Experimental Study on Comfort Sensation of People in the Outdoor Environment

2019

Climate

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.

Section: Evaluation Under Various Conditionsmentioning

confidence: 88%

Thermal Environment Design of Outdoor Spaces by Examining Redevelopment Buildings Opposite Central Osaka Station

2019

Climate

“…SET* is defined as the equivalent dry bulb temperature of an isothermal environment at 50% RH in which a subject, while wearing clothing standardized for the activity concerned, would have the same heat stress and thermo-regulatory strain as in the actual test environment [31], is used to evaluate the thermal environment [5]. The relationship between SET* and thermal comfort, which is based on the results of a declaration test for the outdoor comfort of Japanese people, is shown in Table 2 [52]. SET* is desirable as an index from the viewpoint of appropriately introducing adaptation measures in urban areas and developing a more comfortable outdoor space as it exhibits a good relationship with outdoor thermal comfort [53].…”

Section: Methodsmentioning

confidence: 99%

A Simple Method to Evaluate Adaptation Measures for Urban Heat Island

2018

Environments

In recent years, adaptation measures such as awnings, louvers, directional reflective materials, mist sprays, and evaporative materials, have been developed with the expectation that they will serve as effective solutions to outdoor human thermal environments that are under the influence of urban heat island. A simple method to evaluate the aforementioned adaptation measures is examined in this study, focusing on their appropriate introduction on urban space. The influence of the solar transmittance of adaptation measures such as shading, on mean radiant temperature (MRT) is approximately 1.5 • C per 0.10. If a shielding device that reflects a large amount of solar radiation and facilitates high levels of evaporation is developed, MRT and standard new effective temperature (SET*) will both decrease.

“…The evaluation results for each region at 10:00, 13:00, and 17:00 on a typical summer day are shown in Figure 7. The relationship between SET* and thermal comfort evaluation reported by Ishii et al [26] is as follows: comfortable < 26.5 • C < slightly comfortable < 27.5 • C < neither comfortable nor uncomfortable < 29.5 • C < slightly uncomfortable < 31.5 • C < uncomfortable < 32.5 • C < very uncomfortable. At 10:00 and 13:00, very uncomfortable situations are mitigated at shaded points in all areas.…”

Section: Discussionmentioning

confidence: 99%

Thermal Environmental Design in Outdoor Space Focusing on Radiation Environment Influenced by Ground Cover Material and Solar Shading, through the Examination on the Redevelopment Buildings in Front of Central Osaka Station

Kyogoku

2018

Sustainability

Abstract:The outdoor open space is used for various purposes, e.g., to walk, rest, talk, meet, study, exercise, play, perform, eat, and drink. Therefore, it is desirable to provide various thermal environments according to users' needs and their actual conditions. In this study, the radiation environment was evaluated, focusing on ground cover materials and solar radiation shading, through the examination on the redevelopment buildings in front of Central Osaka Station. The spatial distribution of solar radiation shading was calculated using ArcGIS and building shape data. Surface temperatures on the ground and wall are calculated based on the surface heat budget equation. MRT (Mean Radiant Temperature) of the human body is calculated assuming that the human body is a sphere. The most dominant factor for the radiant environment is solar radiation shielding and the next is the improvement of surface cover. It is difficult to make SET* (Standard new Effective Temperature) comfortable in the afternoon by both solar radiation shielding and improved surface cover because the air temperature is too high on a typical summer day (August). However, particularly in Rooftop Gardens and Green Garden, because the areas of shade grass and water are large, there are several places where people do not feel uncomfortable.