Calculating human thermal comfort and thermal stress in the PALM model system 6.0

Clothing Insulation ◽

Human Thermal Comfort ◽

Model Based ◽

Perceived Temperature ◽

Abstract. In the frame of the project MOSAIK – Model–based city planning and application in climate change, a German-wide research project within the call Urban Climate Under Change ([UC]2) funded by the German Federal Ministry of Education and Research (BMBF), a biometeorology module was implemented into the PALM model system. The new biometeorology module comprises of methods for the calculation of uv-exposure quantities, a human–biometeorologically weighted mean radiant temperature (Tmrt), as well as for the estimation of human thermal comfort or stress. The latter is achieved through the implementation of the three widely–used thermal indices Perceived Temperature (PT), Universal Thermal Climate Index (UTCI), as well as Physiologically Equivalent Temperature (PET) together with a newly developed instationary index instationary Perceived Temperature (iPT) based on PT for use with the multi–agent model. Comparison calculations were performed for the indices PT, UTCI and PET based on the SkyHelios model and showing PALM calculates higher values in general. This is mostly due to a higher radiational gain leading to higher values of mean radiant temperature. For a more direct comparison, the indices PT, PET and UTCI were calculated by the biometeorology module, as well as the programs provided by the attachment to the VDI guideline 3787, as well as by the RayMan model based on the very same input dataset. Results show deviations below rounding precision (less than 0.1 K) for PET and UTCI and some deviations of up to 2.683 K for PT caused by rounding leading to the selection of a different clothing insulation step in very rare cases (0.027 %).

Calculating human thermal comfort and thermal stress in the PALM model system 6.0

Geoscientific Model Development ◽

10.5194/gmd-13-3055-2020 ◽

2020 ◽

Vol 13 (7) ◽

pp. 3055-3065 ◽

Cited By ~ 2

Author(s):

Dominik Fröhlich ◽

Andreas Matzarakis

Keyword(s):

Thermal Comfort ◽

City Planning ◽

Urban Climate ◽

Climate Index ◽

Thermal Indices ◽

Large Eddy Simulation Model ◽

Human Thermal Comfort ◽

Model Based ◽

Abstract. In the frame of the project “MOSAIK – Model-based city planning and application in climate change”, a German-wide research project within the call “Urban Climate Under Change” ([UC]2) funded by the German Federal Ministry of Education and Research (BMBF), a biometeorology module was implemented into the Parallelized Large-Eddy Simulation Model (PALM) system. The new biometeorology module is comprised of methods for the calculation of UV-exposure quantities, a human–biometeorologically weighted mean radiant temperature (Tmrt), as well as for the estimation of human thermal comfort or stress. The latter is achieved through the implementation of the three widely used thermal indices: perceived temperature (PT), Universal Thermal Climate Index (UTCI), as well as physiologically equivalent temperature (PET). Comparison calculations were performed for the PT, UTCI and PET indices based on the SkyHelios model and showing PALM calculates higher values in general. This is mostly due to a higher radiational gain leading to higher values of mean radiant temperature. For a more direct comparison, the PT, PET and UTCI indices were calculated by the biometeorology module, as well as the programs provided by the attachment to Verein Deutscher Ingenieure (VDI) guideline 3787, as well as by the RayMan model based on the very same input dataset. Results show deviations below the relevant precision of 0.1 K for PET and UTCI and some deviations of up to 2.683 K for PT caused by repeated unfavorable rounding in very rare cases (0.027 %).

Design Range of Indoor Relative Humidity in Radiant Cooling Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.4905 ◽

2011 ◽

Vol 243-249 ◽

pp. 4905-4908

Author(s):

Xue Min Sui ◽

Xu Zhang ◽

Guang Hui Han

Keyword(s):

Relative Humidity ◽

Thermal Comfort ◽

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.

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 ◽

10.1155/2020/8843676 ◽

2020 ◽

Vol 2020 ◽

pp. 1-19

Author(s):

Jing Du ◽

Lin Liu ◽

Xin Chen ◽

Jing Liu

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Short Wave ◽

Radiant Flux ◽

View Factor ◽

Human Thermal Comfort ◽

Long Wave ◽

Shading Effects ◽

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.

Evaluation of Human Thermal Comfort in Offices in Kuwait and Assessment of the Applicability of the Standard PMV Model

Volume 1 ◽

10.1115/ht-fed2004-56787 ◽

2004 ◽

Author(s):

Nawaf Al-Mutawa ◽

Walid Chakroun ◽

Mohammad H. Hosni

Keyword(s):

Thermal Comfort ◽

Psychological Impact ◽

Activity Level ◽

Office Buildings ◽

Clothing Insulation ◽

Comfort Index ◽

Human Thermal Comfort ◽

The State Of Kuwait ◽

Radiant Temperature ◽

Velocity Turbulence

It has been known that the human thermal comfort is not exclusively a function of air temperature but also a function of six additional parameters, namely, mean radiant temperature, air velocity, turbulence intensity, humidity, activity level, and clothing insulation. The combined physical and psychological impact of these parameters on thermal comfort is mathematically described in various comfort models. The current comfort models, while use extensive human comfort data, may not be applicable in all world regions due to environmental conditions and people’s expectations. The State of Kuwait has a population of 2.5 million inhabitants with majority of people living in a few populated cities with heavy vehicle traffic, office buildings, factories, petroleum operations, and shopping centers. During the summer months (especially in July and August) the temperature reaches 48 °C in the afternoon, and can sometimes exceed 55 °C requiring extensive use of air conditioning. The traditional clothing (Disdasha) is made of lightweight, white, fabric material to provide some level of comfort. To better understand the regional preferences and assess the applicability of the standard comfort models in Kuwait, important parameters influencing human thermal comfort were measured in ten different government offices and the corresponding PMV indices were calculated. The results were compared with other comfort indices to obtain the most viable comfort index and the appropriate temperature range for local comfort for Kuwait offices. This study is not only important for comfort evaluations but also for evaluation of energy consumption in office buildings.

Modeling Mean Radiant Temperature Distribution in Urban Landscapes Using DART

Remote Sensing ◽

10.3390/rs13081443 ◽

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 ◽

Area Index ◽

Sensing Data ◽

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.

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

Energies ◽

10.3390/en14154530 ◽

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 ◽

Operative Temperature ◽

Neutral 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.

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

Finisterra ◽

10.18055/finis1420 ◽

2012 ◽

Vol 42 (84) ◽

Cited By ~ 2

Author(s):

Henrique Andrade ◽

Rute Vieira

Keyword(s):

Solar Radiation ◽

Thermal Comfort ◽

Green Space ◽

Urban Green Space ◽

Climatic Parameters ◽

Incident Solar Radiation ◽

Urban Green ◽

Isolated Trees ◽

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.

Experimental study on coupling effect of indoor air temperature and radiant temperature on human thermal comfort in non-uniform thermal environment

Building and Environment ◽

10.1016/j.buildenv.2019.106387 ◽

2019 ◽

Vol 165 ◽

pp. 106387 ◽

Cited By ~ 3

Author(s):

Dengjia Wang ◽

Guixia Chen ◽

Cong Song ◽

Yanfeng Liu ◽

Wenfang He ◽

...

Keyword(s):

Experimental Study ◽

Thermal Comfort ◽

Air Temperature ◽

Indoor Air ◽

Thermal Environment ◽

Coupling Effect ◽

Human Thermal Comfort ◽

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

Open Geosciences ◽

10.2478/s13533-011-0010-x ◽

2011 ◽

Vol 3 (1) ◽

Cited By ~ 40

Author(s):

Noémi Kántor ◽

János Unger

Keyword(s):

Thermal Comfort ◽

Short Wave ◽

Urban Environments ◽

Outdoor Thermal Comfort ◽

Radiation Environment ◽

Wave Radiation ◽

Radiation Fluxes ◽

The Mean ◽

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).

Transient Human Thermal Comfort Response in Convective and Radiative Environments

Heat Transfer: Volume 3 ◽

10.1115/ht2008-56101 ◽

2008 ◽

Author(s):

Mohamad Al-Othmani ◽

Nesreen Ghaddar ◽

Kamel Ghali

Keyword(s):

Thermal Comfort ◽

Thermal Conditions ◽

Activity Level ◽

Convective Heating ◽

Convective System ◽

Clothing Insulation ◽

Indoor Space ◽

Human Thermal Comfort ◽

Walking Activity ◽

Local Thermal Comfort

In this work, human transient thermal responses and comfort are studied in non-uniform radiant heating and convective heating environments. The focus was on a change from walking activity of human in outdoor cold environment at high clothing insulation to warm indoor environment at sedentary activity level associated with lower clothing insulation. A transient multi-segmented bioheat model sensitive to radiant asymmetry is used to compare how fast the human body approaches steady state thermal conditions in both radiative and convective warm environments. A space thermal model is integrated with the bioheat model to predict the transient changes in skin and core temperature of a person subject to change in metabolic rate and clothing insulation when entering conditioned indoor space. It was found that overall thermal comfort and neutrality were reached in 6.2 minutes in the radiative environment compared to 9.24 minutes in convective environment. The local thermal comfort of various body segments differed in their response to the convective system where it took more than 19 minutes for extremities to reach local comfort unlike the radiative system where thermal comfort was attained within 7 minutes.