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Lee, Dong-Seok, and Jae-Hun Jo. "Pan–Tilt IR Scanning Method for the Remote Measurement of Mean Radiant Temperatures at Multi-Location in Buildings." Remote Sensing 13, no. 11 (May 31, 2021): 2158. http://dx.doi.org/10.3390/rs13112158.
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The mean radiant temperature (MRT) is an indicator for evaluating the radiant heat environment near occupants and is determined by the radiant heat exchange between the occupants and their surroundings. To control various heating and cooling systems according to the occupants’ thermal comfort, it is essential to consider MRTs in the real-time evaluation of thermal environment. This study proposes a pan–tilt infrared (IR) scanning method to estimate the MRTs at multiple occupant locations in real buildings. The angle factor was calculated by defining the specific classification criteria for dividing the entire indoor surface into sub-surfaces. The coupling IR camera and pan–tilt motor were applied to enable storing data pairs of IR thermal image frame (IR image frame) and pan–tilt angle so each surface area taken by the IR camera can have its direction information. The measurement method of the mean surface temperature using the pan–tilt IR system was presented. The pan–tilt IR system hardware and MRT monitoring software were developed. An experiment was performed to verify the applicability of the proposed pan–tilt IR scanning method. By comparing the surface temperatures measured using a contact thermometer and the proposed IR system, the contact thermometer could cause inaccurate measurement of surfaces with a non-uniform distribution of temperature. The difference between surface temperatures increased by up to 15 °C and, accordingly, the MRT distributions differed by up to 6 °C within the same space. The proposed IR scanning method showed good applicability in various aspects. This paper reports that the MRT has a significant effect on the occupants’ thermal comfort and also suggests considering MRTs in the real-time evaluation of thermal environment to control various heating and cooling systems appropriately.
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Guo, Qianwen, Ryozo Ooka, Wonseok Oh, Wonjun Choi, and Doyun Lee. "Effect of insulation on indoor thermal comfort in a detached house with a floor heating system." E3S Web of Conferences 111 (2019): 02049. http://dx.doi.org/10.1051/e3sconf/201911102049.
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Appropriate insulation materials, with unique physical properties and of moderate thickness, are essential for energy savings in residential buildings. However, the impact of thermal insulation on indoor thermal comfort with floor heating systems has not been studied extensively. In this study, simulations of a typical Japanese detached house were conducted with four different thicknesses of insulation material in the walls, ceiling, and floor to estimate the mean air temperature (MAT), mean radiant temperature (MRT), floor temperature, predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD). The results showed that increasing the thickness of thermal insulation increased the MAT and MRT by 1.4 – 4.0 ℃ and 1.3 – 4.4 ℃, respectively. Moreover, as the thickness of the thermal insulation increased, the floor temperature rose and exhibited smaller fluctuations. Finally, it was found that increasing the thickness of thermal insulation improved the indoor thermal comfort environment, as evidenced by an increase in the PMV from –1.0 to 0.3, and a decrease in the PPD from 25.1% to 9.5%.
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Kang, Yong-Kwon, Beom-Jun Kim, Soo-Yeol Yoon, and Jae-Weon Jeong. "Experimental evaluation of phase change material in radiant cooling panels integrated with thermoelectric modules." E3S Web of Conferences 111 (2019): 01002. http://dx.doi.org/10.1051/e3sconf/201911101002.
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This study proposes a phase change material for use in radiant cooling panels integrated with thermoelectric modules (PCM–TERCP) and evaluates its performance characteristics during the solidification and melting process of phase change materials in design conditions. The PCM–TERCP consists of phase change materials (PCMs), thermoelectric modules (TEMs), and aluminumpanels. TEMs operate to freeze the PCM, and PCM stores the cooling thermal energy to maintain the constant surface temperature of the panel for radiant cooling. The main purpose of thermal energy storage systems is the shift of the electricity consumption from day-time to night-time during the summer season. Therefore, PCM–TERCP can implement off-peak operation according to which energy is expected to be saved. The melting temperature of PCM and the target surface temperatures of the bottom panels of PCM–TERCP were designed to be 16°C. Additionally, the room temperature and mean radiant temperature (MRT) was set to 24°C, while the thickness of the PCM pouch was 10 mm. As a result, the solidification process required 4 h and the total input power was 0.528 kWh. Correspondingly, the melting process can operate passively over a period of 4 h. In most cases, the operating temperature was lower than 19°C, which validates the temperature response of PCM–TERCP.
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Sugiono, Sugiono, Andyka Kusuma, Rio Lukodono, Siti Nurlaela, and Achmad Wicaksono. "Impact of elevated outdoor MRT station towards passenger thermal comfort: A case study in Jakarta MRT." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 29, no. 1 (April 4, 2020): 93–107. http://dx.doi.org/10.22630/pniks.2020.29.1.9.
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Comfort of the train passengers is the main priority of modern mass rapid transit (MRT) management. Objective of this paper is to investigate the thermal comfort of the elevated MRT station in tropical climate. The first step of this study was to conduct literature review on human thermal comfort, environment ergonomics, computational fluid dynamic (CFD), computational aeroacoustics (CAA), and predicted mean vote (PMV). Air quality in elevated MRT station was measured based on several parameters: relative humidity, wind speed, temperature, and wind direction. A 3D model of MRT designed was used to describe existing condition prior to simulations with CFD and CAA softwares. Predicted mean vote is arranged based on the value of metabolism, wind speed, ambient temperature, mean radiant temperature, amount of insulation from clothing, and relative humidity. Whereas predicted percentage of dissatisfi ed (PPD) can be derived from PMV calculations. The analysis shows that the average PMV of existing condition for elevated outdoor MRT station is 3.6 (extremely hot) with PPD is 100% (all passengers felt discomfort). Some recommendations to reduce heat stress were addressed such as: adding plant, changing materials of the MRT station, and change the design of the elevated MRT station. Modifying open elevated MRT station into indoor elevated MRT station with installing six units of AC (2pk, ±23°C) can improve air quality and maintain the thermal comfort scale of PMV to be –0.04 (comfort) with PPD of < 8%. Based on the analysis, it can be concluded that the most suitable design for elevated MRT station in tropical climate (hot and humid) is indoor MRT station with pay attention to both direct and indirect heat exposure that hit the station.
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Lee, Chun-Seok, and Nam-Hyung Ryu. "The Influence of the Landscaping Shade Membrane's Brightness on the Mean Radiant Temperature(MRT) of Summer Outdoor." Journal of the Korean Institute of Landscape Architecture 43, no. 5 (October 31, 2015): 65–73. http://dx.doi.org/10.9715/kila.2015.43.5.065.
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Zulfiana, Indah Sari. "KENYAMANAN LINGKUNGAN TERMAL RUANG KULIAH (C4) FAKULTAS TEKNIK UNIVERSITAS ICHSAN GORONTALO." JTT (Jurnal Teknologi Terpadu) 7, no. 1 (April 26, 2019): 66–69. http://dx.doi.org/10.32487/jtt.v7i1.637.
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Kenyamanan termal suatu ruang kuliah diperlukan untuk mendukung proses penerimaan pembelajaran oleh mahasiswa. Penelitian ini bertujuan untuk mengetahui kenyamanan lingkungan termal pada ruang kuliah (C4) Fakultas Teknik Universitas Ichsan Gorontalo dengan menggunakan sistem penghawaan buatan (AC). Kuisioner dibagikan kepada 30 mahasiswa Teknik Arsitektur dengan menggunakan sensasi termal ASHRAE, penerimaan kondisi termal serta preferensi termal. Bersamaan dengan itu dilakukan pengukuran lapangan untuk mengetahui temperatur udara (Ta), kelembaban relatif (RH), Mean Radiant Temperature (MRT) dan kecepatan udara (Va). Hasil penelitian menunjukkan bahwa 50% mahasiswa memilih agak dingin pada sensasi termalnya sedangkan 97% dapat menerima keadaan termal ruang, dan hampir 70% mahasiswa tidak menginginkan perubahan kondisi termal pada ruangan tersebut.
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Lyu, Tong, Riccardo Buccolieri, and Zhi Gao. "A Numerical Study on the Correlation between Sky View Factor and Summer Microclimate of Local Climate Zones." Atmosphere 10, no. 8 (July 29, 2019): 438. http://dx.doi.org/10.3390/atmos10080438.
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In the context of urbanization, research on urban microclimate and thermal comfort has become one of the themes of eco-city design. Sky view factor (SVF), one of the parameters of urban spatial form, combines multiple morphological information, such as plane opening, aspect ratio, and building density and has an important impact on the urban microclimate. However, there is still no clear research conclusion on the correlation between SVF and microclimate. In this paper, nine Local Climate Zone (LCZ) models are used and typical summer meteorological conditions of Nanjing are applied as an attempt to partially fill this gap. The calculated microclimate and thermal comfort indices include air temperature (AT), surface temperature (ST), relative humidity (RH), wind speed (WS), mean radiant temperature (MRT), and predicted mean vote (PMV). Results show that the local effect of urban morphology on thermal comfort can be retrieved from the use of comprehensive parameters such as SVF (which takes into account the building height, layout, and density) whose distribution in the investigated models showed to be correlated with MRT, so did PMV under low wind speed conditions.
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de Lieto Vollaro, R., A. Vallati, and S. Bottillo. "Differents Methods to Estimate the Mean Radiant Temperature in an Urban Canyon." Advanced Materials Research 650 (January 2013): 647–51. http://dx.doi.org/10.4028/www.scientific.net/amr.650.647.
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The mean radiant temperature is one of the meteorological key parameters governing human energy balance and the thermal comfort of human body. This variable can be considered as the sum of all direct and reflected radiation fluxes to which the human body is exposed. After the basics of the Tmrt calculation a comparison between two methods suitable for obtaining Tmrt in a street canyon will be presented. One of the discussed methods of obtaining Tmrt is based on the utilization of a globe thermometer. The other method is the radiation environment simulation through three PC software (RayMan, ENVI-met and SOLWEIG).
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Takebayashi, Hideki, Mai Okubo, and Hiroki Danno. "Thermal Environment Map in Street Canyon for Implementing Extreme High Temperature Measures." Atmosphere 11, no. 6 (May 26, 2020): 550. http://dx.doi.org/10.3390/atmos11060550.
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The thermal environment map in street canyon is derived by using GIS building data and more detailed calculation, and its effectiveness is considered for implementing extreme high temperature measures. The influence of mean radiant temperature (MRT) is more dominant than the wind velocity on the distribution of standard new effective temperature (SET*) on the typical summer day in street canyon in the urban area of Kobe city, and the solar radiation shading is more effective in suppressing the rise of SET* in the daytime than improving the land coverage. The following strategy of extreme high temperature measures is derived by considering the thermal environment map in street canyon. Pedestrians may find the shaded places on the north-south road until 10:00 a.m. and after 3:00 p.m., due to the eastern building’s shade in the morning and the western building’s shade in the afternoon.
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Lee, Chun-Seok, and Nam-Hyung Ryu. "The Comparison of the Solar Radiation and the Mean Radiant Temperature (MRT) under the Shade of Landscaping Trees in Summertime." Journal of the Korean Institute of Landscape Architecture 42, no. 5 (October 31, 2014): 22–30. http://dx.doi.org/10.9715/kila.2014.42.5.022.
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Yang, Wei, Yao Lin Lin, and Nyuk Hien Wong. "The Effect of Urban Design on Outdoor Thermal Environment in a Central Business District Area in Singapore." Advanced Materials Research 1073-1076 (December 2014): 1428–32. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.1428.
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Outdoor thermal environment in urban spaces is important for people to enjoy the urban environment. This paper investigated the effect of urban design on outdoor thermal environment in an urban street in the central business district in Singapore, focusing on street orientation and height-to-width ratio. The microclimatic parameters of different street design scenarios were determined by ENVI-met numerical simulation. Field measurement was conducted to validate the results from the numerical simulation and they were in good agreement. For different design scenarios, it is found that (1) The air temperature differences did not exceed 0.8°C; (2) The mean radiant temperature differences could exceed 40°C; (3) The maximum wind speed difference was 0.6 m/s; (4) No distinct relative humidity differences could be found. The results show that shading is the key strategy for improving outdoor thermal environment in Singapore because it leads to reduction on the air temperature and mean radiant temperature simultaneously. N-S orientated street had the best thermal environment condition.Outdoor thermal environment in urban spaces is important for people to enjoy the urban environment. This paper investigated the effect of urban design on outdoor thermal environment in an urban street in the central business district in Singapore, focusing on street orientation and height-to-width ratio. The microclimatic parameters of different street design scenarios were determined by ENVI-met numerical simulation. Field measurement was conducted to validate the results from the numerical simulation and they were in good agreement. For different design scenarios, it is found that (1) The air temperature differences did not exceed 0.8°C; (2) The mean radiant temperature differences could exceed 40°C; (3) The maximum wind speed difference was 0.6 m/s; (4) No distinct relative humidity differences could be found. The results show that shading is the key strategy for improving outdoor thermal environment in Singapore because it leads to reduction on the air temperature and mean radiant temperature simultaneously. N-S orientated street had the best thermal environment condition. Shading achieved by means of high aspect ratios can improve thermal environment at street level.
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Błażejczyk, Krzysztof, and Magdalena Kuchcik. "UTCI applications in practice (methodological questions)." Geographia Polonica 94, no. 2 (2021): 153–65. http://dx.doi.org/10.7163/gpol.0198.
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UTCI, although it was developed with the participation of scientists from 22 countries, it has shortcomings and people using it face various obstacles. The difficulties include wide range of issues: from different availability of meteorological data in individual countries, through the kind of air temperature which should be properly used in calculations, or the need of recalculation of wind speed. However the biggest subject concern algorithms for mean radiant temperature (Mrt) calculations, different models and programs which simplify calculations of this complex index though introduce different approximations and, as a result, many false results. The paper presents also wide range of UTCI applications in urban bioclimate studies and bioclimatic mapping, climate-human health researches and biometeorological forecasts which were the primary purpose of the index creation, but also applications in tourism and recreation or even in bioclimate change analysis.
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Gatto, Elisa, Riccardo Buccolieri, Eeva Aarrevaara, Fabio Ippolito, Rohinton Emmanuel, Leonardo Perronace, and Jose Luis Santiago. "Impact of Urban Vegetation on Outdoor Thermal Comfort: Comparison between a Mediterranean City (Lecce, Italy) and a Northern European City (Lahti, Finland)." Forests 11, no. 2 (February 18, 2020): 228. http://dx.doi.org/10.3390/f11020228.
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This paper is devoted to the application of the modelling approach, as one of the methods for the evaluation of thermal comfort, to neighborhoods located in two cities characterized by a different climate, i.e., a Mediterranean city in southern Italy (Lecce) and a northern European city in southern Finland (Lahti). The impact of the presence of vegetation in both places is evaluated and compared, further considering alternative scenarios for thermal comfort improvement. The thermal comfort condition is expressed in terms of indices (mean radiant temperature (MRT) and predicted mean vote (PMV)). Results show that at pedestrian level the presence of vegetation lead to an improvement of thermal comfort in summer of about 2 points in both neighborhoods. This improvement is also evident observing the spatial distribution of MRT with a difference of 7 °C in the Lecce neighborhood and 3 °C in Lahti. In winter, thermal discomfort is observed in the presence of vegetation with a difference of 1.3 °C in the Lecce neighborhood and 1.5 °C in Lahti in terms of MRT. However, trees and green cover have the important potential to offset climate change impact and to make urban environments less thermally stressful. This study aims to guide urban planners towards a motivated and necessary transaction towards new green infrastructure whose effect should, however, be analyzed and investigated case by case.
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Lou, Robert, Kevin P. Hallinan, Kefan Huang, and Timothy Reissman. "Smart Wifi Thermostat-Enabled Thermal Comfort Control in Residences." Sustainability 12, no. 5 (March 3, 2020): 1919. http://dx.doi.org/10.3390/su12051919.
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The present research leverages prior works to automatically estimate wall and ceiling R-values using a combination of a smart WiFi thermostat, building geometry, and historical energy consumption data to improve the calculation of the mean radiant temperature (MRT), which is integral to the determination of thermal comfort in buildings. To assess the potential of this approach for realizing energy savings in any residence, machine learning predictive models of indoor temperature and humidity, based upon a nonlinear autoregressive exogenous model (NARX), were developed. The developed models were used to calculate the temperature and humidity set-points needed to achieve minimum thermal comfort at all times. The initial results showed cooling energy savings in excess of 83% and 95%, respectively, for high- and low-efficiency residences. The significance of this research is that thermal comfort control can be employed to realize significant heating, ventilation, and air conditioning (HVAC) savings using readily available data and systems.
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D E V S, Kiran Kumar, Man Pun Wan, Mandi Zhou, Yongping Long, and Bing Feng Ng. "Impact of solar reflectance of wall and road on outdoor thermal comfort - experimental study in a street canyon setup." MATEC Web of Conferences 282 (2019): 02010. http://dx.doi.org/10.1051/matecconf/201928202010.
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Thermal environment in an urban street canyon is primarily affected by prevailing air conditions, wind flow, solar radiation as well as thermal properties of the surrounding urban structures and pavement surfaces that affect the reflection, absorption and re-emission of solar radiation. Experiments were conducted in a 1:5 scale test setup consisting of North-South oriented street canyon (height to width ratio 1.7) located in Singapore. Test cases covering two levels solar reflectance of walls (0.35 and 0.57) and road (0.12 and 0.55) were conducted in a three-month period. Environmental parameters including direct beam and diffuse solar radiation, net radiation (incoming and outgoing shortwave and longwave radiation) and wind speed were continuously measured at the top of the canyon. Thermal comfort parameters including air temperature, relative humidity, air velocity and globe temperature were also monitored continuously inside the street canyon. When the solar reflectance of canyon surfaces increases, mean radiant temperature (MRT) reduces by up to 1.2°C during daytime and 2.5°C during the night. Such reduction leads to reduced occurrence of heat stress by 34% and 42% during the day and night times, respectively, as measured by the universal thermal comfort index (UTCI). This paper further discusses the effect of longwave radiation on MRT in the street canyon due to changes in canyon solar reflectance.
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Zhao, Xuexiu, Yanwen Luo, and Jiang He. "Analysis of the Thermal Environment in Pedestrian Space Using 3D Thermal Imaging." Energies 13, no. 14 (July 16, 2020): 3674. http://dx.doi.org/10.3390/en13143674.
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Pedestrian space is an important place for people’s outdoor activities. Its thermal environment affects pedestrian walking experience, route selection and physical health. This study presents a 3D thermography-based method to analyze and evaluate the spatial distribution of thermal comfort. The proposed 3D thermal image was generated using 3D city models captured by an unmanned aerial vehicle (UAV) and thermal images gathered by an infrared camera. It can visualize construction elements, but also simply output surface temperatures at selected points. This paper described the process of using 3D thermal images to analyze the built environment, and selected two pedestrian spaces as case study objects. Their thermal images and mean radiant temperatures (MRT) were obtained from field measurement data collected by a drone and infrared camera. The following findings were obtained: (a) the MRT difference in the pedestrian space between sunlit and shaded areas was more than 3 °C; (b) the MRT values at the measurement points near vegetation were lower; (c) when the ratio of street height to width (H/W) was larger, the MRT values at all measurement points varied slightly. These findings can be used for the designers to evaluate and improve the thermal environment in pedestrian space.
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Kalmár, Ferenc, and Tünde Kalmar. "Impact of Building Refurbishment on the Operative Temperature and PMV." Advanced Materials Research 1041 (October 2014): 325–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1041.325.
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Energy saving is one of the main priorities in the building sector. In the last years in Hungary different national programs were launched in order to improve the thermal properties of residential buildings. In case of building refurbishment 40-60% heating energy savings were expected. There were cases when the expected energy savings have not been met. The aim of this research was to see which the refurbishment impact is on the thermal comfort in a residential building. It was found the mean radiant temperature, the operative temperature and the predicted mean vote (PMV) decrease after building refurbishment.
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Gatto, Elisa, Fabio Ippolito, Gennaro Rispoli, Oliver Savio Carlo, Jose Luis Santiago, Eeva Aarrevaara, Rohinton Emmanuel, and Riccardo Buccolieri. "Analysis of Urban Greening Scenarios for Improving Outdoor Thermal Comfort in Neighbourhoods of Lecce (Southern Italy)." Climate 9, no. 7 (July 12, 2021): 116. http://dx.doi.org/10.3390/cli9070116.
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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.
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Takebayashi, Hideki. "Thermal Environment Design of Outdoor Spaces by Examining Redevelopment Buildings Opposite Central Osaka Station." Climate 7, no. 12 (December 14, 2019): 143. http://dx.doi.org/10.3390/cli7120143.
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Thermal environmental design in an outdoor space is discussed by focusing on the proper selection and arrangement of buildings, trees, and covering materials via the examination of redevelopment buildings in front of Central Osaka Station, where several heat island countermeasure technologies have been introduced. Surface temperatures on the ground and wall were calculated based on the surface heat budget equation in each 2 m size mesh of the ground and building wall surface. Incident solar radiation was calculated using ArcGIS and building shape data. Mean radiant temperature (MRT) of the human body was calculated using these results. Distribution of wind velocity was calculated by computational fluid dynamics (CFD) reproducing buildings, obstacles, trees, and the surroundings. The effect of MRT on SET* was greater than that of wind velocity at 13:00 and 17:00 on a typical summer day. SET* reduction was the highest by solar radiation shading, followed by surface material change and ventilation. The largest ratio of the area considered for the thermal environment was 83% on Green Garden, which consists of 44% of building shade, 21% of tree shade, 7% of water surface, and 11% of green cover. It is appropriate to consider the thermal environment design of outdoor space in the order of shade by buildings, shading by trees, and improvement of surface materials.
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Kwon, You Jin, and Dong Kun Lee. "Thermal Comfort and Longwave Radiation over Time in Urban Residential Complexes." Sustainability 11, no. 8 (April 15, 2019): 2251. http://dx.doi.org/10.3390/su11082251.
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Large cities with a high concentration of high-rise buildings are shaded by urban canyon. This brings a cooling effect compared to the space exposed to the sun, but is not always cool due to the longwave radiation emitted from buildings and the built environment. We tested the micro-scale effects of major external spatial factors, trees, and buildings, under shade on longwave radiation shifts to understand the effects of large shaded areas in megacities. Incoming and outgoing longwave radiations (ILR and OLR, respectively) were found to decrease the overall observation by time zone. Longwave radiation on a micro-scale was also inversely proportional to the tree volume. From mean radiant temperature (MRT) analysis, we found that about a 10% decrease in MRT could be achieved by increasing tree volume by around 50%. Larger tree volumes corresponded to greater blocking effects on longwave radiation. Considering the tree volume, a multilayer urban tree canopy composition can more favorably improve the thermal environment and energy sustainability of a city compared to a single-layer canopy. Larger trees planted with harmonious shrubs are the most effective in reducing longwave radiation.
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Binarti, F., MD Koerniawan, S. Triyadi, and SS Utami. "Maximizing the ENVI-met Capability of Modelling the Mean Radiant Temperature of a Tropical Archaeological Site." IOP Conference Series: Earth and Environmental Science 541 (July 28, 2020): 012005. http://dx.doi.org/10.1088/1755-1315/541/1/012005.
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Zhou, Zeng, Qinli Deng, Guang Yang, and Yaolin Lin. "Quantitative Study of Using Piloti for Passive Climate Adaptability in a Hot-Summer and Cold-Winter City in China." International Journal of Environmental Research and Public Health 15, no. 10 (October 9, 2018): 2202. http://dx.doi.org/10.3390/ijerph15102202.
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There has been an insufficient study of passive climate adaptability that considers both the summer and winter season for the outdoor thermal environment of hot-summer and cold-winter cities. In this study, we performed a quantitative simulation to research the passive climate adaptability of a residential area, considering piloti as the main method for climate adaptation in a hot-summer and cold-winter city in China. Numerical simulations were performed with a coupled simulation method of convection, radiation, and conduction. A cubic non-linear k–ε model proposed by Craft et al. was selected as the turbulence model and three-dimensional multi-reflections of shortwave and longwave radiations were considered in the radiation simulation. Through the simulation, we found that setting the piloti at the two ends of the building was the optimal piloti arrangement for climate adaptation. Then the relationship between the piloti ratio (0%, 20%, 40%, 60%, and 80%) and the outdoor thermal environment was studied. It could be concluded that with the increasing piloti ratio, the wind velocity increased, the mean radiant temperature (MRT) decreased slightly, and the average standard effective temperature (SET*) decreased to 3.6 °C in summer, while in winter, with the increasing piloti ratio, the wind velocity, MRT, and SET* changed slightly. The wind environment significantly affected the SET* value, and the piloti ratio should be between 12% and 38% to avoid wind-induced discomfort.
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Loibl, Wolfgang, Milena Vuckovic, Ghazal Etminan, Matthias Ratheiser, Simon Tschannett, and Doris Österreicher. "Effects of Densification on Urban Microclimate—A Case Study for the City of Vienna." Atmosphere 12, no. 4 (April 17, 2021): 511. http://dx.doi.org/10.3390/atmos12040511.
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Climate adaptation, mitigation, and protecting strategies are becoming even more important as climate change is intensifying. The impacts of climate change are especially tangible in dense urban areas due to the inherent characteristics of urban structure and materiality. To assess impacts of densification on urban climate and potential adaptation strategies a densely populated Viennese district was modeled as a typical sample area for the city of Vienna. The case study analyzed the large-scale densification potential and its potential effects on microclimate, air flow, comfort, and energy demand by developing 3D models of the area showing the base case and densification scenarios. Three methods were deployed to assess the impact of urban densification: Micro-climate analysis (1) explored urban heat island phenomena, wind pattern analysis (2) investigated ventilation and wind comfort at street level, and energy and indoor climate comfort analysis (3) compared construction types and greening scenarios and analyzed their impact on the energy demand and indoor temperatures. Densification has negative impacts on urban microclimates because of reducing wind speeds and thus weakening ventilation of street canyons, as well as accelerating heat island effects and associated impact on the buildings. However, densification also has daytime cooling effects because of larger shaded areas. On buildings, densification may have negative effects especially in the new upper, sun-exposed floors. Construction material has less impact than glazing area and rooftop greening. Regarding adaptation to climate change, the impacts of street greening, green facades, and green roofs were simulated: The 24-h average mean radiant temperature (MRT) at street level can be reduced by up to 15 K during daytime. At night there is only a slight reduction by a few tenths of 1 K MRT. Green facades have a similar effect on MRT reduction, while green roofs show only a slight reduction by a few tenths of 1 K MRT on street level. The results show that if appropriate measures were applied, negative effects of densification could be reduced, and positive effects could be achieved.
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Akinbobola, A., and T. Fafure. "Assessing the Impact of Urbanization on Outdoor Thermal Comfort in Selected Local Government Areas in Ogun State, Nigeria." March 2021 5, no. 1 (March 2021): 120–39. http://dx.doi.org/10.36263/nijest.2021.01.0243.
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This study seeks to assess the land use land cover (LULC) and spatial-temporal trends of six outdoor thermal comfort indices in four Local Government Areas (LGAs) of Ogun state, Southwestern, Nigeria. Data used for this study are air temperature, relative humidity, cloud cover and wind speed which span from 1982 to 2018. These data were obtained from ERA-INTERIM archive. The 1986, 2000 and 2018 used for the analysis of the LULC were from the satellite imagery hosted by the United States Geological Survey (USGS). Landsat Thematic Mapper, Landsat 7 and Landsat 8 Operational Land Imager data of 1986, 2000 and 2018 to assess the changes that have taken place between these periods. Thermal comfort indices such as Effective Temperature (ET), Temperature Humidity Index (THI), Mean radiant temperature (MRT) and Relative Strain Index (RSI) were used. Rayman model was used for the computation of the three thermal comfort indices (MRT, PET, PMV). The results show decrease in vegetation, forest, and an increase in percentage of built-up areas between 1986–2000, and 2000–2018. A rapid increase in built-up areas in the three (Abeokuta South, Ifo, Shagamu,) of the four LGAs, while one (Ijebu East) has a slow increase in the built-up areas. The trend in the thermal comfort indices also shows that thermal discomfort had been on increase for the past 37 years and it was observed that the level of comfort has deteriorated more in the last decade compared to the previous decade especially in the built-up areas. This work suggests a framework for evaluating the relationship between the quantitative and qualitative parameters linking the microclimatic environment with subjective thermal assessment. This will contribute to the development of thermal comfort standards for outdoor urban settings. Also, the study will help urban planners in their decision making, and in heat forecast.
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Hamzah, Baharuddin, Muhammad Taufik Ishak, Syarif Beddu, and Mohammad Yoenus Osman. "Thermal comfort analyses of naturally ventilated university classrooms." Structural Survey 34, no. 4/5 (August 8, 2016): 427–45. http://dx.doi.org/10.1108/ss-12-2015-0055.
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Purpose The purpose of this paper is to analyse thermal comfort and the thermal environment in naturally ventilated classrooms. Specifically, the aims of the study were to identify the thermal environment and thermal comfort of respondents in naturally ventilated university classrooms and compare them with the ASHRAE and Indonesian National Standard (SNI); to check on whether the predicted mean vote (PMV) model is applicable or not for predicting the thermal comfort of occupants in naturally ventilated university classrooms; and to analyse the neutral temperature of occupants in the naturally ventilated university classrooms. Design/methodology/approach The study was carried out at the new campus of Faculty of Engineering, Hasanuddin University, Gowa campus. A number of field surveys, which measured thermal environments, namely, air temperature, mean radiant temperature (MRT), relative humidity, and air velocity, were carried out. The personal activity and clothing properties were also recorded. At the same time, respondents were asked to fill a questionnaire to obtain their thermal sensation votes (TSV) and thermal comfort votes (TCV), thermal preference, and thermal acceptance. A total of 118 respondents participated in the study. Before the survey was conducted, a brief explanation was provided to the participants to ensure that they understood the study objectives and also how to fill in the questionnaires. Findings The results indicated that the surveyed classrooms had higher thermal environments than those specified in the well-known ASHRAE standard and Indonesian National Standard (SNI). However, this condition did not make respondents feel uncomfortable because a large proportion of respondents voted within the comfort zone (+1, 0, and −1). The predictive mean vote using the PMV model was higher than the respondents’ votes either by TSV or by TCV. There was a huge difference between neutral temperature using operative temperature (To) and air temperature (Ta). This difference may have been because of the small value of MRT recorded in the measured classrooms. Originality/value The research shows that the use of the PMV model in predicting thermal comfort in the tropic region might be misleading. This is because PMV mostly overestimates the TSV and TCV of the respondents. People in the tropic region are more tolerant to a higher temperature. On the basis of this finding, there is a need to develop a new thermal comfort model for university classrooms that is particularly optimal for this tropical area.
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De, Bhaskar, and Mahua Mukherjee. "Optimizing Street Canyon Orientation for Rajarhat Newtown, Kolkata, India." Environmental and Climate Technologies 21, no. 1 (December 1, 2017): 5–17. http://dx.doi.org/10.1515/rtuect-2017-0012.
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Abstract Air temperature in urban street canyons is increased due to the morphed urban geometry, increased surface area, decreased long wave radiation and evapo-transpiration, different thermo-physical properties of surface materials and anthropogenic heat which results in thermal discomfort. Outdoor thermal stress can be mitigated substantially by properly orienting the canyons. It is crucial for the urban planners and designers to orient street canyons optimally considering variable local climatic context. It is important especially for cities in warm humid climatic context as these cities receive higher insolation with higher relative humidity and low level macro wind flow. This paper examines influence of canyon orientation on outdoor thermal comfort and proposes the optimum canyon orientation for the Rajarhat Newtown, Kolkata – a city in warm humid climate zone. Different scenarios are generated with different orientations. Change in air temperature, wind speed, Mean Radiant Temperature (MRT) and Physiological Equivalent Temperature (PET) of different scenarios are compared to find out the optimum orientation by parametric simulation in ENVI_met. Analysing the simulation results it is observed that orientation angle between 30°–60° to north performs the best for the study area of the Rajarhat Newtown. The findings of this research will be helpful for the planners to orient the street canyons optimally for future development and extension of the Rajarhat Newtown, Kolkata.
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Zulfiana, Indah Sari. "Kenyamanan Termal Adaptif Rumah Tinggal di Kota Timika Papua." JTT (Jurnal Teknologi Terpadu) 7, no. 2 (October 30, 2019): 130–34. http://dx.doi.org/10.32487/jtt.v7i2.750.
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Indonesia merupakan negara beriklim tropis dengan temperatur dan kelembaban yang tinggi di beberapa kota termasuk di Timika. Hal ini menyebabkan kondisi termal yang tidak nyaman serta penggunaan standar kenyamanan ruang yang ada sering berbeda dengan persepsi penghuni sehingga mengakibatkan pemborosan energi pendingin ruang.Penelitian ini bertujuan: (1) mengetahui kenyamanan termal adaptif pada penghuni rumah tinggal sederhana berventilasi alami di kota Timika, yakni kenetralan, keberterimaan dan preferensi termal penghuni, dan (2) mengetahui perilaku adaptif penghuni dalam pencapaian kenyamanan termal individu. Penelitian ini dilaksanakan di salah satu rumah tinggal berventilasi alami pada salah satu perumahan di daerah urban dan suburban di kota Timika. Digunakan pengukuran empat parameter lingkungan, yakni suhu, kelembaban, kecepatan udara, dan mean radiant temperature (MRT).Data diperoleh melalui pengisian kuesioner kepada seratus responden di daerah urban dan suburban.Data kenetralan termal dianalisis dengan analisis regresi menggunakan software SPSS 19, sedangkan keberterimaan dan preferensi termal serta perilaku adaptif dianalisis berdasarkan hasil dari jawaban kuesioner. Hasil penelitian menunjukkan bahwa kenetralan termal yang tinggi, yaitu 30.560C Top pada daerah urban dan 30.170C Toppada daerah suburban. Lebih dari 90% responden dapat menerima kondisi termal setempat.Akan tetapi, lebih dari 50% menginginkan kondisi termal menjadi lebih sejuk.Perilaku yang paling sering dilakukan responden dalam mencapai kenyamanan termal individu, yakni menyalakan kipas angin.
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Mutani, Guglielmina, and Valeria Todeschi. "Roof-Integrated Green Technologies, Energy Saving and Outdoor Thermal Comfort: Insights from a Case Study in Urban Environment." International Journal of Sustainable Development and Planning 16, no. 1 (February 28, 2021): 13–23. http://dx.doi.org/10.18280/ijsdp.160102.
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Green urban infrastructures have a significant impact on urban climate mitigation, on indoor and outdoor thermal comfort and on energy performance of buildings. In this paper, outdoor thermal comfort conditions and energy saving for space heating and cooling were investigated before and after the use of roof-integrated green technologies. Existing urban energy and climate models and tools were applied to an urban area located in a Turin (Italy). CitySim, ENVI-met and SOLWEIG tools and a GIS-based model were used to evaluate the mean radiant temperature and the thermal comfort of outdoor spaces before and after the use of vegetated roofs and green surfaces such as the predicted mean vote (PMV), the physiological equivalent temperature (PET) and the universal thermal climate index (UTCI). A GIS-based engineering model and CitySim tool were used to evaluate the energy saving and energy independence index for space heating and cooling after the use of green roofs and solar technologies. According to the shape and the suitability of rooftop elaborated with GIS tools, some roofs were identified as potential green roofs other as potential solar roofs for installing solar thermal collectors and photovoltaic panels. According to the results it is possible to confirm that the use of green roofs and urban greenery can decrease the mean radiant temperature until about 10℃ during summer season, improving outdoor thermal comfort conditions and energy savings with a reduction of 12% for space cooling energy consumption.
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Paramita, Beta, and Hiroatsu Fukuda. "Public Housing in Bandung an Assessment and Approaches through Urban Physics." Advanced Materials Research 935 (May 2014): 273–76. http://dx.doi.org/10.4028/www.scientific.net/amr.935.273.
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High density of population and vertical buildings seems to be the only aspect fit to the concept for city in the developing country. The vertical housings then become a matter of necessity in high density area, in which the building groups themselves significantly contribute to microclimate at urban scales. This study is going to give descriptions of outdoor thermal comfort of public housing in Bandung by means its correlation between urban forms and mean radiant temperature. A number of simulations have used ENVI-met to reveal a better urban form which addresses the role of urban physics in the study of outdoor thermal comfort in a hot humid climate area.
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Égerházi, L. A., N. Kántor, and T. Gál. "Evaluation and modelling the micro-bioclimatological conditions of a popular playground in Szeged, Hungary." International Review of Applied Sciences and Engineering 4, no. 1 (June 1, 2013): 57–61. http://dx.doi.org/10.1556/irase.4.2013.1.8.
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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.
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Yang, Xiao Bin, Zhi Long Chen, and Hao Cai. "The Research on the Impact of the Underground Parking to the Microclimate in Residential Quarter." Advanced Materials Research 869-870 (December 2013): 178–84. http://dx.doi.org/10.4028/www.scientific.net/amr.869-870.178.
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Currently, more and more residential district have built the underground parking and created more water and green space use the ground. The environment has been improved. This paper analyzed the microclimate of two planning programs use the microclimate fluid dynamics simulation software Envi-met, that one is have been made the underground parking planning, the other one is haven't. The results include microclimate parameters air quality parameters (the distribution of CO2) and the outdoor thermal comfort parameters (mean radiant temperature). By comparing the results of the two programs, this paper quantitative analyzed the influence and benefits of the underground parking to the microclimate in residential quarter.
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Zulfiana, Indah Sari. "KENYAMANAN TERMAL ADAPTIF MAHASISWA DI UNIVERSITAS SAINS DAN TEKNOLOGI JAYAPURA." JTT (Jurnal Teknologi Terpadu) 9, no. 1 (April 28, 2021): 17–23. http://dx.doi.org/10.32487/jtt.v9i1.952.
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To get good quality learning, a comfortable study room is needed both visually, audally and thermally. Thermal comfort is greatly influenced by the climatic conditions of a region. In areas with high daily air temperature, high humidity and low air velocity, it is difficult to produce thermal comfort with natural air conditioning. Jayapura City is one of the cities in Indonesia with daily air temperature and high humidity and low air velocity. Therefore, adaptive processes are needed to achieve thermal comfort in spaces, including study rooms. Each human's adaptive thermal comfort is different according to local climatic conditions. The purpose of this study was to determine the adaptive thermal comfort of students in naturally ventilated classrooms at the Jayapura University of Science and Technology (USTJ) in the city of Jayapura, Papua, namely students 'neutrality, acceptance and thermal preferences, as well as students' adaptive behavior in achieving thermal comfort. This research was conducted in one of USTJ's classrooms in Jayapura, Papua. Four environmental parameters were measured, namely temperature, humidity, wind speed, and mean radiant temperature (MRT). The data were obtained through filling out a questionnaire to 100 USTJ students during the space measurement. Thermal neutrality data were analyzed using regression analysis using SPSS software, while thermal acceptance and preference and adaptive behavior were analyzed based on the results of the questionnaire answers. The results showed that USTJ students' thermal neutrality was at 29.°C Ta or 29.55°C Top. all students can accept the thermal conditions of the room, but 59% of students choose to want the room to be cooler due to their thermal preferences. The adaptive behavior that is carried out is turning on the fan, picking up objects to be used as a fan, leaving the room and drinking more often.
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Spangenberg, Jörg, Paula Shinzato, Erik Johansson, and Denise Duarte. "SIMULATION OF THE INFLUENCE OF VEGETATION ON MICROCLIMATE AND THERMAL COMFORT IN THE CITY OF SÃO PAULO." Revista da Sociedade Brasileira de Arborização Urbana 3, no. 2 (April 30, 2019): 1. http://dx.doi.org/10.5380/revsbau.v3i2.66265.
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The microclimates of a park, a square and a street canyon were measured on a summer day in the city centre of São Paulo, Brazil. The field monitoring showed that the park was up to 2°C cooler than the square and the canyon. The effect of adding shading trees to the street canyon was simulated for the same day using the numerical model ENVI-met. The simulations showed that incorporating street trees in the urban canyon had a limited cooling effect on the air temperature (up to 1.1°C), but led to a significant cooling of the street surface (up to 12°C) as well as a great reduction of the mean radiant temperature at pedestrian height (up to 24°C). Although the trees lowered the wind speed up to 45% of the maximum values, the thermal comfort was improved considerably as the physiologically equivalent temperature (PET) was reduced by up to 12°C.
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Mohammed, Younis, and Aws Salman. "Effect of urban geometry and green area on the formation of the urban heat island in Baghdad city." MATEC Web of Conferences 162 (2018): 05025. http://dx.doi.org/10.1051/matecconf/201816205025.
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With the growth of cities, the ambient air temperatures (Ta) inside the urban areas are expected to be higher compared to the surrounding rural areas, creating urban heat island (UHI) phenomenon. The city of Baghdad is an example of a hot dry climate cities and during summer, the UHI intensity is significantly affected by the extreme direct solar radiation and leads to outdoor thermal discomfort. Also it causes an increase in energy consumption and air pollution. This research work focuses on the effect of urban geometry and green area in the formation of heat island through a study of two different fabrics of residential neighbourhoods. The height to width ratio (H/W) and vegetation are adopted while the materials of buildings were unified in all study cases. Three-dimensional numerical software Envi-met 4.1 was utilized to analyze and assess the studied parameters including: ambient air temperature (Ta), street surface temperature (Ts) and mean radiant temperature (Tmrt). This study has given a better understanding of the role of urban geometry and green area on forming the UHI that influence on the microclimatic conditions in hot dry climate of the city of Baghdad. So that helped to generate guidelines of urban design and planning practices for a better thermal performance in hot and dry cities.
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Qodir, Abdul, Erni Setyowati, and Suryono Suryono. "ANALISIS PENGARUH BENTUK SERAMBI MASJID TERHADAP KENYAMANAN TERMAL ADAPTIF." Jurnal Arsitektur ARCADE 4, no. 3 (November 19, 2020): 261. http://dx.doi.org/10.31848/arcade.v4i3.522.
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This study examines the effect of the porch on the adaptive thermal comfort of mosques by taking 2 mosques that have different porch shapes with the specific purpose of obtaining data on the neutrality, acceptability and preferences of the mosque respondents' thermal conditions in the framework of developing adaptive thermal comfort standards for Indonesia. Measurement of physical environment variables is done by taking data on temperature, humidity, air velocity, and mean radiant temperature (MRT) at 2 mosques and at the same time the impression and thermal preference questionnaire data are taken, examination of clothing types and activities, and list of thermal environment controls to 40 respondents in each mosque. Data of thermal neutrality and thermal preferences were analyzed by regression analysis using SPSS 19 software, while thermal acceptance was analyzed based on the results of the questionnaire answers. The analysis showed that the neutrality value at Ulul Albab mosque was Tdb = 28.47 OC, ET * = 30.11 OC, SET * = 23.11 OC, TSENS = 1.17, DISC = -1.06, and PMV = -0.65, this data shows that the neutral condition desired by respondents is slightly below the average condition, while the neutrality in Nurul Ilmi mosque at Tdb = 30.27 OC, ET * = 31.65 OC, SET * = 29.05 OC, TSENS = 1.03, DISC = 1.68, and PMV = 1.22, this data also shows that the neutral conditions desired by respondents are slightly below average conditions. While the preference value at Ulul Albab mosque is Tdb = 22.25 OC, ET * = 28.62 OC, SET * = 24.24 OC, TSENS = 0.23, DISC = 0.23, and PMV = -0.60 and preference conditions at Nurul Ilmi mosque at Tdb = 29.11 OC, ET * = 31.17 OC, SET * = 28.50 OC, TSENS = 1.04, DISC = 1.45, and PMV = 1.03. As many as 92% of respondents in the Ulul Albab mosque can accept local thermal conditions in the temperature range of 27oC - 31oC. While 90% of respondents in the Nurul Ilmi mosque can accept local thermal conditions in the temperature range of 27oC-32oC. The results of the neutrality, acceptance and preference analysis show that the Ulul Albab mosque is better than the Nurul Ilmi mosque.
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Bande, Lindita, Afshin Afshari, Dina Al Masri, Mukesh Jha, Leslie Norford, Alexandros Tsoupos, Prashanth Marpu, Yosha Pasha, and Peter Armstrong. "Validation of UWG and ENVI-Met Models in an Abu Dhabi District, Based on Site Measurements." Sustainability 11, no. 16 (August 13, 2019): 4378. http://dx.doi.org/10.3390/su11164378.
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The city of Abu Dhabi is growing every year in population, urban extent and energy demand. This research focuses on the application of two simulation programs to estimate changes in urban climate associated with continued development in Abu Dhabi: The Urban Weather Generator (UWG) and ENVI-met. Simulation with these two software packages are validated with the site data measured in downtown Abu Dhabi. A comparison analysis (in the different seasons) between the rural data, the simulation output, and the site measurements shows the variations of the UHI in this Middle Eastern city and the potential of the validated tools. The main aims of this study are: (a) to make a seasonal validation of the UWG for the city of Abu Dhabi (referring to urban-rural available data). The tool was previously validated for a year (no seasonal division) for Abu Dhabi, Toulouse, Basel, Singapore, Rome and Barcelona. The simulations are based on the 2016 version of the Urban Weather Generator. The analysis is separated into three main seasons (instead of the full year): winter, spring, summer. (b) To make a seasonal validation and improve the second tool evaluated in this study, ENVI-met 4.0. The software can simulate urban temperature, humidity and wind speed. Guides are proposed for the enhancement of the accuracy of both estimation procedures. Referring to the results, UWG tends to overestimate the canyon temperature during the summer and has a more realistic estimation on the winter season. ENVI-met has better estimations of temperatures during the summer season compared to UWG. Finally, the UWG weather file contributes a more detailed energy model on a mesoscale model. It considers the seasonal effect and shows the impact of the climate on profiling the UHI phenomena. ENVI-met needs improvement in calculating the anthropogenic heat and in calculation of the mean radiant temperature.
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Shata, Randa Osama, Ayman Hassaan Mahmoud, and Mohammad Fahmy. "Correlating the Sky View Factor with the Pedestrian Thermal Environment in a Hot Arid University Campus Plaza." Sustainability 13, no. 2 (January 6, 2021): 468. http://dx.doi.org/10.3390/su13020468.
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In hot, arid regions on university campuses, students are more vulnerable to heat stresses than in street canyons in terms of function; however, the knowledge of the impact of built environments on thermal performance is still lacking. In two summer and winter days, the shading effect of the existing urban trees pattern in a university campus in Egypt was examined to correlate their Sky View Factor (SVF) with the thermal environment, meteorology, Physiological Equivalent Temperature (PET), and Universal Thermal Comfort Index (UTCI). The ENVI-met model was used in order to assess meteorological parameters, followed by SVF calculation in the Rayman program. Meteorological field measurements validated the simulation model and measured the Leaf Area Index (LAI) of two native urban trees to model the in-situ canopies foliage. In summer, the results showed a significant direct impact of the SVF on mean radiant temperature (Tmrt), PET, and UTCI; however, the excessive shading by trees on materials with a low albedo and low wind speed could lead to a slight increase in air temperature. Meanwhile, in the winter, SVF did not affect the microclimatic variables, PET, or UTCI. The resulting insight into the correlation between SVF and Tmrt emphasizes the importance of urban trees in modifying the microclimates of already-existing university plazas.
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Jänicke, Britta, Fred Meier, Marie-Therese Hoelscher, and Dieter Scherer. "Evaluating the Effects of Façade Greening on Human Bioclimate in a Complex Urban Environment." Advances in Meteorology 2015 (2015): 1–15. http://dx.doi.org/10.1155/2015/747259.
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The evaluation of the effectiveness of countermeasures for a reduction of urban heat stress, such as façade greening, is challenging due to lacking transferability of results from one location to another. Furthermore, complex variables such as the mean radiant temperature(Tmrt)are necessary to assess outdoor human bioclimate. We observedTmrtin front of a building façade in Berlin, Germany, which is half-greened while the other part is bare.Tmrtwas reduced (mean 2 K) in front of the greened compared to the bare façade. To overcome observational shortcomings, we applied the microscale models ENVI-met, RayMan, and SOLWEIG. We evaluated these models based on observations. Our results show thatTmrt(MD = −1.93 K) and downward short-wave radiation (MD = 14.39 W/m2) were sufficiently simulated in contrast to upward short-wave and long-wave radiation. Finally, we compare the simulated reduction ofTmrtwith the observed one in front of the façade greening, showing that the models were not able to simulate the effects of façade greening with the applied settings. Our results reveal that façade greening contributes only slightly to a reduction of heat stress in front of building façades.
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Palladino, Domenico, Iole Nardi, and Cinzia Buratti. "Artificial Neural Network for the Thermal Comfort Index Prediction: Development of a New Simplified Algorithm." Energies 13, no. 17 (September 1, 2020): 4500. http://dx.doi.org/10.3390/en13174500.
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A simplified algorithm using an artificial neural network (ANN, a feed-forward neural network) for the assessment of the predicted mean vote (PMV) index in summertime was developed, using solely three input variables (namely the indoor air temperature, relative humidity, and clothing insulation), whilst low air speed (<0.1 m/s), a minimal variation of radiant temperature (25.1 °C ± 2 °C) and steady metabolism (1.2 Met) were considered. Sensitivity analysis to the number of variables and to the number of neurons were performed. The developed ANN was then compared with three proven methods used for thermal comfort prediction: (i) the International Standard; (ii) the Rohles model; (iii) the modified Rohles model. Finally, another network able to predict the indoor thermal conditions was considered: the combined calculation of the two networks was tested for the PMV prediction. The proposed algorithm allows one to better approximate the PMV index than the other models (mean error of ANN predominantly in ±0.10–±0.20 range). The accuracy of the network in PMV prediction increases when air temperature and relative humidity values fall into 21–28 °C and 30–75% ranges. When the PMV is predicted by using the combined calculation (i.e., by using the two networks), the same order of magnitude of error was found, confirming the reliability of the networks. The developed ANN could be considered as an alternative method for the simplified prediction of PMV; moreover, the new simplified algorithm can be useful in buildings’ design phase, i.e., in those cases where experimental data are not available.
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Kántor, Noémi, Csilla Viktória Gál, Ágnes Gulyás, and János Unger. "The Impact of Façade Orientation and Woody Vegetation on Summertime Heat Stress Patterns in a Central European Square: Comparison of Radiation Measurements and Simulations." Advances in Meteorology 2018 (2018): 1–15. http://dx.doi.org/10.1155/2018/2650642.
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Increasing summertime air temperature deteriorates human health especially in cities where the warming tendency is exacerbated by urban heat island. Human-biometeorological studies shed light on the primary role of radiation conditions in the development of summertime heat stress. However, only a limited number of field investigations have been conducted up to now. Based on a 26-hour long complex radiation measurement, this study presents the evolved differences within a medium-sized rectangular square in Szeged, Hungary. Besides assessing the impact of woody vegetation and façade orientation on the radiation heat load, different modeling software programs (ENVI-met, SOLWEIG, and RayMan) are evaluated in reproducing mean radiant temperature (Tmrt). Although daytimeTmrtcan reach an extreme level at exposed locations (65–75°C), mature shade trees can reduce it to 30–35°C. Nevertheless, shading from buildings adjacent to sidewalks plays also an important role in mitigating pedestrian heat stress. Sidewalks facing SE, S, and SW do not benefit from the shading effect of buildings; therefore, shading them by trees or artificial shading devices is of high importance. The measurement–model comparison revealed smaller or larger discrepancies that raise awareness of the careful adaptation of any modeling software and of the relevance of fine-resolution field measurements.
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Paramita, Beta, Hiroatsu Fukuda, Rendy Perdana Khidmat, and Andreas Matzarakis. "Building Configuration of Low-Cost Apartments in Bandung—Its Contribution to the Microclimate and Outdoor Thermal Comfort." Buildings 8, no. 9 (September 4, 2018): 123. http://dx.doi.org/10.3390/buildings8090123.
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This paper aims to find the microclimate aspect within the building form and configuration of five low-cost apartments (henceforth rusun) in Bandung, Indonesia. There are parallel, square, and interspersed plots investigated with specific discussion on the microclimate aspects that gain human perception of outdoor thermal comfort. The microclimate prognostic model, i.e., ENVI-met, was used to determine the mean radiant temperature (Tmrt), which was then used to describe the living quality of outdoor thermal comfort, i.e., PET (physiologically equivalent temperature) in a hot-humid climate context. A parallel plot with building orientation toward north-south was found as the most beneficial building form and configuration. Somehow, the parallel plot toward the west-east orientation did not provide similar performance. Nevertheless, the square plot provided uncomfortable perception as there was an absence of building shade within the wide open space and ground cover to absorb the insolation. The interspersed plot can be considered for the building configuration because it generates more wind among other plots. The building form and configuration of rusun with passive design seems to not be able to achieve outdoor thermal comfort. The highest PET value of Model D with the square plot had PET = 41 °C (hot) while the lowest PET in Model A with the parallel plot (N-S) had PET = 34.2 °C (slightly warm).
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Jiang, L., W. Zhan, and Z. Zou. "TWO METHODS FOR REMOTE ESTIMATION OF COMPLETE URBAN SURFACE TEMPERATURE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W7 (September 12, 2017): 479–87. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w7-479-2017.
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Complete urban surface temperature (<i>T</i><sub>C</sub>) is a key parameter for evaluating the energy exchange between the urban surface and atmosphere. At the present stage, the estimation of <i>T</i><sub>C</sub> still needs detailed 3D structure information of the urban surface, however, it is often difficult to obtain the geometric structure and composition of the corresponding temperature of urban surface, so that there is still lack of concise and efficient method for estimating the <i>T</i><sub>C</sub> by remote sensing. Based on the four typical urban surface scale models, combined with the Envi-met model, thermal radiant directionality forward modeling and kernel model, we analyzed a complete day and night cycle hourly component temperature and radiation temperature in each direction of two seasons of summer and winter, and calculated hemispherical integral temperature and <i>T</i><sub>C</sub>. The conclusion is obtained by examining the relationship of directional radiation temperature, hemispherical integral temperature and <i>T</i><sub>C</sub>: (1) There is an optimal angle of radiation temperature approaching the <i>T</i><sub>C</sub> in a single observation direction when viewing zenith angle is 45&ndash;60°, the viewing azimuth near the vertical surface of the sun main plane, the average absolute difference is about 1.1&thinsp;K in the daytime. (2) There are several (3&ndash;5 times) directional temperatures of different view angle, under the situation of using the thermal radiation directionality kernel model can more accurately calculate the hemispherical integral temperature close to <i>T</i><sub>C</sub>, the mean absolute error is about 1.0&thinsp;K in the daytime. This study proposed simple and effective strategies for estimating <i>T</i><sub>C</sub> by remote sensing, which are expected to improve the quantitative level of remote sensing of urban thermal environment.
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Mola, S., M. Magini, and C. Malvicino. "Equivalent Temperature Estimator Using Mean Radiant Temperature Sensor." Measurement and Control 34, no. 6 (July 2001): 167–69. http://dx.doi.org/10.1177/002029400103400603.
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Air conditioning in transport vehicles is becoming more and more a standard equipment rather than an optional one. Therefore, to assure better comfort conditions in rather non- homogeneous environments like a car cabin becomes a primary task. Since human thermal comfort is the result of the combined effect of several physical quantities, there is the need for new sensors to evaluate real comfort conditions in cars, so to have reliable feedback for a climate control. The present paper describes an equivalent temperature estimator which makes use of a mean radiant temperature sensor. A prototype car has been set up to perform on road and subjective tests.
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Yang, Q., J. D. Fast, H. Wang, R. C. Easter, H. Morrison, Y. N. Lee, E. G. Chapman, S. N. Spak, and M. A. Mena-Carrasco. "Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem." Atmospheric Chemistry and Physics 11, no. 23 (December 2, 2011): 11951–75. http://dx.doi.org/10.5194/acp-11-11951-2011.
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Abstract. This study assesses the ability of the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model to simulate boundary layer structure, aerosols, stratocumulus clouds, and energy fluxes over the Southeast Pacific Ocean. Measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals (i.e., products from the MODerate resolution Imaging Spectroradiometer (MODIS), Clouds and Earth's Radiant Energy System (CERES), and GOES-10) are used for this assessment. The Morrison double-moment microphysics scheme is newly coupled with interactive aerosols in the model. The 31-day (15 October–16 November 2008) WRF-Chem simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations in the microphysics scheme and simplified cloud and aerosol treatments in the radiation scheme. The well-simulated aerosol quantities (aerosol number, mass composition and optical properties), and the inclusion of full aerosol-cloud couplings lead to significant improvements in many features of the simulated stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness. In addition to accounting for the aerosol direct and semi-direct effects, these improvements feed back to the simulation of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengthens the temperature and humidity gradients within the capping inversion layer and lowers the marine boundary layer (MBL) depth by 130 m from that of the MET simulation. These differences are associated with weaker entrainment and stronger mean subsidence at the top of the MBL in AERO. Mean top-of-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity) and aerosol quantities (e.g., underestimations of accumulation mode aerosol number) might affect simulated stratocumulus and energy fluxes over the Southeastern Pacific, and require further investigation. The well-simulated timing and outflow patterns of polluted and clean episodes demonstrate the model's ability to capture daily/synoptic scale variations of aerosol and cloud properties, and suggest that the model is suitable for studying atmospheric processes associated with pollution outflow over the ocean. The overall performance of the regional model in simulating mesoscale clouds and boundary layer properties is encouraging and suggests that reproducing gradients of aerosol and cloud droplet concentrations and coupling cloud-aerosol-radiation processes are important when simulating marine stratocumulus over the Southeast Pacific.
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Davies, M. G. "Mean radiant temperature in the CIBSE Guide." Building Services Engineering Research and Technology 11, no. 2 (May 1990): 69–71. http://dx.doi.org/10.1177/014362449001100205.
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Gan, Guohui. "Analysis of mean radiant temperature and thermal comfort." Building Services Engineering Research and Technology 22, no. 2 (May 2001): 95–101. http://dx.doi.org/10.1191/014362401701524154.
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Kalmár, Ferenc, and Tünde Kalmár. "Interrelation between mean radiant temperature and room geometry." Energy and Buildings 55 (December 2012): 414–21. http://dx.doi.org/10.1016/j.enbuild.2012.08.025.
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Thorsson, Sofia, Joacim Rocklöv, Janina Konarska, Fredrik Lindberg, Björn Holmer, Bénédicte Dousset, and David Rayner. "Mean radiant temperature – A predictor of heat related mortality." Urban Climate 10 (December 2014): 332–45. http://dx.doi.org/10.1016/j.uclim.2014.01.004.
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Du, Jing, Lin Liu, Xin Chen, and Jing Liu. "Field Assessment of Neighboring Building and Tree Shading Effects on the 3D Radiant Environment and Human Thermal Comfort in Summer within Urban Settlements in Northeast China." Advances in Meteorology 2020 (September 23, 2020): 1–19. http://dx.doi.org/10.1155/2020/8843676.
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Shading is one of the most effective strategies to mitigate urban local-scale heat stress during summer. Therefore, this study investigates the effects of shading caused by buildings and trees via exhaustive field measurement research on urban outdoor 3D radiant environment and human thermal comfort. We analyzed the characteristics of micrometeorology and human thermal comfort at shaded areas, and compared the difference between building and tree shading effects as well as that between shaded and sunlit sites. The results demonstrate that mean radiant temperature Tmrt (mean reduction values of 28.1°C for tree shading and 28.8°C for building shading) decreased considerably more than air temperature Ta (mean reduction values of 1.9°C for tree shading and 1.2°C for building shading) owing to shading; furthermore, the reduction effect of shading on UTCI synthesized the variation in the above two parameters. Within the shaded areas, short-wave radiant components (mean standardized values of 0.104 for tree shading and 0.087 for building shading) decreased considerably more than long-wave radiant components (mean standardized values of 0.848 for tree shading and 0.851 for building shading) owing to shading; the proportion of long-wave radiant flux densities absorbed by the reference standing person was high, leading to a relatively high long-wave mean radiant temperature, and R2 between long-wave mean radiant temperature and air temperature exceeded 0.8. Moreover, the directional sky view factor (SVF) was utilized in this study, and it showed significant positive correlation with short-wave radiant flux densities, but no statistically evident correlation with long-wave radiant flux densities. Meanwhile, Tmrt was most relevant with SVFS⟶ with R2 of 0.9756. Furthermore, UTCI rose two categories at the sunlit areas compared with that at the shaded areas. In contrast, Ta and Tmrt played the first positive role in UTCI at shaded and sunlit areas, respectively.
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Staiger, Henning, and Andreas Matzarakis. "Accuracy of Mean Radiant Temperature Derived from Active and Passive Radiometry." Atmosphere 11, no. 8 (July 30, 2020): 805. http://dx.doi.org/10.3390/atmos11080805.
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The concept of the mean radiant temperature (Tmrt) allows the study of radiative exchanges between a human and its environment. It presupposes that the radiant effects on the person of the actual environment, which is generally heterogeneous, and the virtual environment, which is defined as homogeneous, are identical. ISO 7726 specifies the required accuracy in Tmrt as input of rational thermal indices, outdoors ±5 (K). Tmrt accounts for the radiant heat absorbed by skin/clothing from the shortwave (SW) and longwave (LW) spectral bands. Most of the radiant components are isotropic. However, there are anisotropic SW components; namely the direct irradiance and under clear or partly obstructed skies a significant circumsolar fraction (fcs) in the diffuse irradiance. Both originate from the close proximity of the solar disk. This study highlights the effect of fcs on Tmrt. In the scope of human biometeorology a standing body posture is standard. For unidirectional irradiances its radiant cross-section varies dependent on the solar altitude. Active radiometry in deriving Tmrt is based on measured irradiances. One method is the Klima-Michel-Modell (KMM) that uses readily available measurements from standard meteorologically radiant observations. KMM references Fanger’s area projection factors that are derived from precise measurements of real humans. Thus, KMM serves as reference in evaluation of further methods. One is the six-directional instrument (Tmrt,r,6−Dir). Slightly simplifying a standing human, it represents a subject as a rectangular solid. Tmrt,r,6−Dir is derived based on measured irradiances incident on the vertical and horizontal planes. In passive radiometry the energy balance equation of a black globe thermometer is solved that leads to Tmrt,Tg,BG. fcs significantly impacts Tmrt with noticeably reduced values for high and increased for low solar altitudes. Hence, accounting for fcs is essential for the accuracy of Tmrt. For KMM an extension to an existing algorithm is provided in order to include fcs into the Tmrt calculation that results in Tmrt,r,KMM. For Tmrt,r,6−Dir the radiant cross-section of the solid depends to a minor extent on its azimuth relative to the solar azimuth. As a result Tmrt,r,6−Dir slightly scatters compared to Tmrt,r,KMM. However, it remains within ±2 (K). Tmrt,Tg,BG compared to Tmrt,r,KMM complies only at night with the ISO 7726 bin of ±5 K. Tmrt,Tg,BG significantly overestimates Tmrt,r,KMM during the daytime, because of its greater SW absorptance compared to skin/clothing and to a smaller extent because the standing posture is represented by a sphere. Particularly in sunny conditions, Tmrt,Tg,BG is subject to considerable variance. Thus, outdoors during the daytime, Tmrt,Tg,BG is unable to serve as an appropriate input for the calculation of rational-based thermal indices.