal Comfort ◽  
Cooling System ◽  
Thermal Sensation ◽  
Dew Point ◽  
Mean Radiant Temperature ◽  
Radiation Exchange ◽  
Radiant Cooling ◽  
Chilled Water ◽  
Radiant Temperature

We present results of a radiant cooling system that made the hot and humid tropical climate of Singapore feel cool and comfortable. Thermal radiation exchange between occupants and surfaces in the built environment can augment thermal comfort. The lack of widespread commercial adoption of radiant-cooling technologies is due to two widely held views: 1) The low temperature required for radiant cooling in humid environments will form condensation; and 2) cold surfaces will still cool adjacent air via convection, limiting overall radiant-cooling effectiveness. This work directly challenges these views and provides proof-of-concept solutions examined for a transient thermal-comfort scenario. We constructed a demonstrative outdoor radiant-cooling pavilion in Singapore that used an infrared-transparent, low-density polyethylene membrane to provide radiant cooling at temperatures below the dew point. Test subjects who experienced the pavilion (n= 37) reported a “satisfactory” thermal sensation 79% of the time, despite experiencing 29.6 ± 0.9 °C air at 66.5 ± 5% relative humidity and with low air movement of 0.26 ± 0.18 m⋅s−1. Comfort was achieved with a coincident mean radiant temperature of 23.9 ± 0.8 °C, requiring a chilled water-supply temperature of 17.0 ± 1.8 °C. The pavilion operated successfully without any observed condensation on exposed surfaces, despite an observed dew-point temperature of 23.7 ± 0.7 °C. The coldest conditions observed without condensation used a chilled water-supply temperature 12.7 °C below the dew point, which resulted in a mean radiant temperature 3.6 °C below the dew point.

scholarly journals Modeling Mean Radiant Temperature Distribution in Urban Landscapes Using DART

2021 ◽  
Vol 13 (8) ◽  
pp. 1443
Author(s):  
Maria Angela Dissegna ◽  
Tiangang Yin ◽  
Hao Wu ◽  
Nicolas Lauret ◽  
Shanshan Wei ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Thermal Comfort ◽  
Leaf Area ◽  
Remote Sensing Data ◽  
Outdoor Thermal Comfort ◽  
Transfer Model ◽  
Mean Radiant Temperature ◽  
Area Index ◽  
Sensing Data ◽  
Radiant Temperature

The microclimatic conditions of the urban environment influence significantly the thermal comfort of human beings. One of the main human biometeorology parameters of thermal comfort is the Mean Radiant Temperature (Tmrt), which quantifies effective radiative flux reaching a human body. Simulation tools have proven useful to analyze the radiative behavior of an urban space and its impact on the inhabitants. We present a new method to produce detailed modeling of Tmrt spatial distribution using the 3-D Discrete Anisotropic Radiation Transfer model (DART). Our approach is capable to simulate Tmrt at different scales and under a range of parameters including the urban pattern, surface material of ground, walls, roofs, and properties of the vegetation (coverage, shape, spectral signature, Leaf Area Index and Leaf Area Density). The main advantages of our method are found in (1) the fine treatment of radiation in both short-wave and long-wave domains, (2) detailed specification of optical properties of urban surface materials and of vegetation, (3) precise representation of the vegetation component, and (4) capability to assimilate 3-D inputs derived from multisource remote sensing data. We illustrate and provide a first evaluation of the method in Singapore, a tropical city experiencing strong Urban Heat Island effect (UHI) and seeking to enhance the outdoor thermal comfort. The comparison between DART modelled and field estimated Tmrt shows good agreement in our study site under clear-sky condition over a time period from 10:00 to 19:00 (R2 = 0.9697, RMSE = 3.3249). The use of a 3-D radiative transfer model shows promising capability to study urban microclimate and outdoor thermal comfort with increasing landscape details, and to build linkage to remote sensing data. Our methodology has the potential to contribute towards optimizing climate-sensitive urban design when combined with the appropriate tools.

scholarly journals Thermal Comfort and Sleep Quality of Indonesian Students Living in Japan during Summer and Winter

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 326
Author(s):  
Wiwik Budiawan ◽  
Kazuyo Tsuzuki
Keyword(s):  
Sleep Quality ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Thermal Conditions ◽  
Physical Conditions ◽  
Subjective Sleepiness ◽  
Adaptive Action ◽  
Quality Sleep ◽  
Sleep Parameters

Thermal comfort is crucial in satisfaction and maintaining quality sleep for occupants. In this study, we investigated the comfort temperature in the bedroom at night and sleep quality for Indonesian students during summer and winter. Eighteen male Indonesian students aged 29 ± 4 years participated in this study. The participants had stayed in Japan for about six months. We evaluated the sleep parameters using actigraphy performed during summer and winter. All participants completed the survey regarding thermal sensation, physical conditions, and subjective sleepiness before sleep. The temperature and relative humidity of participants’ bedrooms were also measured. We found that the duration on the bed during winter was significantly longer than that during summer. However, sleeping efficiency during winter was significantly worse than that during summer. The bedroom temperature of the participants was in the range of comfort temperature in Indonesia. With the average bedroom air temperature of 22.2 °C, most of the participants still preferred “warm” and felt “slightly comfortable” during winter. The average comfort temperature each season calculated using the Griffiths method was 28.1 °C during summer and 23.5 °C during winter. In conclusion, differences in adaptive action affect bedroom thermal conditions. Furthermore, habits encourage the sleep performance of Indonesian students.

scholarly journals Analysis of Urban Greening Scenarios for Improving Outdoor Thermal Comfort in Neighbourhoods of Lecce (Southern Italy)

Climate ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 116
Author(s):  
Elisa Gatto ◽  
Fabio Ippolito ◽  
Gennaro Rispoli ◽  
Oliver Savio Carlo ◽  
Jose Luis Santiago ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Urban Environment ◽  
Southern Italy ◽  
Hot Spot ◽  
Outdoor Thermal Comfort ◽  
Urban Greening ◽  
Urban Microclimate ◽  
Field Campaigns ◽  
Typical Summer ◽  
Radiant Temperature

This study analyses the interactions and impacts between multiple factors i.e., urban greening, building layout, and meteorological conditions that characterise the urban microclimate and thermal comfort in the urban environment. The focus was on two neighbourhoods of Lecce city (southern Italy) characterised through field campaigns and modelling simulations on a typical hot summer day. Field campaigns were performed to collect greening, building geometry, and microclimate data, which were employed in numerical simulations of several greening scenarios using the Computational Fluid Dynamics-based and microclimate model ENVI-met. Results show that, on a typical summer day, trees may lead to an average daily decrease of air temperature by up to 1.00 °C and an improvement of thermal comfort in terms of Mean Radiant Temperature (MRT) by up to 5.53 °C and Predicted Mean Vote (PMV) by up to 0.53. This decrease is more evident when the urban greening (in terms of green surfaces and trees) is increased by 1266 m2 in the first neighbourhood and 1988 m2 in the second one, with respect to the current scenario, proving that shading effect mainly contributes to improving the urban microclimate during daytime. On the contrary, the trapping effect of heat, stored by the surfaces during the day and released during the evening, induces an increase of the spatially averaged MRT by up to 2 °C during the evenings and a slight deterioration of thermal comfort, but only locally where the concentration of high LAD trees is higher. This study contributes to a better understanding of the ecosystem services provided by greening with regard to microclimate and thermal comfort within an urban environment for several hours of the day. It adds knowledge about the role of green areas in a Mediterranean city, an important hot spot of climate change, and thus it can be a guide for important urban regeneration plans.

scholarly journals How Can We Adapt Thermal Comfort for Disabled Patients? A Case Study of French Healthcare Buildings in Summer

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4530
Author(s):  
Youcef Bouzidi ◽  
Zoubayre El Akili ◽  
Antoine Gademer ◽  
Nacef Tazi ◽  
Adil Chahboun
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Linear Regression Analysis ◽  
Environmental Parameters ◽  
Physical Parameters ◽  
Mean Radiant Temperature ◽  
Operative Temperature ◽  
Neutral Temperature ◽  
Radiant Temperature

This paper investigates adaptive thermal comfort during summer in medical residences that are located in the French city of Troyes and managed by the Association of Parents of Disabled Children (APEI). Thermal comfort in these buildings is evaluated using subjective measurements and objective physical parameters. The thermal sensations of respondents were determined by questionnaires, while thermal comfort was estimated using the predicted mean vote (PMV) model. Indoor environmental parameters (relative humidity, mean radiant temperature, air temperature, and air velocity) were measured using a thermal environment sensor during the summer period in July and August 2018. A good correlation was found between operative temperature, mean radiant temperature, and PMV. The neutral temperature was determined by linear regression analysis of the operative temperature and Fanger’s PMV model. The obtained neutral temperature is 23.7 °C. Based on the datasets and questionnaires, the adaptive coefficient α representing patients’ capacity to adapt to heat was found to be 1.261. A strong correlation was also observed between the sequential thermal index n(t) and the adaptive temperature. Finally, a new empirical model of adaptive temperature was developed using the data collected from a longitudinal survey in four residential buildings of APEI in summer, and the obtained adaptive temperature is 25.0 °C with upper and lower limits of 24.7 °C and 25.4 °C.

Design Range of Indoor Relative Humidity in Radiant Cooling Environment

2011 ◽  
Vol 243-249 ◽  
pp. 4905-4908
Author(s):  
Xue Min Sui ◽  
Xu Zhang ◽  
Guang Hui Han
Keyword(s):  
Relative Humidity ◽  
Thermal Comfort ◽  
Mean Radiant Temperature ◽  
Design Standards ◽  
Human Thermal Comfort ◽  
Radiant Cooling ◽  
Climate Parameter ◽  
Radiant Temperature ◽  
Thermal Comfort Model ◽  
The Impact

Relative humidity is an important micro-climate parameter in radiant cooling environment. Based on the human thermal comfort model, this paper studied the effect on PMV index of relative humidity, and studied the relationship of low mean radiant temperature and relative humidity, drew the appropriate design range of indoor relative humidity for radiant cooling systems.The results show that high relative humidity can compensate for the impact on thermal comfort of low mean radiant temperature, on the premise of achieving the same thermal comfort requirements. However, because of the limited compensation range of relative humidity, together with the constraints for it due to anti-condensation of radiant terminal devices, the design range of relative humidity should not be improved, and it can still use the traditional air-conditioning design standards.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals A climatic study of an urban green space: the Gulbenkian Park in Lisbon (Portugal)

Finisterra ◽  
2012 ◽  
Vol 42 (84) ◽  
Author(s):  
Henrique Andrade ◽  
Rute Vieira
Keyword(s):  
Solar Radiation ◽  
Thermal Comfort ◽  
Green Space ◽  
Urban Green Space ◽  
Mean Radiant Temperature ◽  
Climatic Parameters ◽  
Incident Solar Radiation ◽  
Urban Green ◽  
Isolated Trees ◽  
Radiant Temperature

Measurements of various climatic parameters were carried out in an average-sized green space in the centre of Lisbon (the Fundação Calouste Gulbenkian Park). The aims consisted of assessing the thermal differentiation between the park and the surrounding built-up area and analysing the microclimatic patterns within the park itself. The main results demonstrate that the park is cooler than the built-up area in all the seasons and both during the daytime and at night, but especially so in the daytime during the summer. The most significant microclimatic contrasts were found to occur with respect to solar radiation and mean radiant temperature, with consequences upon the level of thermal comfort. The structure of the vegetation was also found to have a significant microclimatic influence, since the reduction in the level of incident solar radiation brought on by the presence of groups of trees was much larger than that associated with isolated trees.

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