scholarly journals Parametric Design and Comfort Optimization of Dynamic Shading Structures

2021 ◽  
Vol 13 (14) ◽  
pp. 7670
Author(s):  
Doris A. Chi ◽  
Edwin González M. ◽  
Renato Valdivia ◽  
Eduardo Gutiérrez J.

This work implements parametric tools to optimize the environmental design of urban adaptive shadings through multiobjective evolutionary algorithms that look for solutions of dynamic (time-changing) structures used in open public spaces. The proposal is located in Malecon Cancun Tajamar in the southeast part of Mexico, and the main objective is to enhance the thermal comfort of users as well as to become part of the social dynamics of the place reinforcing identity through appropriation. The proposed workflow includes four steps: (1) geometric modelling by parametric modelling tools; (2) simulation of environmental parameters by using BPS tools; (3) shape optimization by using an evolutionary algorithm; and (4) environmental verification of the results. The Universal Thermal Climate Index (UTCI) was used to assess the outdoor thermal comfort derived from the dynamic shadings. The results showed a significant improvement in the thermal comfort with absolute UTCI differences of 3.9, 7.4, and 3.1 °C at 8, 12, and 16 h, respectively, during the summer; and absolute differences of 1.4, 3.5, and 2 °C at 8, 12, and 16 h, respectively, during the winter. The proposed workflow can help to guide the early design process of dynamic shadings by finding optimal solutions that enhance outdoor thermal comfort.

Climate ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 72 ◽  
Author(s):  
Jonathan Graham ◽  
Umberto Berardi ◽  
Geoffrey Turnbull ◽  
Robert McKaye

In the context of global climate change, it is increasingly important for architects to understand the effects of their interventions on indoor and outdoor thermal comfort. New microclimate analysis tools which are gaining appreciation among architects enable the assessment of different design options in terms of biometeorological parameters, such as the Universal Thermal Climate Index (UTCI) and the Outdoor Thermal Comfort Autonomy. This paper reflects on some recent experiences of an architectural design office attempting to incorporate local climatic considerations as a design driver in projects. The investigation shows that most of the available tools for advanced climatic modelling have been developed for research purposes and are not optimized for architectural and urban design; consequently, they require adaptations and modifications to extend their functionality or to achieve interoperability with software commonly used by architects. For this scope, project-specific Python scripts used to extract design-consequential information from simulation results, as well as to construct meteorological boundary conditions for microclimate simulations, are presented. This study describes the obstacles encountered while implementing microclimate analysis in an architectural office and the measures taken to overcome them. Finally, the benefits of this form of analysis are discussed.


2021 ◽  
Vol 13 (15) ◽  
pp. 8595
Author(s):  
Lindita Bande ◽  
Abeer Alshamsi ◽  
Anoud Alhefeiti ◽  
Sarah Alderei ◽  
Sebah Shaban ◽  
...  

The city of Al Ain (Abu Dhabi, UAE) has a mainly low rise residential buildings. Villas as part of a compound or separate units represent the majority of the residential areas in the city. Due to the harsh hot arid climate of Al Ain, the energy demand for the cooling load is quite high. Therefore, it is relevant finding new retrofit strategies that are efficient in reducing the cooling load of the villas. The aim of this study is to analyze one particular strategy (parametric shading structure) in terms of design, construction, cost, energy impact on the selected villa. The main data for this study is taken from the local sources. There are six steps followed in this analysis: case study analysis; climate analysis; parametric structure and PV panels; building energy consumption and outdoor thermal comfort; modelling, simulation, and validation; materials, construction, and cost evaluation. The model of the villa was validated for the full year 2020 based on the electricity bills obtained. After adding the parametric design structure, the reduction after shading is approximately 10%. Meanwhile the UTCI (Universal Thermal Climate Index) dropped from extreme heat stress to strong heat stress (average for the month of March and September). These findings are promising in the retrofit industry due to the advanced calculations used to optimize the parametric design structure.


2020 ◽  
Vol 12 (21) ◽  
pp. 9284
Author(s):  
Jiao Xue ◽  
Xiao Hu ◽  
Shu Nuke Sani ◽  
Yuanyuan Wu ◽  
Xinyu Li ◽  
...  

Thermally comfortable outdoor spaces have contributed to high-quality urban living. In order to provide a further understanding of the influences of gender and long-term thermal history on outdoor thermal comfort, this study conducted field surveys at a university campus in Shanghai, China by carrying out microclimatic monitoring and subjective questionnaires from May to October, 2019. The analysis of collected data found that, during our survey, 57% of the occupants felt comfortable overall and 40–60% of them perceived the microclimate variables (air temperature, humidity, solar radiation, and wind speed) as “neutral”. The universal thermal climate index (UTCI) provided a better correlation with occupant thermal sensation than the physiologically equivalent temperature (PET). Females were more sensitive to the outdoor thermal environment than males. Older age led to lower thermal sensation, but the thermal sensitivities for age groups of <20, 20–50, and >50 were similar. Occupants who had resided in Shanghai for a longer period showed higher overall comfort rating and lower thermal sensation. Interviewees who came from hot summer and cold winter climate regions were less effected by the change of UTCI than those from severe cold or cold climate regions.


2018 ◽  
Vol 19 ◽  
pp. 49-57 ◽  
Author(s):  
Sajad Zare ◽  
Naser Hasheminejad ◽  
Hossein Elahi Shirvan ◽  
Rasoul Hemmatjo ◽  
Keyvan Sarebanzadeh ◽  
...  

2019 ◽  
Vol 11 (13) ◽  
pp. 3683 ◽  
Author(s):  
Xiaodong Xu ◽  
Chenhuan Yin ◽  
Wei Wang ◽  
Ning Xu ◽  
Tianzhen Hong ◽  
...  

In areas with a dry and hot climate, factors such as strong solar radiation, high temperature, low humidity, dazzling light, and dust storms can tremendously reduce people’s thermal comfort. Therefore, researchers are paying more attention to outdoor thermal comfort in urban environments as part of urban design. This study proposed an automatic workflow to optimize urban spatial forms with the aim of improvement of outdoor thermal comfort conditions, characterized by the universal thermal climate index (UTCI). A city with a dry and hot climate—Kashgar, China—is further selected as an actual case study of an urban block and Rhino & Grasshopper is the platform used to conduct simulation and optimization process with the genetic algorithm. Results showed that in summer, the proposed method can reduce the averaged UTCI from 31.17 to 27.43 °C, a decrease of about 3.74 °C, and reduce mean radiation temperature (MRT) from 43.94 to 41.29 °C, a decrease of about 2.65 °C.


2020 ◽  
Vol 172 ◽  
pp. 11001
Author(s):  
Ke Xiong ◽  
Zhenjing Yang ◽  
Canhua Cheng

In mountainous cities, walking is an important form of transportation. The microclimate environment of pedestrian streets in summer affects the comfort of pedestrians, especially in hot summer cities. Besides, there are many height differences in mountainous city pedestrian streets, while existing researches of the thermal environment were mainly aimed at plain cities. We used typology to analyze different spatial patterns and tested microclimate of five kinds of streets in the Shanchengxiang of Chongqing. Then the universal thermal climate index (UTCI) was used to evaluate the thermal comfort of different spatial spaces. Firstly, the thermal environment of the mountain city street in summer is extremely uncomfortable and needs to be improved. Secondly, the sky view factor (SVF) has a great impact on the street thermal environment. Among all kinds of streets, the one-sided open B-N (SVF = 0.474) has the worst thermal environment, with an average UTCI of 44.7℃. However, the two-sided enclosed B2-B2 (SVF = 0.052) represents a better thermal environment, with an average UTCI of 35.5℃. The R2 value of 0.88 reflects that the linear correlation between UTCI and SVF is larger than that of H/W, whose R2 value is mere 0.04. Finally, different interfaces and enclosure forms have a great impact on space thermal comfort. This study quantifies the parameters that influence the design of pedestrian streets in mountain cities from the perspective of outdoor microclimate environmental assessment and provide a reference for the sustainable design of regional streets.


2019 ◽  
Vol 282 ◽  
pp. 02010
Author(s):  
Kiran Kumar D E V S ◽  
Man Pun Wan ◽  
Mandi Zhou ◽  
Yongping Long ◽  
Bing Feng Ng

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.


Author(s):  
Claudia Di Napoli ◽  
Alessandro Messeri ◽  
Martin Novák ◽  
João Rio ◽  
Joanna Wieczorek ◽  
...  

AbstractIn operational weather forecasting standard environmental parameters, such as air temperature and humidity, are traditionally used to predict thermal conditions in the future. These parameters, however, are not enough to describe the thermal stress induced by the outdoor environment to the human body as they neglect the human heat budget and personal characteristics (e.g. clothing). The Universal Thermal Climate Index (UTCI) overcomes these limitations by using an advanced thermo-physiological model coupled with a state-of-the-art clothing model. Several systems have been recently developed to operationally forecast human biometeorological conditions via the UTCI, i.e. by computing UTCI from the forecasts of air temperature, humidity, wind speed and radiation as provided by numerical weather prediction models. Here we describe the UTCI-based forecasting systems developed in Czech Republic, Italy, Poland, Portugal and at the pan-European scale. Their characteristics are illustrated and their potential as warning systems for thermal hazards discussed.


2019 ◽  
Vol 111 ◽  
pp. 02004 ◽  
Author(s):  
Xiaojie Zhou ◽  
Sumei Liu ◽  
Xuan Liu ◽  
Xiaorui Lin ◽  
Ke Qing ◽  
...  

Thermal environment in residential kitchen in China is transient and non-uniform and with strong radiation asymmetry from gas stove. Due to the complexity of kitchen thermal environment, it is not sure if previous thermal comfort models can accurately predict the thermal comfort in residential kitchens. In order to evaluate if existing thermal comfort models can be applied for Chinese kitchens, this investigation conducted human subject tests for 20 cooks when preparing dishes in a kitchen. The study measured skin temperatures of the cooks and environmental parameters and used questionnaires to obtain their thermal sensation votes at the same time. The actual thermal sensation votes were compared with the predicted ones by four thermal comfort models: predicted mean vote (PMV) model, dynamic thermal sensation (DTS) model, the University of California at Berkeley (UCB) model, and the transient outdoor thermal comfort model from Lai et al. The results showed that all the models could predict the trend of the thermal sensations but with errors. The PMV model overpredicted the thermal sensations. The UCB and Lai’s models showed a slower change in thermal sensation votes (TSV) after turning on the stove. The DTS model was more accurate than the others in predicting the mean thermal sensation, but with a large variation in predicting individual thermal sensation votes. A better thermal comfort model should be developed for Chinese residential kitchens.


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